Earth is now the warmest it's been in some 120,000 years. Eighteen of the last 19 years have been the warmest on record. And concentrations of carbon dioxide — a potent greenhouse gas — are the highest they've been in millions of years.

The consequences of such a globally-disrupted climate are many, and it's understandably difficult to keep track. To help, here's a list of climate-relevant news that has transpired in 2019, from historically unprecedented disappearances of ice, to flood-ravaged cities.

Image: SHUTTERSTOCK / FRANK_PETERS

In early 2019, the Rhodium Group — a research institution that analyzes global economic and environmental trends — released a report finding that in 2018 carbon dioxide emissions in the U.S. rose 3.4 percent from the prior year. That's the second largest gain in the last two decades.

"It’s trending in the wrong direction — it’s not encouraging," said Robert McGrath, the director of the University of Colorado Boulder's Renewable and Sustainable Energy Institute who had no role in the report but reviewed it.

Image: GETTY IMAGES/FOTOSEARCH RF

Antarctica — home to the greatest ice sheets on Earth — isn't just melting significantly faster than it was decades ago. Great masses of ice that scientists once presumed were largely immune to melting are losing ample ice into the sea.

"People are beginning to recognize that East Antarctica might be waking up," said Josh Willis, an oceanographer at NASA's Jet Propulsion Laboratory that visits and measures Earth's melting glaciers.

"There’s growing evidence that eastern Antarctica is not just going to stay frozen and well-behaved in the next 50 to 100 years," he explained.

Image: SHUTTERSTOCK / AFRICA STUDIO

A triple whammy of disease, climate change, and deforestation has threatened around 60 percent of the planet's wild coffee species. While this hasn't yet imperiled the world's coffee supply, it jeopardizes your favorite coffee's resiliency in the face of profound planetary change.

"As farmers are increasingly exposed to new climate conditions and changing pest pressures, the genetic diversity of wild crop relatives may be essential to breeding new coffee varieties that can withstand these pressures," Nathan Mueller, an assistant professor of earth system science at the University of California, Irvine who researches global food security, said over email.

Americans find today's climate science increasingly convincing, and a damaging mix of exceptional drought, storms, and record-breaking heat is the reason why.

The results of a new survey — conducted in November 2018 by the University of Chicago's Energy Policy Institute and the research organization The Associated Press-NORC Center for Public Affairs Research — found that nearly half of Americans said today's climate science "is more convincing than five years ago, with extreme weather driving their views."

The polar vortex has become a popular phenomenon for good reason: This weakening of the polar vortex and the subsequent spillover of frigid air has become more common over the last two decades.

"We are seeing these events occurring more frequently as of late," said Jeff Weber, a meteorologist with the University Corporation for Atmospheric Research.

Although this increase in polar vortex frequency is a hot area of study, one emerging theory blames significantly diminished Arctic sea ice. The Arctic is warming over twice as fast as the rest of the globe and sea ice cover is plummeting. As a result, recent climate research suggests that — without this ice cover — more heat escapes from the oceans. Ultimately, researchers found that this relatively warmer air interacts with and weakens the winds over the Arctic, allowing frigid polar air to more easily escape to southerly places like Cleveland and New York City.

Arctic air flowing south into the U.S. on January 31, 2019. Image: CLIMATE REANALYZER/UNIVERSITY OF MAINE

While certain portions of the winter sure felt frigid, overall, the number of daily cold records set in the U.S. has been consistently dwarfed by the number of warm or high temperature records. The score isn't even close. High records over the last decade are outpacing low records by a rate of two to one.

In the past 10 years there have been 21,461 record daily highs and 11,466 lows.

"The trend is in exactly the direction we would expect as a result of a warming planet," said Michael Mann, a climate scientist at Penn State University.

A weather station in the Hindu Kush Himalaya region. Image: JITENDRA BAJRACHARYA/ICIMOD



Beyond the continually grim news from the north and south poles is the melting of the "third pole," known as the Hindu Kush Himalaya region. Spreading over 2,000 miles across eight nations (from Afghanistan to Myanmar), these mountainous lands are home to the third-largest stores of ice on the planet and provide water to hundreds of millions of people.

Under the most optimistic conditions, a new report found that over a third of the ice will vanish by the century's end. But under more extreme climate scenarios — wherein global climate efforts fail — two-thirds of these mighty glaciers could disappear, with overall ice losses of a whopping 90 percent.

"Glacier-wise, it's not a great story," Joseph Shea, one of the report's lead authors and an assistant professor of environmental geomatics at the University of Northern British Columbia, said in an interview.

The U.S. Capitol Building in Washington D.C. Image: SHUTTERSTOCK / NICOLAS AGUIAR

The U.S. House of Representatives Committee on Science, Space and Technology is no longer under the leadership of the Republican party, which is candidly opposed to globally-accepted climate science.

Congresswoman Eddie Bernice Johnson, a veteran Democratic lawmaker from Texas, has become Chairwoman and called a hearing for Feb. 13 entitled "The State of Climate Science and Why it Matters," inviting four scientists to give testimony about major U.S. climate reports and the significance of the latest climate science.

"Climate change is real, it's happening now, and humans are responsible for it," Bob Kopp, a climate scientist at Rutgers University and a coauthor of the congressionally mandated Fourth National Climate Assessment Kopp said in an interview, outlining critical points he planned to make to federal lawmakers.

In 2017 Earth's temperatures were significantly warmer than compared to the average. Image: NASA

Here's a statistic: On Earth, 18 of the last 19 years have been the warmest in recorded history.

The globe's 21st-century heating, however, becomes all the more stark when compared to the coldest years on record. As climate scientist Simon Donner, who researches human-induced climate change at The University of British Columbia, underscored via a list posted on Twitter, the planet's 20 coldest years all occurred nearly a century ago, between 1884 and 1929.

The coldest year on record occurred in 1904.

Green areas show increases in areas covered by green leaves. Image: nasa

Two NASA satellites have watched Earth grow greener over the last 20 years — in large part because China is hellbent on planting millions of trees.

Earth's greening — meaning the increase in areas covered by green leaves — has made the greatest gains in China and India since the mid-1990s. "The effect comes mostly from ambitious tree-planting programs in China and intensive agriculture in both countries," NASA wrote as it released maps of the planet-wide changes.

China kickstarted its tree-planting mobilizations in the 1990s to combat erosion, climate change, and air pollution. This dedicated planting — sometimes done by soldiers — equated to over 40 percent of China's greening, so far.

A New Deal project: the Chickamauga Dam. Image: SHUTTERSTOCK / EVERETT HISTORICAL

The scope of a Green New Deal — if such a program ever truly comes to match the scale of the original New Deal — wouldn’t just put millions of Americans to work, but could very well transform the mood, culture, and spirit of the United States in the 21st century.

The New Deal wasn’t just paying people to build things. People were doing fulfilling, nation-improving work. They planted three billion trees. They built many of the nation’s bridges and roads. Today, we drive under their tunnels and walk through their parks.

“Those men at the end of their lives would take their families back to show them what they had done — because they were quite proud of it,” said Gray Brechin, a historical geographer and New Deal scholar.

Higher CO2 concentrations swirling around Earth (shown by yellows and reds). Image: nasa

Princeton physicist and carbon dioxide-advocate William Happer joined President Trump's National Security Council as a top advisor in 2018, largely on matters related to climate change. Happer continues to assert that the planet's atmosphere needs significantly more CO2, the potent greenhouse gas that U.S. government scientists have repeatedly underscored is stoking accelerating climate change.

Because plants use carbon dioxide to live, Happer has said "more CO2 is actually a benefit to the Earth," asserted that Earth is experiencing a "CO2 famine," and concluded that "If plants could vote, they would vote for coal."

Earth and plant scientists disagree.

"The idea that increased CO2 is universally beneficial [to plants] is very misguided," said Jill Anderson, an evolutionary ecologist specializing in plant populations at the University of Georgia.

Rich Willson paddles through the miniature golf course after the flooding in in Guerneville, California. Image: KARL MONDON/MEDIANEWS GROUP/THE MERCURY NEWS VIA GETTY IMAGES

A potent atmospheric river — a long band of water vapor that often transports ample amounts of moisture to the western U.S. like "rivers in the sky" — deluged portions of Northern California in late February. The Russian River, which winds through the Sonoma County town of Guerneville, reached over 45-feet high and swamped the area, prompting the Sheriff to announce on Twitter that the town had been surrounded by water — with no way in or out.

While California relies heavily on these wintertime atmospheric rivers for its water, scientists expect these storms to grow dramatically wetter as Earth's climate heats up.

"We're likely to see rain in increasingly intense bursts," said Daniel Swain, a climate scientist at the National Center for Atmospheric Research.

