It’s odd that 538 only accepts comments from people with Facebook accounts, despite being associated with ABCNews, which has its own user accounting system. I’m commenting here instead #fivethirtyeight.

Anyway, per this post, a recent article and podcast at 538 demonstrates there is a poor understanding regarding global warming, climate change, its consequences, and these assessments, even by educated Democrats. Taking the last first, the latest National Climate Assessment is the 4th, and it’s authorized and required by an act of Congress, once every 4 years. However, there are basically two volumes produced, an updated assessment of climate science, and, then, in the next year, an updated assessment of impacts. These reports are hardly produced in isolation: In addition to being compiled and written by a large team of scientists, they are each independently reviewed by the National Academies of Science, Medicine, and Engineering. Moreover, there is a comment period where the public can comment on the reports. Comments by the Academies and by the public are addressed by the team from the U.S. Global Change Program producing the reports and these are available at the site.

All that said, there is also a misunderstanding about the scope of climate change. CO2 is not like most other pollutants in that it has a very long life. That means it accumulates, and, not only is the USA a major producer of CO2, it owns a substantial chunk of the accumulated emissions. Moreover, because of CO2’s long life and other physical aspects, such as 90% of the excess heat going into oceans, the trouble is that if we collectively stop emitting, we’ll keep damage and change from getting worse, but it won’t reverse, not for at least centuries. Moreover, there is a lag between the forcings and causes of additional energy and manifestations as effects. This is a very system, and, if we stop, it will keep getting worse for a decade or more. Some systems on Earth, like ice sheets, respond even more slowly. It’s agreed by many glaciologists, for example, that the West Antarctic Ice Sheet (WAIS) is doomed to collapse, even if that will take a couple of centuries to be realized.

To the comment that why is warming bad, the historical record which, by now, is much better established than it was for NCA2 or even NCA3, shows humanity has never lived in a time when temperatures overall were this extreme. It isn’t just temperature, it’s energy available to weather systems and moisture aloft that matters, not to mention things like loss of ice.

(Hat tip to The Economist which reprinted the graph from The Lancet.)

Also, because of temperatures and oceanic acidification, while primary productivity of oceans and forests may increase for a time, ultimately these will be limited and reverse. Experiments show that plants get used to having an abundance of CO2 and aren’t as effective sinks. There are some controlled experiments which even suggest forests and plantings could be net CO2 sources, if plant respiration exceeds rate of CO2 consumption. A lot depends upon the microbial mix in soils where plants grow, and this is sensitive to temperature, CO2 concentration in atmosphere, and available moisture. For example, arid conditions aren’t conducive to CO2 take-up. It is believed, too, that enhanced growth is limited by available Nitrogen.

And there are other impacts as well anticipate by the science, such as changes in oceanic circulation, which could have major consequences for regional weather and distribution of moisture. The trouble with these kinds of perturbations is that they are beyond direct experience by people, even if there is really solid evidence they’ve happened before.

I think the posture of the present administration that the NCA is a report produced by some fringe group really is at odds with the process and its depth. It hardly is a surprise. It’s produced on a regular schedule. It’s possible for anyone to engage with it. And the emergent understanding available on climate change and global warming is breathtaking in depth as well as breadth: It’s understood by ecologists and biologists as well as geophysicists. Even doctors and epidemiologists are seeing its effects.

FiveThirtyEight‘s political podcast on this report missed a lot of these aspects. In that respect, their journalism was disappointing here.

By the way, to the claim of 45 that the United States is among the cleanest of countries on emissions, it just ain’t:

And, since cumulative emissions are what matter, the United States has a lot it’s responsible for:

But this doesn’t prevent 45 or Forbes, for that matter, pointing their fingers elsewhere: