On Friday, the Trump administration published a new report on climate change. Clocking in at 470 pages, it’s a definitive synthesis of the latest in climate science that’s been written and peer-reviewed by hundreds of scientists and even the general public.
The report will underpin the National Climate Assessment, the fourth installment in a running series of reports on climate change in the U.S. mandated by the Global Change Research Act of 1990.
By releasing it, the Trump administration basically kicked itself in the dick. Trump and his cabinet members and political appointees have a veritable rainbow of climate science denial views. Now the administration has put out a definitive report showing how wrongheaded those views are.
Let’s take a look.
Hackneyed but true, there really is a Trump tweet for everything—and there are 115 of them when it comes to climate change. This one, though, is the one that keeps giving for its sheer ignorance and stupidity.
Straight from the executive summary to the executive branch, here’s what the scientists say.
“This assessment concludes, based on extensive evidence, that it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.”
I also searched the entire document for the word ‘Chinese’ just to be sure I wasn’t missing anything.
Where to even start with this guy? He’s deleted the EPA’s climate change website, appointed *smog* deniers to the science advisory board, and moved to overturn climate regulations. But perhaps nothing encapsulates Pruitt unplugged more than his March interview with CNBC’s Squawkbox when he dropped this gem:
“I would not agree that it’s [CO2] a primary contributor to the global warming that we see.”
Let’s turn to Chapter 2: Physical Drivers of Climate Change. There, there’s this very ugly but highly informative graph:
What it shows is how all kinds of gases from human activities affect the climate and in orange, their sum impact. And wouldn’t you know, human carbon dioxide emissions are the single biggest contributor to changes in radiative forcing, a measure of how much extra energy the planet retains.
Here’s another way of looking at it, which shows that carbon dioxide is indeed far and away the primary contributor to global warming:
Thursday became a big day for Rick Perry, when he made the case for fossil fuels being the key to solving sexual assault at an Axios event.
During that same event, he also made some comments on climate science that flew under the radar. Here’s Axios reporting on Perry’s appearance: “‘I still think the science is out on’ whether humans cause 100 percent of it.”
For those of you keeping track at home, please turn your books to Chapter 3, Key Finding 1:
The likely range of the human contribution to the global mean temperature increase over the period 1951–2010 is 1.1° to 1.4°F (0.6° to 0.8°C), and the central estimate of the observed warming of 1.2°F (0.65°C) lies within this range (high confidence). This translates to a likely human contribution of 93%–123% of the observed 1951–2010 change
A charitable interpretation of Perry’s comments would say he’s deeply immersed in discussions of scientific uncertainty and radiative forcing. It’s possible he may subscribe to a more constrained radiative forcing measure of watts per square meter, falling in the camp that says humans are only responsible for 93% of the warming.
A less charitable interpretation might be that the guy who also said in June that “most likely the primary control knob [for climate] is the ocean waters and this environment that we live in” is not that bright and just trying to stir shit up.
Zinke hails from Montana, home to the stunning Glacier National Park. Those glaciers are melting, and Zinke has said he’s seen that with his own eyes and thinks humans are playing a role in climate change. That’s good because he’s right (it is also bad for glaciers and ecosystems that depend on them).
But that hasn’t stopped him from obfuscating about climate. At a June budget hearing, Zinke threw down with Rep. Betty McCollum (D-Minn.). After invoking those glaciers to show his bonafides, Zinke said “CO2 is a concern. But what can we do about it? What should we do about it? What is the right path forward?”
Well, for starters we should cut carbon emissions stat to avoid the worst effects of climate change. That’s why there’s a whole chapter on the topic dubbed “Perspectives on Climate Change Mitigation.”
It’s even got a great graph showing how curbing global emissions affects the odds of preventing dangerous levels of global warming (Figure 14-3 if you’re still following along).
If those efforts fail, then Zinke may want to check section 14.3, which outlines more risky options if the world nears dangerous levels of warming.
“There is increased interest by some scientists and policy makers in exploring additional measures designed to reduce net radiative forcing through other, as yet untested actions, which are often referred to as geoengineering or climate intervention actions.”
Risky, to be sure, but something policymakers like Zinke need to understand to know what all our options are.
Late Friday afternoon, the White House released a statement on the report itself:
“The climate has changed and is always changing” is the oldest denier trope in the book. Someone please make this nightmare end.
The White House also decided to cherrypick a line from the report about uncertainty in Chapter 1. Let’s take a look at the full quote in context:
“Global climate is projected to continue to change over this century and beyond. The magnitude of climate change beyond the next few decades will depend primarily on the amount of greenhouse (heat-trapping) gases emitted globally and on the remaining uncertainty in the sensitivity of Earth’s climate to those emissions (very high confidence). With significant reductions in the emissions of greenhouse gases, the global annually averaged temperature rise could be limited to 3.6°F (2°C) or less. Without major reductions in these emissions, the increase in annual average global temperatures relative to preindustrial times could reach 9°F (5°C) or more by the end of this century (high confidence).”
While the White House would like you to believe there’s uncertainty about the impact of greenhouse gases on the climate, the biggest source of uncertainty is actually us and when we start to reduce emissions. And we had better get started soon.