Satellite imagery of the mostly ice-free Bering Strait on Feb. 28. 2019. Image: SENTINEL HUB EO BROWSER/SENTINEL 3

During winter, the Bering Strait has historically been blanketed in ice. But this year, the ice had nearly vanished [by late February].

"The usually ice-covered Bering Strait is almost completely open water," said Zack Labe, a climate scientist and Ph.D. candidate at the University of California at Irvine.

"There should be ice here until May," added Lars Kaleschke, a climate scientist at the Alfred Wegener Institute for Polar and Marine Research.

Sunlight reflecting off the Earth. Image: nasa

Solar geoengineering is widely viewed as risky business.

The somewhat sci-fi concept — to use blimps, planes, or other means to load Earth's atmosphere with particles or droplets that reflect sunlight and cool the planet — has crept into the mainstream conversation as a means of reversing relentless climate change, should our efforts to slash carbon emissions fail or sputter. But geoengineering schemes come with a slew of hazards. A number of studies have cited the ill consequences of messing with Earth's sun intake, including big falls in crop production, the likelihood of unforeseen adverse side effects, and critically, a weakened water cycle that could trigger drops in precipitation and widespread drought.

Yet new research, published in the journal Nature Climate Change, acknowledges these problems but finds a potential fix: only deploying enough reflective specks in the atmosphere to reduce about half of Earth's warming, rather than relying on geoengineering to completely return Earth to the cooler, milder climate of the 19th century. In other words, giving Earth a geoengineering dose that would reverse a significant portion of the warming, but not enough to stoke the problematic side effects.

"Solar engineering might not be a good choice in an emergency," said David Keith, a solar engineering researcher at Harvard University and study coauthor. "If it makes any sense at all, it makes sense to gradually ramp it up."

With no benefit to itself, Earth's vast sea has gulped up around 30 percent of the carbon dioxide humans emitted into Earth's atmosphere over the last century. Critically, scientists have now confirmed that the ocean in recent decades has continued its steadfast rate of CO2 absorption, rather than letting the potent greenhouse gas further saturate the skies.

But a weighty question still looms: How much longer can we rely on the ocean to so effectively store away carbon dioxide, and stave off considerably more global warming?

"At some point the ability of the ocean to absorb carbon will start to diminish," said Jeremy Mathis, a National Oceanic and Atmospheric Administration (NOAA) climate scientist who coauthored the study. "It means atmospheric CO2 levels could go up faster than they already are."

"That's a big deal," Mathis emphasized.

Flooding in Nebraska as seen from space on March 16, 2019. Image: nasa

In 1948, Air Force Secretary Stuart Symington stationed the United States' long-range nuclear bombers at Offutt Air Force Base in eastern Nebraska, a location safe in the middle of the nation and well-insulated from the coast.

But 70 years later, the base — now home to the U.S. Strategic Command which deters "catastrophic actions from adversaries and poses an immediate threat to any actor who questions U.S. resolve by demonstrating our capabilities" — isn't safe from historic and record-setting floods.

Extreme weather has flooded large swathes of Nebraska and a full one-third of the Offutt Air Force Base. NASA's Landsat 8 satellite captured before and after images of the flooding — which the European Union Earth Observation Programme called "biblical."

Exceptionally low water levels in Lake Mead reveal a white "bathtub ring." Image: Shutterstock / OSDG

Out West, the future is dry.

Amid an unprecedented 19-year drought in the expansive Colorado River Basin — which supplies water to 40 million Americans — seven Western states have acknowledged that the 21st century will only grow drier as temperatures continue to rise. And that means less water in the 1,450-mile Colorado River. On Tuesday, water managers from states including California, Utah, and New Mexico announced a drought plan (formally called a Drought Contingency Plan), which cuts their water use for the next seven years — until an even more austere strategy must be adopted.

"The old ways of managing water in the West aren’t working and won’t work in the 21st century," said Brad Udall, a senior water and climate research scientist at Colorado State University.

The Jakobshavn glacier in 2014 as viewed from space. Image: NASA EARTH OBSERVATORY IMAGES BY JESSE ALLEN AND ROBERT SIMMON

Like a snake slithering back into its den, Greenland's lengthy Jakobshavn glacier has retreated over 25 miles since the 19th century. And for the last two decades, this warming river of ice has purged more ice into to sea than any other Greenland glacier.

But since 2016 — and after 20 years of unprecedented melting in Greenland — Jakobshavn's rapid retreat has slowed down considerably and the glacier has even grown bigger. This might appear to be a rare dose of good news for the Arctic — a place that's heated up over twice as much as the rest of the planet.

But no.

NASA-led scientists discovered that Jakobshavn's stagnated melt is only a temporary blip brought on by cooler ocean currents. Though worryingly, the recent slowing also carries ominous news for the thawing landmass. The research, published Monday in the journal Nature Geoscience, reveals that the Jakobshavn glacier — whose ice reaches some 2,600 feet under the sea — is extremely sensitive to changes in ocean temperature. That's a big problem because the dynamic ocean currents off western Greenland will naturally warm up again — on top of the reality that Earth's absorbent seas soak up over 90 percent of the planet's accumulating heat. These incessantly warming waters spell a grimmer future for both Jakobshavn and Earth's rising seas.

"The big story here is the ocean," said Josh Willis, a study coauthor who heads NASA's Oceans Melting Greenland mission. "The ocean is playing a powerful role in driving the ice loss in Greenland, particularly Jakobshavn."

Temperatures in the Arctic on March 25, 2018 were 10 degrees F above average. Image: CLIMATE REANALYZER / UNIVERSITY OF MAINE



It was unusually warm in The Last Frontier.

Large swaths of Alaska have seen record or near-record warmth this March said Rick Thoman, a climate specialist at the Alaska Center for Climate Assessment and Policy. And the trend isn't quitting.

Daily temperature records broke around the state, and toppled all-time March records in the greater Arctic region. Alaska even saw its earliest ever 70-degree Fahrenheit temperature.

This exceptional warmth has been stoked by a mix of weather events and a rapidly warming climate.

"The magnitude and persistence of the warmth is particularly striking to me this winter in parts of Alaska," Zack Labe, a climate scientist and Ph.D. candidate at the University of California at Irvine, said over email.

Sea ice in the Arctic: 2014 on left, versus 2019 on right. Image: noaa

Early spring is the time of year that Arctic sea ice often reaches its greatest size, freezing over the vast northern ocean. But in 2019, this ice cover — called the maximum ice extent — is meager, particularly in the usually ice-clad Bering Sea.

The National Oceanic and Atmospheric Administration (NOAA) released a comparison of Bering and Chukchi sea ice in 2014 (a normal year) versus the maximum sea ice extent this year. As you can see, where there is supposed to be ice, there is a great open ocean — months ahead of schedule.

It's the lowest sea ice extent on record for the Bering Sea.

"The changes in the Arctic are happening faster than they’re happening anywhere else on the rest of the planet," Jeremey Mathis, a NOAA oceanographer, told Mashable.

With a still-emerging Green New Deal stalled in the Senate — and nearly two decades after the U.S. released its first congressionally-mandated climate report — the U.S. still has no long-term, coherent climate plans.

Meanwhile, across the pond, Europe is on track to slash its carbon emissions by 2030 to around 50 percent of 1990 levels: Already, the European Union has made binding pledges to cut its greenhouse gas emissions by at least 40% by 2030 — though a new analysis by the UK climate policy group Sandbag shows the European nation states can get to 50 percent by then — or higher.

Can the U.S. get there?

"We can achieve those cuts," said John Quigley, the director of the Center for Environment, Energy and Economy at Harrisburg University. "It’s purely a matter of political will. We don’t have any, at least, on the federal level."

Young witnesses testifying in front of the House Select Committee on the Climate Crisis. Image: HOUSE SELECT COMMITTEE ON THE CLIMATE CRISIS

There's a brand new committee in the U.S. House of Representatives — the Select Committee on the Climate Crisis — and the group used its first-ever hearing to call on four young environmental leaders to testify. Their age is particularly relevant, as these youthful citizens are destined to experience the worsening consequences of a globally disrupted climate.

The young witnesses cited many of the same events that have been documented by scientists, such marked increases in extreme precipitation and flooding, smoke-inundated cities, and vanishing coastlines.

“It takes a huge toll on our economy,” said 18-year-old Chris Suggs, noting that U.S. Route 70 in North Carolina — a main corridor — has gone underwater.

The world's total ice loss between 1961 and 2016. Image: EUROPEAN SPACE AGENCY / ADAPTED FROM ZEMP ET AL. (2019) NATURE / DATA COURTESY OF WORLD GLACIER MONITORING SERVICE

Nine trillion metric tons.

That's how much ice Earth's glaciers lost in the 55 years between 1961 and 2016. An international team of scientists used satellite and direct field observations to conclude that Earth's glaciers have melted such a profound sum of ice in the last half-century. They published their report in April in the journal Nature.

