Wednesday's postcard, and coping with the surreal nature of climate change, and humans...

September 27, 2023

Black-headed grosbeak, out on a charred limb, west of Spokane

Regarding Science, Climate Change, and Witch Burning…

The scientific prognosis of global warming hasn’t changed since NASA physicist James Hansen delivered his epochal testimony to the U.S. Senate thirty-five years ago.

“Global Warming Has Begun, Expert Tells Senate,” read the headline in the next day’s New York Times.

Hansen’s warning was especially sobering for the United States which, as a nation, is at the top of the list of historic greenhouse gas emissions, accounting for 25% of cumulative carbon dioxide (CO2) emissions since the mid-18 century. (The next largest is China, at just below 13%). To say this was unwelcome news puts it mildly, and the ensuing evidence has validated Hansen’s assessment.

As is true with other important scientific advances, there are uncertainties that orbit around a core of settled truths. The central, settled truths about climate change are:

•CO2 in the atmosphere causes the planet to absorb heat that would otherwise radiate into space. This is commonly referred to as the “greenhouse” effect.

•Human-generated (anthropogenic) CO2 emissions from the combustion of fossil fuels are intensifying the “greenhouse” effect to an extent that it already threatens a myriad of plant and animal species with extinction and, at a minimum, portends famine, dislocation and other major hardships for humans.

It is regularly alleged that anthropogenic climate change is a “hoax.” It’s not. The steady escalation of atmospheric CO2 is illustrated in the two graphs, below, which show (1) the increases in atmospheric CO2 measured in the past 65 years (from direct atmospheric measurement) and (2) the trend over the past 10,000 years, adding data from ice core measurements.

Among the bad faith arguments from climate change deniers is that CO2 is “plant food,” and thus a good thing. Of course, water is a good thing too, unless you’re drowning in it. Another element of the con game is to point to periods—sometimes several years in duration—where global temperatures remain relatively stable even as CO2 emissions go up. The suggestion is that if there’s not a tight temporal fit between CO2 levels and global temperature rise then climate change is illusory. This purposefully ignores the other natural and unnatural variables that effect surface and atmospheric temperatures from year-to-year, even though the long term correlation with steadily rising CO2 levels is clear. The chart below, compiled by the U.S. Environmental Protection Agency, illustrates the overall, long-term trend toward global warming over a 120 year period.

There were always reasons to think we might be up for this challenge. By “we” I mean us, the people in the world’s bellwether democracy, the home to MIT, Cal-Tech, 17 national laboratories, and people who can invent and build all sorts of things including the seemingly miraculous James Webb telescope. Americans have garnered enough Nobel prizes to hand one to everybody in the town of LaCrosse, Washington, (pop. 313) with nearly 100 left over to share with the nearby town of Endicott.

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