Federal scientists have once again contradicted the White House, this time in a major new climate change assessment that was inauspiciously rushed to release the Friday after Thanksgiving. Their findings, however, should give even the Trump administration pause: Global warming could cause more harm to the US economy by 2100 than even the Great Recession did.

And the risks aren’t just down the road. The 1,600-page report directly connects climate change to ongoing issues like declining water levels in the Colorado River Basin and the spread of ticks carrying Lyme disease, phenomena that are currently costing Americans resources and lives.

“The impacts and costs of climate change are already being felt in the United States, and changes in the likelihood or severity of some recent extreme weather events can now be attributed with increasingly higher confidence to human-caused warming,” according to the new report, the second volume of the fourth National Climate Assessment.

The cost of doing nothing.



Annual economic losses in the USA due to climate change in 2090 according to the 4th National Climate Assessment (in 2015 $):



Moderate warming (RCP 4.5): $280 billion/yr

Extreme warming (RCP 8.5): $500 billion/yr#ClimateFriday #NCA4 pic.twitter.com/ncMj2vGDLS — Robert Rohde (@RARohde) November 23, 2018

The assessment comes from the US Global Change Research Program, a consortium of 13 federal agencies including the Department of Defense, the Environmental Protection Agency, and NASA. It’s required by law and the latest report is the second installment of the fourth assessment.

That’s why a White House that is in denial about climate change has to continue publishing reports that say otherwise. Even when confronted with California’s deadliest wildfire on record, a disaster fueled in part by rising average temperatures, members of President Donald Trump’s administration — including Trump himself — have chosen instead to blame environmentalists rather than acknowledge climate change.

Brutal and Extended Cold Blast could shatter ALL RECORDS - Whatever happened to Global Warming? — Donald J. Trump (@realDonaldTrump) November 22, 2018

The first volume of the assessment was released about a year ago, highlighting the science of how global climate change is rippling throughout the US. Nothing in the latest volume is particularly surprising, but it includes new research that more directly highlights humanity’s role in extreme weather events and measures how future changes will play out at smaller scales, like cities.

The National Climate Assessment is more limited in scope than the October report from the United Nations’ Intergovernmental Panel on Climate Change that explored what it would take for the world to limit global warming to 1.5 degrees Celsius above pre-industrial levels. But the latest report echoes the same basic themes about climate change:

It’s already happening It’s going to get worse. It’s going to cost us dearly. We can still do something about it.

What was surprising about the latest installment of the National Climate Assessment was that it was rushed to release — surprising even many of the 300 scientists who contributed to it, as Robinson Meyer reported in the Atlantic:

John Bruno, an author of the report and a coral biologist at the University of North Carolina, told me that he only learned last Friday that the report would be released today. “There was no explanation or justification,” he said. “The [assessment] leadership implied the timing was being dictated by another entity, but did not say who that was.”

Originally, the report’s release was scheduled to coincide with the American Geophysical Union’s December meeting in Washington, DC, a major gathering of scientists. It’s not clear why it was rushed out this week instead, but many scientists and observers saw it as an attempt to bury the findings.

A White House spokesperson downplayed the report’s significance, telling the BBC that it was “largely based on the most extreme scenario, which contradicts long-established trends by assuming that ... there would be limited technology and innovation, and a rapidly expanding population.”

I wrote the climate scenarios chapter myself so I can confirm it considers ALL scenarios, from those where we go carbon negative before end of century to those where carbon emissions continue to rise. What WH says is demonstrably false. https://t.co/aTkrBNh9IL — Katharine Hayhoe (@KHayhoe) November 24, 2018

Here are three key takeaways from the report.

1) Climate change is expensive

By the end of the century, warming on our current trajectory would cost the US economy upward of $500 billion a year in crop damage, lost labor, and extreme weather damages. This is almost double the economic blow of the Great Recession in the early 2000s.

“With continued growth in emissions at historic rates, annual losses in some economic sectors are projected to reach hundreds of billions of dollars by the end of the century —more than the current gross domestic product (GDP) of many U.S. states,” according to the report.

There are also second-order costs to contend with. Rising temperatures, for instance, make power generation more inefficient, raising the costs of electricity.

No region of the country is immune to these costs. From fisheries to agriculture to tourism, major sectors of the economy stand to be damaged by climate change.

This echoes findings from earlier this year that the US faces some of the highest social costs of carbon dioxide in the world. But it also implies that the inverse is true: Fighting climate change has huge financial benefits. Cutting greenhouse gases makes sense simply for our own economic self-interest.

2) Climate change is deadly

Rising temperatures kill — in any number of indirect ways, the report notes, but literally, too.

The most direct way they do so is by increasing the frequency, intensity, and duration of heat waves; this summer alone, we saw deadly temperature spikes in Japan, Canada, and Pakistan that killed dozens of people.

In the US, this heat is expected to more than offset any lives saved from warmer winters. “With continued warming, cold-related deaths are projected to decrease and heat-related deaths are projected to increase; in most regions, increases in heat-related deaths are expected to outpace reductions in cold-related deaths,” according to the report.

Other maladies are also projected to get worse as the climate changes. Mosquitoes that spread viruses like West Nile and Zika are seeing their ranges grow. The ticks that spread Lyme disease are moving northward. Pollen-spewing plants are making allergy seasons longer and ever more severe as warmer winters and higher carbon dioxide levels make them more active.

The scientists in the report projected that air quality will suffer as well. The pollution we breathe in is already one of the biggest killers in the world, taking years off of people’s lives. Rising average temperatures worsen ground-level ozone, which can harm breathing. It can also exacerbate sources of pollution like wildfires, which have created some of the worst breathing conditions in the world this month in California.

On the heels of our worst air quality episode in recent memory, a key message in the National Climate Assessment is the further degradation of #airquality from increasingly frequent & severe wildfires driven by #climatechange. https://t.co/SODGVp6w3t #ClimateFriday #CAfire pic.twitter.com/IAv5sjibtV — Daniel Alrick (@SFmeteorologist) November 23, 2018

3) We can still do something to limit global warming and counter its effects

We already have most of the tools we need to aggressively curb carbon dioxide emissions, thereby limiting the rise in global average temperatures. According to the report’s scientists, we must use them.

“Future impacts and risks from climate change are directly tied to decisions made in the present,” the assessment reads.

These tactics range from shifting to cleaner energy, to changing how we use land, to pulling carbon dioxide out of the air. The question is whether there is enough political will to deploy these methods on a meaningful scale.

The climate crisis threatens both our communities & our economy. While @realDonaldTrump ignores his own admin’s report, House Dems are pushing for action w/ select committee on #ClimateChange. We can create millions of good-paying jobs w/ bold, green infrastructure investments! — Nancy Pelosi (@NancyPelosi) November 24, 2018

At the same time, a certain amount of warming is unavoidable, so we will still have to adapt to higher temperatures, higher sea levels, and more extreme weather. “Adaptation and mitigation policies and programs that help individuals, communities, and states prepare for the risks of a changing climate reduce the number of injuries, illnesses, and deaths from climate-related health outcomes,” according to the assessment.

The biggest uncertainty in climate forecasting is always us: What will humanity actually do about climate change?

That’s a question that even 13 federal agencies and 300 scientists can’t answer. But the world’s nations are trying. The United Nations is now preparing to meet in Katowice, Poland, next month to discuss putting the Paris climate agreement into action, a goal complicated by the fact that one of the world’s largest emitters, the United States, wants out of the accord.