If one were to assume an average weight of 735,000 pounds for a 747 airliner (not the colossal Alaskan bear), that comes out to around 27 billion 747s worth of ice lost over this period.

Image: Getty Images

Beyond the blight and recycling woes wrought by society's plastic bag addiction, plastics have an effect that bears heavy weight for the future. Overall, global plastic consumption has quadrupled in the last 40 years, and if the consumption of these fossil fuel-made plastics continues apace, the industry will carry a massive carbon emissions load by 2050.

Specifically, if modern civilization ever manages to cap the planet's total warming at around 2.7 degrees Fahrenheit above 19th century levels — which would limit the worst consequences of a globally disrupted climate — the plastics industry would account for a whopping 15 percent of the total amount of carbon society can expel into the atmosphere. In a world where cars, planes, ships, electrical generation, cement-making, and belching cows all contribute sizable carbon emissions, 15 percent from plastics is an oversized, if not ridiculous, contributor.

"We need an unprecedented scale of effort," said Sangwon Suh, a professor in industrial ecology at the University of California at Santa Barbara.

Image: nasa

When Americans celebrated the first Earth Day on April 22, 1970, the planet's atmosphere was markedly different than it is today. Nearly 50 years ago, scientists measured Earth's levels of carbon dioxide — the planet's most important greenhouse gas — at around 325 parts per million, or ppm.

Now, almost five decades later, that number has shot up to around 412 ppm, nearly 90 ppm higher. It's a change atmospheric researchers, geologists, and climate scientists call unparalleled in at least 800,000 years, though it's likely carbon dioxide levels haven't been this high in millions years.

"The rate of CO2 increase since the first Earth Day is unprecedented in the geologic record," said Dan Breecker, a paleoclimatologist at The University of Texas at Austin.

The last five years have been the five warmest on record. Image: nasa

In a study published in the American Geophysical Union journal Earth's Future, researchers argue that meeting Paris Agreement 2 C climate targets is currently far, far out-of-reach, to put it gently. Even if the four biggest carbon-emitters — the U.S., China, the EU, and India — succeeded in dramatically ramping down their emissions over the next few decades, the rest of the world would need to radically cut their carbon emissions to nearly zero by 2030 — and stay there. That's nearly impossible.

"Even if you could achieve emission reductions — which is itself a Herculean task — very little is left over for the rest of the world," said Christopher Green, an environmental economist at McGill University and study coauthor.

"There would be almost nothing left over for the rest of the countries to emit."

A tropical sweet lip (Plectorhinchus). Image: SHUTTERSTOCK / BLUE-SEA.CZ

There are 3,800 big thermometers floating in the ocean, and the readings don't lie: Over 90 percent of the warming created by humans is soaked up by the seas. Unsurprisingly, many creatures are feeling the heat.

In new research published in April in the journal Nature, scientists found that global warming has forced twice as many marine species than land species to vanish from their hotter habitats —particularly near the already balmy equator. All the species examined were cold-blooded, or ectotherms.

"What we found so surprising is that global warming hits sea creatures the hardest," said Malin Pinsky, an evolutionary ecologist at Rutgers University and lead author of the research.

Everyone has got an AC unit. Image: Shutterstock

About 1.6 billion AC units hum on the planet today. By 2050, that number will likely swell to over 5 billion.

Roland Dittmeyer, an engineer at Germany's Karlsruhe Institute of Technology, sees a lot of potential here. AC units, especially in big residential or commercial buildings, suck in masses of air, sometimes all day long. In a paper published in April in the journal Nature Communications, Dittmeyer and a team of researchers propose that AC units be employed for a dual purpose: gulping the potent heat-trapping gas carbon dioxide out of the air while also cooling homes and offices.

"We have something that can be applied in the place that you live, or in the place that you work," said Dittmeyer.

Charred trees amid verdant regrowth. Image: Mark Kaufman / Mashable

With 1.8 million acres burned, 2018 was California’s worst fire season on record. It’s mounting evidence that even in historic fire country, a more potent fire regime has emerged out West. Overall, wildfires in the U.S. are burning twice as much land as they were in the early 1980s and they’re burning for weeks, not days, longer.

Yet in California and beyond, the indifferent, natural world will largely renew, sometimes in a matter of months. In the far West, where fires are king, it’s our society — our campgrounds, historic sites, homes, and, most importantly, lives — that will suffer. The wild world, on the other hand, will largely rise from ashes, sometimes gloriously.

“These systems have been programmed to respond [to wildfire] for millennia,” said John Baily, a fire ecologist at Oregon State University.

“Fire is reality. It always has been.”

Liftoff. Image: AP / SHUTTERSTOCK

SpaceX launched the Orbiting Carbon Observatory-3 (OCO-3) to the International Space Station (ISS) on May 3 aboard the company's dependable Falcon 9 rocket. After NASA's cargo load arrives at the ISS, astronauts will use a long robotic arm to attach the refrigerator-sized instrument to the side of the earth-orbiting station.

OCO-3 will peer down on Earth, keeping tabs on the planet's amassing carbon dioxide emissions, which are now at their highest levels in millions of years.

"Carbon dioxide is the most important gas humans are emitting into the atmosphere," Annmarie Eldering, the project scientist for OCO-3 at NASA's Jet Propulsion Laboratory, told Mashable in February. "Understanding how it will play out in the future is critical."

A glacial lake formed from melted ice and snow. Image: nasa

Scientists aboard a NASA airplane swooped over some of Greenland's largest glaciers in early May, spotting melted ice and raging rivers.

It's significant, because though it wasn't nearly summer, large blue ponds had already formed on the icy ground. NASA’s Operation IceBridge researchers observed this as part of their mission to watch for changes in Earth’s giant masses of polar ice. Greenland, in particular, has been melting at an accelerated rate for some two decades.

"Although the story of the summer of 2019 in Greenland hasn’t yet been written, it's starting on a worrying note," said Joe MacGregor, the project scientist for Operation IceBridge.

Weather forecaster Mike Nelson providing stormy updates on May 7, 2019. Image: THE DENVER CHANNEL VIA YOUTUBE

Unable to avoid the atmospheric realities they scrutinize each day, a growing contingent of meteorologists are now looking well beyond the 10-day forecast, to Earth's troubling climate trends. They hold a powerful audience, as over half of Americans receive their news from television. But these forecasters are not simply referencing climate change; they're regularly providing viewers with the cold, hard, and perhaps unpleasant facts, like record CO2 numbers.

"It's important for us to get the right science out there," said Denver 7's Nelson, who then paused, and considered another reason why he's presenting CO2 levels. "I’ve been doing it, increasingly, since the birth of my grandchildren."

Image: SHUTTERSTOCK / GERALD ROBERT FISCHER

Pilots flying at high altitudes need extra oxygen, or they'll start to lose vision — and eventually pass out.

Similarly, creatures dwelling in the oceans also require oxygen to see. Unfortunately for them, the seas are now gradually losing oxygen, a problematic marine event known as deoxygenation. Recognizing that this loss of oxygen could also cause blindness in sea organisms, scientists at the Scripps Institution for Oceanography tested how reduced oxygen levels impacted the vision of squid, octopus, and crab species. Their results, published in the Journal of Experimental Biology, showed that these organisms did indeed experience varying degrees of blindness, including near total blindness.

"It's a pretty significant issue in the oceans because organisms rely on oxygen to survive," said Lillian McCormick, a marine scientist at Scripps and lead author of the study, emphasizing that oxygen is needed for more than breathing. "Vision is a very demanding sensory process. It requires oxygen to function."

Bill Nye dropped a slew of F-bombs.

As a guest on the May 12 episode of Last Week Tonight With John Oliver, the storied science communicator used profanity and half-jest to make a succinct point about Earth's rising carbon dioxide emissions, which are now at their highest levels in millions of years: CO2, a potent greenhouse gas, will continue to relentlessly trap heat on the planet unless the U.S. and the rest of the world ambitiously slash their carbon emissions.

As of now, global nations have little to no hope of curbing Earth's warming at levels that would limit the worst consequences of climate change.

"By the end of this century, if emissions keep rising, the average temperature on Earth could go up another four to eight degrees," said Nye.

"What I'm saying is the planet is on fucking fire."

The Trump administration no longer wants many federal scientists to consider longer-term consequences of saturating the atmosphere with the potent heat-trapping gas carbon dioxide, now likely at its highest level in millions of years.

As The New York Times reported in May, the head of the U.S. Geological Survey (USGS) ordered the agency's researchers to only project climate change impacts through 2040, as opposed to the end of the century. What's more, The Times reported that the Trump administration might not include future high carbon emission scenarios (which are quite likely) in forthcoming climate reports, including the congressionally mandated National Climate Assessment — a major report closely reviewed by The National Academies of Sciences, Engineering, and Medicine.

