To President Trump, science is fake news. Worse, it can’t be intimidated, bullied, or bought off. You can’t grab physics by the pussy or sic your lawyers on it. On climate and public health issues, Trump and his cronies have proven their hostility to science over and over again: They’ve approved the use of chemicals proven to cause brain damage in children, loosened air pollution regulations that save lives, and promoted the consumption of fossil fuels, which scientists have known for decades is the warming up our planet and putting the future of civilization itself at risk.
So it’s no surprise, really, that Trump administration officials didn’t get in the way of the release of a new climate report last week, despite the fact that it underscored just how hypocritical and downright medieval the administration’s science-denying climate policies really are. But Trump and climate-denying agency heads like EPA Administrator Scott Pruitt are so cocky in their utter disregard for science that they can’t even bother to fake it anymore.
The release of the report was not unexpected, nor are its contents a big surprise (a draft had been leaked earlier this year). The report is part of the National Climate Assessment, a congressionally mandated review that comes out every four years (the last one was published in 2014). The portion of the assessment that was officially released last week was an update on the latest climate science. A second part of the assessment, a report on the impacts of climate change in the U.S. was released in draft form (after public comment, as well as review by experts at the National Academy of Sciences, Engineering, and Medicine, a final version will climate impact report be published in December 2018).
You might think, “Another climate report?” Yawn. The world is drowning in climate reports, data, charts, graphs. But this one is different. For one thing, it’s a kick-ass analysis that is specifically focused on the U.S., one that refines and clarifies decades of climate science and distills it into easy-to-understand language that neither sugarcoats nor exaggerates the risks we face.
Like previous climate assessments, this one is very clear about the basics: Over the past 115 years global average temperatures have increased 1.8 degrees Fahrenheit, leading to record-breaking weather events and temperature extremes. The long-term warming trend is “unambiguous,” the report argues, and there is “no convincing alternative explanation” that anything other than you and me and our fellow seven billion humans on the planet – as well as the vehicles we drive, the coal and gas plants we operate, the forests we destroy – are to blame for it. The report points out that weather catastrophes from floods to hurricanes to heat waves have cost the United States $1.1 trillion since 1980, and makes plain that those cost will rise dramatically in the future.
The real art of the report is in the details, and in the way it refines our understanding of key issues that have huge implications for how we live today and in the future.
Here are a few highlights:
Sea level rise is happening fast, and it’s scarier than you think. The world’s oceans could rise by as much as 8 feet by 2100.
“Emerging science regarding Antarctic ice sheet stability suggests that, for high emission scenarios, a [global mean sea level rise] exceeding 8 feet (2.4 m) by 2100 is physically possible, although the probability of such an extreme outcome cannot currently be assessed.”
Sea level rise has major social justice implications.
“As shown [in the Tampa Bay region], 96% of the area inhabited by the high-vulnerability population is likely to be abandoned as opposed to 54% of the area inhabited by the low-vulnerability population.”
The relationship between rising CO2 levels and drought is not simple.
“Recent droughts and associated heat waves have reached record intensity in some regions of the United States; however, by geographical scale and duration, the Dust Bowl era of the 1930s remains the benchmark drought and extreme heat event in the historical record (very high confidence). While by some measures drought has decreased over much of the continental United States in association with long-term increases in precipitation, neither the precipitation increases nor inferred drought decreases have been confidently attributed to anthropogenic forcing.”
Expect more wildfires in Alaska and the West.
“The incidence of large forest fires in the western United States and Alaska has increased since the early 1980s (high confidence) and is projected to further increase in those regions as the climate warms, with profound changes to certain ecosystems (medium confidence).”
Climate tipping points are real, and if we push the climate system too hard, we have no idea what kind chaos we might unleash.
“Positive feedbacks (self-reinforcing cycles) within the climate system have the potential to accelerate human-induced climate change and even shift the Earth’s climate system, in part or in whole, into new states that are very different from those experienced in the recent past.”
Despite what deniers and skeptics may say, climate models are likely to understate climate risks, not overstate them.
“While climate models incorporate important climate processes that can be well quantified, they do not include all of the processes that can contribute to feedbacks, compound extreme events, and abrupt and/or irreversible changes. For this reason, future changes outside the range projected by climate models cannot be ruled out…Moreover, the systematic tendency of climate models to underestimate temperature change during warm paleoclimates suggests that climate models are more likely to underestimate than to overestimate the amount of long-term future change.”
To avoid the worst impacts of climate change, we have 20 years to get our shit together and dramatically cut CO2 emissions.
“Given estimated cumulative emissions since 1870, no more than approximately 230 gigatons of carbon may be emitted in the future to remain under this temperature threshold. Assuming global emissions are equal to or greater than those consistent with the RCP4.5 scenario, this cumulative carbon threshold would be exceeded in approximately two decades.”
There’s lots more in the 600-page report, which I urge you to read for yourself. It’s dark stuff, but it’s also strangely inspiring. The report demonstrates that even in these dark days, when Washington DC is shrouded in denial and corruption, scientists are continuing to do their work, extending our understanding of our world and the risks we face. In times like these, that’s a real cause for hope.