The climate crisis is already here — and it's only getting worse.

Kacper Pempel / Reuters Smoke and steam billows from Belchatów Power Station, Europe's largest coal-fired power plant, operated by PGE Group, at night near Belchatow, Poland.

Tap to play or pause GIF Tap to play or pause GIF Peter Aldhous / BuzzFeed News / Via esrl.noaa.gov The 2010s (red in all charts) were when the atmospheric concentration of carbon dioxide broke through the "400 parts per million" threshold. The thin wavy line shows observed global monthly average measurements, which fluctuate with the seasons; the thicker line is the smoothed trend.

Continuing a trend that was first recorded in the 20th century, the atmospheric levels of carbon dioxide — a potent heat-trapping or “greenhouse” gas — grew every year this decade. And they didn’t just go up at a steady rate, they went up at a faster and faster clip. In fact, CO2 levels are now rising at a faster pace than ever before. “This is the fastest it’s ever been,” Pieter Tans, chief of NOAA’s carbon cycle greenhouse gases group, told BuzzFeed News. In 2015, CO2 levels passed the symbolic 400-parts-per-million threshold. The last time this happened, humans did not exist and the planet was even warmer than it was today. This time around, scientists have concluded that it's humans, not nature, who are responsible for the unprecedented rise. CO2 levels hit 407.8 ppm in 2018, according to the World Meteorological Organization. Carbon dioxide can linger in the atmosphere for hundreds of years, and in the ocean for even longer. 2. Temperatures Kept Going Up

Tap to play or pause GIF Tap to play or pause GIF Peter Aldhous / BuzzFeed News The global average temperature for each month, with a separate line for each year, plotted as the difference from the 20th century's global average for each month.

The decade kicked off in 2010 with what was then the hottest year on record. That record was then broken again in 2014, and then shattered in 2015 and 2016. Then July 2019 served us the hottest month on record. As 2019 draws to a close, scientists have concluded that the back half of this decade was the warmest five-year stretch in recorded history. And it was in this decade that we officially warmed more than 1 degree Celsius above preindustrial levels. This means we’re already more than halfway to the temperature goals set by the Paris climate agreement, which aimed to limit warming to 1.5 to 2 degrees Celsius. 3. Arctic Sea Ice Disappeared

Tap to play or pause GIF Tap to play or pause GIF Peter Aldhous / BuzzFeed News / Via nsidc.org The minimum area of sea ice in the Arctic, averaged over a five-day period, in each year. The inset map shows the median extent of sea ice in September, the month in which the yearly minimum occurs.

As the planet has heated, Arctic sea ice has declined. The lowest levels of Arctic sea ice were recorded in 2012, and 2019 has tied for the second-lowest levels. “Each succeeding decade is lower,” Walt Meier, senior research scientist at the National Snow and Ice Data Center, told BuzzFeed News. “That’s clearly a declining trend.” Beyond the sea ice extent, Meier mentioned another worrying trend linked to the changing climate: Satellite imagery has revealed Arctic sea ice has been getting thinner as the thicker, older ice has melted. The big question for Meier and other scientists watching the Arctic is when we will experience our first ice-free summer. “It’s no longer a matter of if, it’s when — at least in current trajectory we’re going on,” Meier said. 4. The Seas Kept Rising

Allison Joyce / Getty Images Water floods a street in lower Manhattan in 2012 after Hurricane Sandy, which killed at least 233 people in the Caribbean and North America and caused massive flooding across much of the Atlantic seaboard.

Sea levels are rising, thanks to both melting ice and the expansion of warm ocean water. Global sea levels have risen about 3 inches since 1993, when the satellite record began. And those levels are rising faster and faster, affecting some parts of the world more drastically, according to the 2019 Intergovernmental Panel on Climate Change’s special report on oceans. While 3 inches may not seem like much, the rise has led to increased coastal flooding from storms like Superstorm Sandy and more frequent high tide or “sunny day” flooding in places like Florida. One US-focused study found 17 states lost almost $16 billion in coastal property damage from 2005 to 2017 due to tidal flooding exacerbated by rising seas. In the Pacific Ocean, multiple islands have already shrunk or disappeared entirely. 5. Coral Reefs Died Across the World

Lucas Jackson / Reuters Pictures A bleaching event affecting an entire field of boulder star corals off the coast of St Thomas in the US Virgin Islands in 2019.

The worst coral bleaching event in recorded history lasted from 2014 to 2017, damaging reefs across the globe. The event “affected more reefs than any previous global bleaching event," according to a Coral Reef Watch report, and it was especially bad in places like the Great Barrier Reef, Kiribati, and Jarvis Island. Only two other global events had struck corals previously, in 1998 and 2010. For coral reef expert Kim Cobb of Georgia Institute of Technology, “2016 jumps off the page.” That was the year she arrived at the Kiritimati coral reefs, her longtime research site, to find a lot of dead coral. The Great Barrier Reef, the world’s largest and longest coral reef, lost about half its coral following unrelenting warm waters in 2016 and 2017. 6. Disasters Got Even More Disastrous

Tap to play or pause GIF Tap to play or pause GIF Peter Aldhous / BuzzFeed News / Via ncdc.noaa.gov Weather and climate disasters that caused more than $1 billion in damage across the US, corrected for inflation to 2019 dollars. Storms include winter storms, tropical cyclones, and other severe storms; other disasters include wildfires, droughts, freezing weather, and river flooding.