These actions boil down to withholding climate modeling research that's being done at advanced research centers, universities, and government agencies around the nation.

"These models are based on physics that have been developed over the course of a century," said Bob Kopp, an author of the Fourth National Climate Assessment, released in November 2018.

"These are not random number generators. They're analogous to models used to simulate how an airplane flies," added Kopp, who is also the director of the Institute of Earth, Ocean, and Atmospheric Sciences at Rutgers University.

Wildfire smoke hit the UK on June 3, 2019. Image: UK Met office

In May, the skies in Edmonton, Canada were so red and smoky that a local meteorologist told NASA "it looked like we were on Mars."

That prodigious wildfire smoke then left Canada, streamed thousands of miles across the Atlantic Ocean, and passed over the UK. In early June, the UK Met Office posted imagery of the North American wildfire smoke sailing over the island nation.

The early-season Canadian fires, which smothered much of Alberta in wildfire smoke in May, are consistent with wildfire research which concludes that, as temperatures climb and fire weather increases, the burning season is expected to grow longer and fuel "larger and more intense fires."

"The climate is changing," Mike Flannigan, a fire scientist at the University of Alberta, told Mashable in December, after the destructive 2018 fire season. "We’re getting more extreme weather for fire, and there are more people on the landscape," he added, noting that the problem is confounded by people moving into fire country.

The Scripps Institution of Oceanography and the National Oceanic and Atmospheric Administration (NOAA) announced on June 4 that the average carbon dioxide concentration in the atmosphere during May rounded to 414.8 parts per million, or ppm — the highest monthly number on record and the peak of 2019.

But 414.8 ppm, while the highest monthly CO2 level in recorded history, is not the only number that's critical to appreciate. The other is 3.5 ppm. That, noted Scripps, is the leap in CO2 ppm since last May. It's the second highest year-to-year jump on record, and smashes average CO2 increases from earlier decades. After the Scripps monitoring station atop Hawaii's towering Mauna Loa went online in 1959, CO2 rose around just 0.7 ppm per year in the early decades of operation. Then, in the 1990s, the rate increased to 1.5 ppm per year. The last decade has averaged 2.2 ppm.

Yet, in the last year, it was a 3.5 ppm gain. Concentrations of the planet's most influential greenhouse gas are accelerating.

"It's extremely alarming to see atmospheric CO2 continuing to increase relentlessly year after year when all scenarios that lead to a stable climate require that it go down," said Sarah Green, an environmental chemist at Michigan Technological University.

New York City Image: GETTY IMAGES / ISTOCKPHOTO

Heat waves kill more Americans than any other weather event.

Yet, as average temperatures continue their relentless rise, the U.S. government expects urban dwellers to experience more heat extremes, some unprecedented. Scientists, however, found that limiting Earth's warming this century to 2.7 degrees F (1.5 degrees Celsius) above pre-industrial temperatures will spare thousands of Americans during the hottest heat waves (events that on average hit once every 30 years). The research, published in June in the journal Science Advances, found that 2720 deaths could be avoided in the most populous metropolis, New York City.

"We all know high temperatures kill," said Eunice Lo, lead author of the study and a research associate at the University of Bristol. "We have all read news about people that have died from extremely high temperatures. But I don’t think we are particularly aware of how many deaths could occur from extremely high temperatures."

There will be as many as 12 Democratic presidential debates over the next year. But none of them will be devoted to climate change — for now, anyway.

Presidential candidate Jay Inslee — who is running as a climate change candidate with a deeply developed plan to transform the nation's energy system and rapidly slash carbon emissions — had urged the Democratic National Committee (DNC) to host a debate dedicated exclusively to climate change. But on June 5 Inslee announced that his campaign received a call from the DNC "letting us know that they will not host a climate debate."

"I remain deeply disappointed that the DNC has chosen not to listen to these Democrats, and has threatened to punish candidates who would participate in an outside climate debate," Inslee said in a June 6 statement.

A wildfire burning at night in the Mendocino National Forest in July 2018. Image: U.S. FOREST SERVICE / CECILIO RICARDO BY MARK KAUFMAN 5 DAYS AGO

410,203 acres burned.

Last summer, the Ranch Fire — which was part of a greater complex of fires — ripped through Northern California, smashing the previous, short-lived record for the largest wildfire in state history by some 128,000 acres.

And it all started because a hammer, used to drive a stake into the ground, tossed either sparks or bits of hot metal onto the parched land. The Golden State's fire protection agency, Cal Fire, revealed the historic conflagration's cause on June 6 and posted the incident report online.

A polynya in September 2017. Image: nasa

It’s a strange thing. In the dead of the subzero Antarctic winter, when the oceans at the bottom of the world are frozen over, scientists have observed massive holes the size of South Carolina or larger opening up in the sea ice.

The rare, puzzling phenomena occurred most recently in the winters of 2016 and 2017, though considerably larger holes opened up in the 1970s. Now, scientists have a good grasp of why such great holes, known as polynyas (Russian for "hole in the ice"), form.

And there's growing evidence that these striking bouts of warming might start happening more often.

"We might start to see these things more often," said Ethan Campbell, lead author of the research and a University of Washington Ph.D. student in physical oceanography.

Melt ponds on the Arctic ice. Image: JEREMY MATHIS / NOAA

Records are falling at the top of the world.

The Arctic summer has a long way to go, but already sea ice levels over great swathes of the sprawling Arctic ocean are at historic lows for this time of year. The most striking declines are in the Chukchi and Beaufort seas, located above Alaska.

The melt is exceptional, but right in line with accelerating melting trends occurring as the Arctic warms.

"Every year we smash a record that we’re shocked at," said Jeremy Mathis, a longtime Arctic researcher and a current board director at the National Academies of Sciences.

Melted sea ice in Greenland. Image: STEFFEN M. OLSEN

The melting Arctic is on dramatic display.

At mid-June, Arctic sea ice was at a record low for this time of year, and melted ice is especially notable both in and around Greenland — home to the second largest ice sheet on the planet. Steffen Olsen, a climate researcher at the Danish Meteorological Institute, snapped a photo of Greenland sea ice that had melted into a large lake of aqua water, pooled atop the icy surface.

Olsen, along with local hunters, had to sled across the flooded ice to retrieve vulnerable weather and ocean monitoring equipment. Their sled dogs splashed through the icy water.

A declassified satellite photo of the Himalayas. Image: JOSHUA MAURER / USGS

Metal canisters filled with top-secret satellite photos plummeted from space and then parachuted over the Pacific Ocean during the '70s and '80s. A U.S. Air Force plane would swoop down on cue and snag the classified material, ferrying the images safely back to land.

The spy satellite missions, run by the National Reconnaissance Office, sought to capture wide-ranging views of what transpired around the globe. In all, they photographed some 877 million square miles of Earth. The black and white photos, now declassified, have great scientific value: They reveal the accelerated melting of the colossal Himalayan glaciers — home to the third largest ice sheets on the planet.

"We’re not trying to figure out whether the glaciers will melt in the future," said Alex Gardner, a NASA glaciologist who had no role in analyzing the Cold War-era images. "We're just trying to find out how much and how fast."

Greenland's lower Kangerdlugssup Glacier in May 2019. Image: Nasa

New Arctic research — enhanced by NASA's recent aircraft observations of Greenland — found that the melting land mass is expected to incur profound ice losses this century and beyond, should carbon emissions continue to saturate the skies.

Yet, humanity has an immediate say in the matter.

"We can actually choose how it's going to look," said Andy Aschwanden, the study's lead author and researcher at the University of Alaska Fairbanks' Geophysical Institute. "The next couple decades are quite important to the future."

Pumpin' for oil. Image: SHUTTERSTOCK / ARTPHOTOCLUB

The U.S. fracking revolution is in high gear, and nearly-endless bounties of liquid gold lie beneath the West Texas ground. Overall, U.S. crude oil production and exports have both hit record highs. America is also now the world leader in natural gas production.

Jay Inslee — the presidential candidate running a climate change-focused campaign — proposed an ambitious solution in June: rapidly phasing out the extraction of fossil fuels in the U.S., which includes ending fossil fuel drilling on federal land, terminating "outrageous" taxpayer-footed subsidies to fossil fuel business (at the tune of some $26 billion a year), and pursuing a complete, nationwide ban on fracking.

"American fossil fuel production is stepping on the accelerator at just the moment that it should be hitting the brakes," reads Inslee's "Freedom from Fossil Fuels" proposal.

Miami Beach. Image: SHUTTERSTOCK / FOTOMAK

Ten Democratic presidential contenders took the debate stage in Miami on June 26. Some of them may have noticed that the weather in town was unusually hot.

Normally, temperatures in Miami around June's end max out at around 90 degrees Fahrenheit, explained Brian McNoldy, a senior research associate at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science. But the coastal city had six consecutive days where the high temperature hit at least 94 degrees. On June 24 the temperature hit 98 degrees (the second hottest day in Miami's recorded history).

Daily temperature records have fallen in the area, which is expected these days.

"The warming climate does certainly play a role in setting new records," McNoldy said. "The baseline temperature is warmer than it was decades ago, so record lows rarely happen, while record highs are happening with increasing frequency."

Hot temperatures over Europe on June 26. Image: Windy.com

The heat arrived.

As predicted, a potent heat wave settled over Europe at June's end, bringing abnormally high June temperatures to vast swathes of France, Spain, Germany and beyond — home to hundreds of millions. The highest ever recorded June temperatures toppled in Germany, France, and Poland, reaching into the triple digits at the end of the month.

Radzyń, Poland hit nearly 101 degrees Fahrenheit, a region outside of Berlin reached 101.5 degrees, and the average max June temperature in France hit its highest point ever, at nearly 95 degrees. On June 27, France peaked at over 107 degrees.

Over the last century, Europe has increasingly experienced heat waves, and since 1500 AD, the region's five hottest summers have occurred in 2018, 2016, 2010, 2003, and 2002. Expectedly, temperature records will continue to break as Earth's overall average temperatures continue their relentless, accelerated rise.

"Heat records do of course happen much more frequently due to global heating," said Stefan Rahmstorf, head of Earth System Analysis at the Potsdam Institute for Climate Impact Research in Germany. "That is entirely as expected, and it will continue as long as we heat the planet by adding greenhouse gases to the atmosphere."

Avenue des Champs-Élysées in Paris. Image: SHUTTERSTOCK / EKATERINA POKROVSKY



Records have fallen.

On June 28, France's meteorological agency, Meteo France, announced a new record high temperature of 114.6 degrees Fahrenheit (45.9 Celsius) in the baking nation, set in the southeast part of the country. Before then, the nation's all-time record was 111 degrees.

France has validated temperature records going back 150 years. (And in Paris, records go back to 1658, when Louis the Great reigned over the nation.)

France isn't alone. A potent heat wave has settled over Europe this week, with a nexus of weather and climate conditions producing record temperatures. Heat waves in Europe, however, are increasing in both frequency and intensity.

Dead trees in Sequoia National Forest in December 2017. Image: U.S. FOREST SERVICE

The number, so far, is over 147 million dead.

California's expansive forests have experienced a profound tree die-off since 2010, exacerbated by a long drought between 2012 and 2015. These pine trees are tough, though, and have evolved to withstand parched years in the drought-prone Golden State. But not drought like this, which was amplified by the planet's relentless, accelerating warming.

"The rules are changing," said Nathan Stephenson, a U.S. Geological Survey forest ecologist who monitors trees in California's Sierra Nevada mountain range.

"It wasn't just dry — it was warmer," added Craig Allen, a research ecologist with the U.S. Geological Survey.

A park bench underwater in Washington, D.C. on July 8, 2019. Image: AFP / GETTY IMAGES

Even the White House is leaking.

Potent storms deluged the Washington, D.C. area on July 8, marooning drivers atop their vehicles, transforming boulevards into brown rivers, filling parking garages with water, and dumping rainwater into the Metro.

The swampy capital certainly has a rich history of pummeling storms and flash floods, though the heaviest downpours have shot up by over 70 percent in the Northeast and 27 percent in the Southeast since the late 1950s. In large part, this is because today's atmosphere holds more water vapor than decades ago. Specifically, for every 1 degree Celsius (1.8 degrees Fahrenheit) of warming, the air can hold 7 percent more water — resulting in more heavy rain events. Earth has already warmed by more than 1 degree C since 1880.

Image: VICKY LETA / MASHABLE

On June 26, as a potent heat wave settled over Europe, atmospheric scientist Patrik Winiger also settled into his seat aboard a high-speed electric train traveling from Zurich to Amsterdam. The heat, which would soon topple temperature records across the continent, began to stress the sleek Deutsche Bahn train....

A conception of Viking ships traveling over the ocean. Image: SHUTTERSTOCK / VLASTAS

Viking settlers abandoned Greenland some 600 years ago. But the frozen ground has preserved centuries of the seafarers' hardy existence on the western shores of the remote landmass, including bones and DNA.

The Vikings, though, didn't first step foot on Greenland. The Saqqaq people arrived there first, around 3,800 years before the Vikings, as did other nomadic peoples. Yet now, all of their culturally invaluable organic remains are under threat from amplified Arctic warming — the fastest changing region on Earth.

Archaeologists, geochemists, and climate scientists traveled to Greenland and collected soil samples from seven archaeological areas to determine how vulnerable the sites are to warming. Their research, published July 11 in the journal Scientific Reports, found these organic archaeological remains (also known as organic carbon) will accelerate their decay as they become exposed to increasingly warmer climes and hungry microorganisms.

"If temperatures go up, degradation rates will increase," said Jørgen Hollesen, lead author of the research and a senior researcher at the National Museum of Denmark.

A fire in Greenland on July 10. Image: nasa

The World Meteorological Organization called the wildfires burning around the Arctic in mid-July "unprecedented." The United Nations agency noted that over 100 intense fires burned in the Arctic Circle alone over the past six weeks, releasing more carbon dioxide into the atmosphere than Sweden does in an entire year.

A rare fire even ignited in Greenland, amid unusually hot and dry weather.

Amplified wildfires are an expected, predictable consequence of a warming climate. This is all the more true in the Arctic, a sprawling region that is heating up twice as fast as the rest of the globe. The profound changes here can be easily observed over the Arctic ocean, too, where sea ice has broken records for melting throughout the 2019 summer.

Over the course of 10 days in July, Alaskan wildfires burned an area of land the size of Rhode Island. This is way above normal — though this doesn't yet match Alaska's extreme burning of 2015.

Average June temperatures in 2019. Image: nasa

In 139 years of record-keeping, this June was the warmest June ever recorded. But June 2019 also revealed a deeper warming reality.

The first half of 2019, January through June, finished up as the second warmest half-year on record, newly released NASA data shows. On top of that, each of the last five January through Junes are now the five warmest such spans on record. Only 2016 started off hotter than 2019.

"At this point, the inexorable increase in global temperatures is entirely predictable," said Sarah Green, an environmental chemist at Michigan Technological University. She noted that NASA's updated data is added proof that climate models have accurately predicted Earth's continued warming as heat-trapping gasses amass in the atmosphere.

Iceberg B-46 breaking off from Pine Island Glacier in 2018. Image: NASA / U.S. GEOLOGICAL SURVEY

To potentially thwart an irreversible collapse of the West Antarctic ice sheets, environmental physicists at the Potsdam Institute for Climate Impact Research released research on July 17 suggesting a grandiose geoengineering project. They assessed the strategy of pumping in trillions of tons of ocean water and then using snow cannons to blow massive amounts of artificial snow over the ice shelves. This would, they argue, stabilize the ice and halt the retreat. Yes, it's an intentionally far-fetched idea, and illustrates the profound difficulty of solving such a challenging environmental problem.

"It shows how huge the problem is," said Anders Levermann, an author of the study and head of the Complexity Science research department at the Potsdam Institute for Climate Impact Research.

"We are not necessarily proposing it, but it's an option," Levermann added.

Forecasted heat index for July 20, 2019. Image: Noaa / nws

Tens of millions of Americans felt triple-digit heat between July 18 and July 21.

Although climate change doesn't produce weather — like sprawling fronts of unusually warm air, hurricanes, or wildfire conditions — it does make these events worse. Any heat wave today, for example, is sitting atop boosted global temperatures. These elevated temperatures are responsible for June 2019 being the warmest June in 139 years of record-keeping, and 18 of the 19 warmest years on record occurring since 2001.

This added heat means more record hot weather becoming not just possible, but occurring more frequently. "A barely noticeable shift in the mean temperature from global warming can end up turning a 'once-per-decade' heatwave into a 'once-per-year heatwave' pretty easily," Patrick Brown, an assistant professor in the Department of Meteorology and Climate Science at San Jose State University, said over email.

Image: SHUTTERSTOCK / DOMINIC GENTILCORE

Megadroughts, persisting for decades at a time, parched the Southwestern U.S. centuries ago between 800 CE and 1600 CE. Then, the extreme droughts stopped.

But with temperatures today both exceeding the warm climes of past droughts and now relentlessly rising, the return of the Southwestern megadroughts is almost assured. New research, published July 24 in the journal Science Advances, illustrates how a timely confluence of warm temperatures and changes in the ocean stoked a cluster of 14 potent Medieval-era megadroughts.

Similar events could unfold again.

"This is what we would expect to happen in the future too," said Nathan Steiger, an associate research scientist at the Lamont-Doherty Earth Observatory of Columbia University and lead author of the study.

Temperatures on June 24, 2019. Image: windy.com

After a June heat wave smashed national temperature records in France and broke historic June records across Europe, a mass of hot air returned to the continent.

On July 24, the Netherlands Meteorological Institute reported that the nation's all-time temperature record, which stood for the last 75 years, fell as temperatures hit 101.8 degrees Fahrenheit (38.8 C).

Belgium broke its national heat record too, as temperatures reached 103.8 F (39.9 C), reported David Dehenauw, the head of forecasting at the Royal Meteorological Institute of Belgium. And the the German Meteorological Service announced its highest temperature in recorded history, of 104.9 degrees Fahrenheit (40.5 C).

Temperature anomalies on July 25, 2019. Image: CLIMATE CHANGE INSTITUTE / UNIVERSITY OF MAINE / CLIMATE REANALYZER

Paris. Germany. The Netherlands. Belgium.

The second potent heat wave to hit Europe in the span of a month is currently toppling all-time temperature records in a region that keeps many of the oldest weather records in the world. A number of national records broke on July 24, but Thursday, July 25, shaped up to be even hotter.

"The global rise in background temperatures due to climate change means the risk that an extreme heat wave will occur has increased," said Len Shaffrey, a climate scientist at the University of Reading in the UK. "For example, the probability of a heatwave such as that experienced in Europe in June 2019 was estimated to have become at least five time more likely due to climate change."

"It's just warmer than it would have been 50 years ago — this is quite logical," added Mika Rantanen, a meteorologist and Ph.D student at the Institute for Atmospheric and Earth System Research in Finland.

Image: Bob Al-GreenE / Mashable

Glaciers everywhere are dying

But before many glaciers recede beyond view in the coming decades, or die completely, there are exceptionally accessible places to see these glorious natural phenomena, which for millennia have coursed down mountains and through valleys. It's a poignant way to witness the profound scope of change now transpiring on Earth.

"Glaciers provide some of the clearest evidence of climate change that is — at least in principle — understandable for everybody: ice melts in a warming atmosphere," noted glaciologist Michael Zemp, who is the director of the World Glacier Monitoring Service.

Siberian wildfires on July 28, 2019. Image: ESA / COPERNICUS SENTINEL

Hundreds of wildfires burned in Siberia this summer, wafting dense smoke over the high northern region.

"The unusual thing about this year has been the number and distribution of fires north of the Arctic Circle in Siberia, Alaska, and more recently in Canada," said Mark Parrington, a senior scientist at the European Union's Copernicus Atmosphere Monitoring Service.

Melt ponds on Greenland's ice sheet. Image: NASA / OIB / JOHN SONNTAG

Greenland’s melting spiked in August.

The second-largest ice sheet on Earth — only surpassed by Antarctica — experienced one of its most extreme melting events on record, similar to a historic melting episode in 2012. The same record-setting mass of warm air that roasted Europe in July week settled over the Arctic region.

"It's no surprise that Greenland keeps setting records for melt and high temperatures," said Josh Willis, a NASA scientist who researches Greenland’s melting glaciers. "The entire planet is getting warmer, but the Arctic is warming faster than every place else."

Arctic sea ice. Image: GAELIN ROSENWAKS / NOAA



By early August, the most rapidly changing state in the U.S. had no sea ice within some 150 miles of its shores, according to high-resolution sea ice analysis from the National Weather Service. The big picture is clear: After an Arctic summer with well above-average temperatures, warmer seas, and a historic July heat wave, sea ice had vanished in Alaskan waters.

"Alaska waters are ice free," said Rick Thoman, a climate specialist at the Alaska Center for Climate Assessment and Policy.

Image: SHUTTERSTOCK / MOPIC

A major U.N. climate report entitled "Climate Change and Land" details that human land use now impacts over 70 percent of the ice-free land on Earth; and pasturelands make up some 37 percent of this land use. The planet's forests, rangelands, and greater vegetation, however, play a dominant role in stabilizing the Earth's climate, as land systems absorb around a quarter of human-generated carbon emissions — emissions that are presently skyrocketing.

The U.S. Revenue Cutter Thetis moored to sea ice in Alaska (1903). Image: COAST GUARD MUSEUM NORTHWESt

In the early 1900s, there was substantially more Arctic sea ice than there is today. New research used old shipping logs, meticulously kept by mariners often each hour, to extend the Arctic sea ice record back 110 years, over seven decades before satellites began regularly monitoring the high north.

Back then, sea ice showed a lot of variability, with an overall decline between 1901 through 1940. But that decline pales when compared with the Arctic's plummeting sea ice thickness and extent over the last four decades.

"There is nothing even remotely like [the last 40 years]," noted Axel Schweiger, a sea ice scientist at the University of Washington and a lead author of the research.

Okjökull glacier in 2019. Image: U.S. GEOLOGICAL SURVEY / JOSHUA STEVENS / NASA EARTH OBSERVATORY

Oddur Sigurðsson, a geologist in the Icelandic Meteorological Office, declared the largely vanished Okjökull glacier dead in 2014.

Five years later, on August 18, 2019, Sigurðsson and others hiked to the summit of the cone-shaped volcano where the glacier once thrived to leave a metal memorial in its place.

The glacier's disappearance, however, isn't unique. Glaciers are retreating all over Iceland (and, it should be noted, the world).

"The condition of the glaciers is getting poorer and poorer," Sigurðsson said.

Temperature percentiles for July over the last 140 years. Dark reds show record warmest temperatures. Image: NOAA

July 2019, marked by persistent, historic heat waves, was the warmest month ever observed in 140 years of record-keping, according to new data from the National Oceanic and Atmospheric Administration (NOAA).

"Much of the planet sweltered in unprecedented heat in July, as temperatures soared to new heights in the hottest month ever recorded," the agency wrote. "The record warmth also shrank Arctic and Antarctic sea ice to historic lows."

The McKinley Fire burns north of Anchorage on August 18, 2019. Image: MAUREEN CLARK / AP / SHUTTERSTOCK

On August 20, the most populated city in Alaska had the worst air quality in the nation, according to the World Air Quality Index.

A number of late-season wildfires perpetuated Anchorage's hazy summer, which had been the city's smokiest summer on record. Smoke levels ranked as "unhealthy," with an air quality index of 175.

Dr. Kate Marvel (left) speaking at the 2019 Social Good Summit. Image: ERIC JANKSTROM

NASA data shows the ocean's gradual, inexorable rise.

"There's a lot of things we're really sure about," NASA climate scientist Kate Marvel said at the 10th annual Social Good Summit on Sept. 22.

"We're sure sea levels are rising," emphasized Marvel, a researcher at the NASA Goddard Institute for Space Studies.

Sea ice in the Canadian Arctic Archipelago. Image: AP / SHUTTERSTOCK

After a year of extreme melt, Arctic sea ice ended up dropping to its second-lowest level on record — a mark only surpassed by melting in 2012.

On Sept. 23, the National Snow and Ice Data Center (NSIDC) announced that the Arctic's minimum sea ice extent for 2019 — meaning the smallest area of Arctic ocean covered in sea ice before cooler fall temperatures begin to rebuild the ice — was the second-lowest in the 40-year satellite era. This sea ice extent, a clear indication of a rapidly warming planet, was over 2 million square kilometers (811,000 square miles) below the average minimum extent measured in previous decades.

"The overall take-home message is that the long-term negative trend of sea-ice decline continues," said Lars Kaleschke, a physicist and sea ice expert at the Alfred Wegener Institute for Polar and Marine Research who had no role in the NSIDC report. "There is no sign of a pause or reversal of the Arctic warming trend."

Stormy waters ahead... Image: SHUTTERSTOCK / ZACARIAS PEREIRA DA MATA

The seas, which hold some 332,519,000 cubic miles of water, are warming, rising, acidifying, and losing oxygen. And a comprehensive U.N. climate special report, released Sept. 23., presents an encyclopedic review of how Earth's oceans and ice sheets have been altered as the world relentlessly warms.

Over 100 scientists from 36 nations (who cited over 6,900 studies) wrote the stark dispatch, called the "Special Report on the Ocean and Cryosphere in a Changing Climate."

Temperatures on Oct. 2. Image: CLIMATE REANALYZER / UNIVERSITY OF MAINE

Temperature records toppled, and some were smashed, over a vast region of the U.S. in early fall, including record October highs in Washington, D.C., Atlanta, Newark, Raleigh, Nashville, New Orleans, Pensacola, Indianapolis, and beyond.

Over 300 daily record highs were broken.

A firefighting helicopter pumps water during the Magic Fire.. Image: SHUTTERSTOCK / KRISTA KENNELL

On October 9, 2019, Pacific Gas and Electric started the blackouts.

The beleaguered utility, which oversees 125,000 miles of electrical and transmission lines in the fire-plagued Golden State, warned that an unprecedented 800,000 customers, meaning some 2 million Californians, could go without power for days or longer during the October power shutoff.

It's a disaster strategy to avoid, or at least limit, catastrophic, climate change-enhanced fires during the state's notoriously windy fall season. Hot, dry winds rush through mountain slopes, fan flames over the parched land, and break old, corroded electrical lines, which can light fires. Unless PG&E cuts the power first.

"If the winds pick up, watch out, out go the lights," Jeff Juliano, a disc jockey on California's KPIG radio station, mused on-air

PG&E power blackhouts. Image: JUSTIN SULLIVAN / GETTY IMAGES

José Cerca left his lab on the University of California, Berkeley campus on the evening of Oct. 9, the fateful day Pacific Gas and Electric began intentionally cutting power to wide swathes of Northern California. Cerca, an evolutionary biologist working at school's Evolab, thought his workday was finished.

But then Cerca ran into his distressed boss who said, ominously, "We have to move everything."

The news came that PG&E's intentional blackouts — a disaster strategy to limit catastrophic, climate change-enhanced fires during the state's notoriously windy fall season — would cause Berkeley's research laboratories to soon lose power. That's terrible news for biologists, many of whom freeze collections of specimens, cells, and genetic material.

"Imagine eight huge freezers with 30 years of organized research," explained Cerca, who recently joined the lab. "We have hundreds of thousands of spiders in vials organized."

Embers from the Saddleridge Fire flying around a Grenada Hills home on Oct. 11, 2019. Image: MICHAEL OWEN BAKER / AP / SHUTTERSTOCK

In what looked like a bona fide hellscape, waves of orange embers poured down a hillside and swept over Los Angeles' 210 freeway early on Oct. 10.

The footage, captured by KTLA News, is a vivid depiction of the extreme fire weather propelling flames and embers over Southern California's parched brushlands.

The video below shows an extreme, wind-driven fire event, with embers lofted into the air and carried downwind, where the sparks then ignite more flames. Called "ember spotting," it's an effective, often devastating way for wildfires to spread.

#SaddleRidgeFire Look at this embercast across the 210 freeway!!! Fire has jumped in multiple spots. Imminent life threat! pic.twitter.com/jDNjVEaldh — Anvilhead (@Anvilhead8) October 11, 2019

Michael Gollner, a fire scientist at the University of Maryland's Department of Fire Protection Engineering, said this footage is one of the most intense incidences of ember spotting he's ever seen.

Image: SHUTTERSTOCK / HARRY GREEN

To combat the terrible publicity associated with fraud allegations, brought by New York Attorney General Letitia James, the oil behemoth Exxon strategically purchased ads from Google for people searching for the climate trial. Exxon has specifically targeted keyword searches like "Exxon climate trial," "Exxon knew," and "Exxon climate change." (Mashable spotted the ads on Oct. 18 and the morning and afternoon of Oct. 22.)

Though the oil giant's scientists have understood the consequences of emitting prodigious amounts of carbon into the atmosphere since the 1950s, Exxon began to sow doubt about climate science in the 1980s. This latest Google ad campaign is a continuation of Exxon's decades-long efforts to influence the public's perception of climate change.

"You would totally expect them to do that," said John Cook, a research assistant professor at the Center for Climate Change Communication at George Mason University.

Burned land around powerlines on San Bruno Mountain. Image: JEFF CHIU/ AP / SHUTTERSTOCK

PG&E, California's largest utility, announced on Oct. 23 it would intentionally cut power to 179,000 "customers" (likely over 400,000 people) across 17 counties to avoid the possibility of sparking wildfires as notoriously potent winds threaten electrical infrastructure. Just two weeks earlier, the utility cut power to some 2 million Californians to limit the potential of rapidly moving flames.

These safety shut-offs are a novel disaster strategy intended to limit catastrophic, climate-amplified fires during the state's windy fall season. That's a significant problem because these strong, dry winds show up each year, often multiple times each fall.

"We’re getting these shutoffs during run-of-the-mill events which are not rare," emphasized Daniel Swain, a climate scientist at the National Center for Atmospheric Research.

The Kincade Fire burns near Geyserville, Calif., on Oct. 24. Image: NOAH BERGER / AP / SHUTTERSTOCK

All it takes is a spark.

California's notoriously high, dry, and hot fall winds swept through both northern and southern parts of the state in late October. Right on cue, the Kincade Fire exploded in California's wine country, Sonoma County, on Oct. 23. Some 9 hours later, the blaze had burned 10,000 acres, prompting nighttime evacuations.

Horse owners evacuate the Easy Fire amid smoky skies. Image: CHRISTIAN MONTERROSA / AP / SHUTTERSTOCK

In late October, sprawling Southern California experienced a stretch of particularly extreme fire weather, wherein a nasty confluence of powerful fall winds, profoundly dried-out land, and human development and activity (like sparks from cars or power lines) in fire country produced rapidly moving blazes.

The UN General Assembly hall. Image: SHUTTERSTOCK / DROP OF LIGHT

In April 2016, with his granddaughter sitting on his lap, Secretary of State John Kerry signed the historic Paris Agreement on Climate Change. It was a year that would soon become the warmest on record.

Although every nation on Earth is a signatory of the historic pact — which brought together all the world's countries to combat climate change — one rogue superpower has now officially started the process of withdrawing from the celebrated accord: the U.S.A.

Fulfilling President Trump's climate-denialist, anti-regulatory campaign promise, Secretary of State Mike Pompeo announced on Nov. 4 on Twitter the United States' exit from the Paris pact. This now-imminent withdrawal, however, becomes final in precisely one year — curiously, the day after the 2020 election — and can't be undone unless a different president (perhaps in 2021, 2025, or later) decides to reverse course.

Seal on Alaskan sea ice. Image: SEATOPS / IMAGEBROKER / SHUTTERSTOCK

Alaska, a rapidly changing realm, will never cease to amaze Rick Thoman, a veteran climate scientist at the Alaska Center for Climate Assessment and Policy — even after a year of broken heat records and unprecedented losses of ice.

In the deep of fall, Alaska's profound change continued. Record warm ocean temperatures mean that sea ice in the state's northern waters were at historic lows for early November. The ice refused to regrow.

"For old-timers like me, till the day I die, my jaw will drop at the sight of this stuff," Thoman said.

Taku Glacier starts thinning and retreating. Image: USGS / NASA EARTH

Chris McNeil has journeyed to Alaska's sprawling Taku Glacier at least once a year for the last decade. At 259 square miles, it's larger than Chicago. "You can see across this thing for days," said McNeil, a geophysicist at the U.S. Geological Survey.

For decades, Taku has been exceptional. Unlike most Alaskan glaciers, Taku had resisted shrinking. Between the 1940s and 1980s, Taku attracted significant scientific interest because it grew while the glaciers around it, collectively called the Juneau Icefield, thinned. By the 1990s and into the 2000s, Taku had stopped growing, and stalled. But now, glacier scientists have confirmed that even Taku — a robust glacier 4,860 feet thick — has finally started to lose mass.

"Just in the last five years we've had a number of extremely hot summers," said McNeil, the lead researcher on Taku. "The glacier has begun to thin."

The Arctic's oldest, most robust sea ice has devolved into a pathetic shell of its once-grand self.

A two-minute video from the American Geophysical Union, a leading earth sciences organization, depicts the dramatic shrinking of the toughest Arctic sea ice over the last 35 years, since 1984. (Reliable satellite observations began in the late 1970s).

An image of the Brunt Ice Shelf in July 2019 with thermal signatures. (Brunt is blue). Image: ALLISON NUSSBAUM / NASA / USGS LANDSAT

Back in February, the digital media feasted on the Brunt Ice Shelf, touting that a massive slab of ice — some two times the size of New York City — was supposedly poised to snap off into Antarctic waters.

Yet, some nine months later, Brunt had still yet to calve, or break off, the looming iceberg. The event wasn't so imminent after all — as in impending in the approaching weeks or months. But no one need worry, for the potentially 615-square-mile iceberg will indeed crack off, eventually.

"It's imminent on a glaciological time scale, how about that?" said Anna Hogg, a polar researcher specializing in satellite observations at the Institute for Atmospheric and Climate Science at the University of Leeds.

Image: Drew hamilton

Polar bears' future around Churchill, Canada looks bleak. In Churchill and the surrounding area (called the Western Hudson Bay), the bears’ population is plunging. The last two decades have been particularly harsh.

“The population has declined substantially since the late nineties by 30 percent,” said Evan Richardson, a research scientist for Environment and Climate Change Canada, a government agency. What was once a population of 1,200 bears is now 800, and falling.

Image: bob al-greene / mashable

As Earth’s mercury rises — 18 of the 19 warmest years on record have occurred since 2000 — climate change's salience has been increasingly sustained by the likes of Paul McCartney, Billie Eilish, and Neil Young.

Entrance to the U.N. in Geneva, Switzerland. Image: GETTY IMAGES / IAN TIMBERLAKE

At around 3 a.m. on Dec. 12, 2015 — essentially the very last minute — U.N. negotiators added a critical element to the historic Paris climate accords, the agreement aimed to dramatically reduce civilization's emissions of heat-trapping greenhouse gases.

This late-night addition, called "Article 6," proposes a plan for putting a price on carbon, which would make burning oil, gas, and coal increasingly expensive, and less attractive. But four years later, the U.N.'s 193 members have yet to agree on how to make this carbon-pricing scheme work.

It's a glaring piece of unfinished, ruthlessly complex business.

Image: shutterstock

Civilization's carbon emissions — like Earth's temperature, sea level, and the rate of ice sheet melting in Greenland — are still going up.

Researchers at the Center for International Climate and Environmental Research (CICERO) in Oslo, Norway spend each year tediously compiling the amount of heat-trapping greenhouse gases humanity expels into the planet's atmosphere. This year, their Global Carbon Budget Report projects that carbon dioxide emissions continued growing in 2019, though by a lower-than-usual amount of around 0.6 percent, but still reaching a new record high.

An atmospheric river douses California on Feb. 14, 2019. Image: noaa

A deluge so extreme hit Northern California in late February 2019 that a news photographer spotted a man rowing through town in a garbage dumpster.

This type of common winter storm is called an atmospheric river, a formidable band of moisture (sometimes dubbed a "river in the sky") that streams over the Pacific Ocean and into the Western U.S., often dousing California.

Atmospheric rivers can pack a damaging punch. New research published Dec. 4 in the journal Science Advances found the largest of these winter phenomena cause billion-dollar flooding disasters. And they're getting worse.

"They are becoming more intense with climate change," said Tom Corringham, a postdoctoral research economist at the Scripps Institution of Oceanography and a lead author of the study.

Half a century ago, before the first Apple computer was even sold, climate scientists started making computer-generated forecasts of how Earth would warm as carbon emissions saturated the atmosphere (the atmosphere is now brimming with carbon).

It turns out these decades-old climate models — which used math equations to predict how much greenhouse gases would heat the planet — were pretty darn accurate. Climate scientists gauged how well early models predicted Earth's relentless warming trend and published their research on Dec. 4 in the journal Geophysical Research Letters.

Most importantly, the results underscore that climate scientists were always right about how greenhouse gases like carbon dioxide trap heat and warm the surface. It was, and is, well-understood science.

"The earliest models were so skillful because the fundamental science behind the greenhouse effect and global warming is well established and fairly straightforward," said Henri Drake, a Ph.D. candidate researching ocean circulations and climate at MIT. Drake worked on this project for three years.

Polar bears outside the village of Ryrkaypiy in Russia. Image: MAXIM DYOMINOV / WWF-RUSSIA

In early December, local authorities in the Russian village of Ryrkaypiy, located on the far northeast coast of the country and bordering the Chukchi Sea, reported to the World Wildlife Fund and other organizations that 61 polar bears (up from initial observations of 56) had amassed just outside of town.

It's strange for often-solitary polar bears to congregate here, yet the iconic marine mammals have little choice: They require sea ice to hunt for seals, but the Chukchi sea ice hovered at near-record lows.

"It's exactly what we expect in these low ice years," said Geoff York, Polar Bears International’s senior director of conservation and a former biologist for the U.S. Geological Survey's Polar Bear Project.





Wildfire smoke shrouds the Opera House in Sydney, Australia on Dec. 10, 2019. Image: RICK RYCROFT / AP / SHUTTERSTOCK

Iconic Sydney, choked in bushfire smoke, was swamped in some of the most atrocious air on Earth in early to mid-December. At certain times of day, it was literally the worst.

On Dec. 9, some areas in Australia's most populated city had air pollution levels, known as the Air Quality Index (or AQI), that were a whopping 11 times that of the hazardous level, which is already the worst rating possible. On Dec. 10, Sydney remained awash in hazardous air. This is largely due to burned-up particles, broadly known as "particulate matter," saturating the air.

Anthony Wexler, an air quality researcher at the University of California at Davis, was appalled.

"The bigger story is climate change," said an exasperated Wexler, noting a growing trend in terrible air quality caused by climate-enhanced wildfires. "I mean, come on."

Oil behemoth Exxon won a big climate trial on Dec. 10.

But critically, while New York State Supreme Court judge Barry Ostrager found the company did not deceive investors about the risks posed by sinking money into future oil projects, Ostrager emphasized this doesn't excuse Exxon from its role in warming the planet.

"Climate science wasn’t on trial, and the judge acknowledged that," said Carroll Muffett, a lawyer and president of the Center for International Environmental Law.

Global temperature anamolies in November 2019. Image: NASA GISS

Some 26,000 weather stations around the planet constantly feed the National Oceanic and Atmospheric Administration (NOAA) data on land temperatures.

And separately, a fleet of ships, buoys, floats, and marine rigs take readings of the globe's sprawling oceans.

Taken together, the agency has a firm understanding of the global climate. It's warming.

2019 is a case in point. For example, so far this year (as of Dec. 16) there have been 42,487 daily high temperature records set around the world, versus 25,027 low records. Meanwhile, 364 all-time high temperatures were set in 2019, versus just 70 all-time lows. This makes sense.

"As the climate changes into a warmer climate we do expect to see more extreme warm temperatures," said Ahira Sánchez-Lugo, a NOAA climatologist. "That’s what we’re seeing, and that’s what the data are showing."

The quantity of heat the oceans have absorbed in the last decade is difficult to describe, if not imagine. The ocean's heat content is measured in the most standard unit of energy, joules (using a 100-watt lightbulb for three hours eats up 1,080,000 joules). Between 2010 and 2019, the seas absorbed roughly 110,000,000,000,000,000,000,000 joules of energy.

To help grasp this outrageous number, we'll need something big, so I've converted the ocean's heat content into nuclear bomb explosions. Specifically, explosions of the most powerful nuclear bomb ever detonated, the Tsar Bomba. In a grandiose test, the Soviets dropped this 59,525 pound, blimp-shaped behemoth in October 1961, which released some 50 megatons of energy (that's the energy produced by exploding 50 million tons of dynamite).

The conclusion: The ocean has absorbed (roughly) the equivalent amount of energy released when detonating a Tsar Bomba once every 10 minutes for 10 years.

Scales of a great white shark. Image: CLOUDS HILL IMAGING LTD / GETTY IMAGES

Shark skin is composed of hard scales, similar to microscopic teeth. But little to no research has been done on how the continually acidifying oceans — which absorb the skyrocketing carbon dioxide concentrations now amassing in the atmosphere — impact these scales, which, similar to your teeth, might corrode when exposed to carbonic acid (the result of adding carbon dioxide to water).

Though it's just one novel study with a small number of sharks, new research published Dec. 19 in the journal Scientific Reports found that shark scales on live puffadder shysharks were significantly corroded when exposed to nine weeks of acidified seawater.

"It's a bit far away from making conclusions for all sharks," said Lutz Auerswald, a biologist at Stellenbosch University in South Africa and an author of the research. But, he added, it's logical this scale corrosion could happen to other shark species. After all, acidified oceans eat away at the calcium shells in diverse marine critters.

The Gospers Mountain Fire burns property at Bilpin, in the Blue Mountains. Image: DAN HIMBRECHTS / EPA-EFE / SHUTTERSTOCK

Back in early November, David Bowman had a bad feeling about Australia's thriving wildfires.

The ingredients for bushfire hell had come together. The forests were exceptionally dry. There was no hint of meaningful rain. Winds howled through the country. And it was getting hotter. Eventually, Australia broke its record for its hottest day ever — two days in a row.

"I said 'this is unprecedented'," recalled Bowman, a professor of pyrogeography and fire science at the University of Tasmania. "The whole system was set up to burn."

It has.

Fires have burned over three million acres of Eastern Australia bushland, including the 1.2-million-acre Gospers Mountain megafire northwest of Sydney, labeled "out of control" by the region's fire agency, the New South Wales (NSW) Rural Fire Service. That's nearly the size of Grand Canyon National Park, and larger than Rhode Island. The Syndey Morning Herald called Gospers a "monster" fire, and notes it's now the largest forest fire to start from a single ignition point in Australian history (there have been larger grass fires).

This post was originally published on March 15, 2019, and has been updated multiple times since then. Most recently, to close out the year, we added items 62 to 99 and republished the post on Dec. 24, 2019.