Extreme Temperature Diary- Saturday November 19th, 2022/ Main Topic: Underestimating Arctic Warming

The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of recently reported ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉

Main Topic: Underestimating Arctic Warming

Dear Diary. As the climate crisis deepens it’s only humanly natural that there will be more finger pointing. Plenty of mistakes have been made since about 1980, when there was enough consensus among experts to guide policy makers towards a green sustainable future, with a rather smooth transition relative to what needs to happen in 2022. Now that transition will need to be fast with some great discomfort felt by all if we are to meet goals with a deadline around the year 2030. Denial of a dark future of harsh conditions due to the continued burning of fossil fuels was a predictable outcome looking at human psychology. It’s not that surprising that some of this denial extended to scientists making forecasts over the last several decades.

Some individual scientists were well aware of the old proverbial let’s not shoot the messenger syndrome. In order to be believed and not appear to be too alarmist, some forecasts, and in particular those in association with the Arctic, apparently were modified a bit. We see this play out from the following Scientific American article in which some climatologists did indeed tamp down their predictions, whether intentional or not, issuing forecasts at the lower range of probable outcomes. From now on it’s imperative that forecasters dish out their best guidance, even if it is extremely bad news, in order for policy makers to do what is necessary for all of our sakes to make future people as happy and prosperous as possible:

Why Scientists Got the Fast Pace of Arctic Warming Wrong – Scientific American

Why Scientists Got the Fast Pace of Arctic Warming Wrong

Concerns about accusations of hype may have biased them toward conservative underestimates

Why Scientists Got the Fast Pace of Arctic Warming Wrong
Credit: Jay Bendt

Climate scientists have a surprising habit: They often underplay the climate threat. In 2007 a team led by Stefan Rahmstorf compared actual observations with projections made by theoretical models for three key climate variables: atmospheric carbon dioxide, global average temperature and sea-level rise. While the projections got CO2 levels right, they were low for real temperature and sea-level rise. In 2008 Roger Pielke, Jr., found that sea-level rise was greater than forecast in two of three prior Intergovernmental Panel on Climate Change reports. In 2009 a review of hundreds of papers on climate change identified several areas where scientists had lowballed event predictions but none in which they had overestimated them.

In 2013 researcher Keynyn Brysse, then at the University of California, San Diego, along with other colleagues and me, pointed out that these underestimates represent a kind of bias. Scientists tended toward lower projections because they did not want to be accused of making dramatic and exaggerated claims. The articles reporting the underestimates have been widely cited, so one might think that by now scientists would have taken corrective steps.

But recent studies of Arctic warming suggest that the problem may not have gone away. For instance, scientists have long known about how Arctic ice reflects sunlight, redirecting heat away from the planet. But as polar ice melts because of global warming, the Arctic Ocean absorbs more heat, which causes the Arctic to warm even more, which melts more ice, and so on. It should surprise no one, then, that the area is warming fast. Yet scientists have been caught off-guard by just how fast the region is heating up.

A recent study led by Mika Rantanen of the Finnish Meteorological Institute found that, since 1979, the Arctic has warmed nearly four times faster than Earth as a whole. Few climate models have predicted an effect this large.

Model results are typically reported as the averages of many runs of a set of similar models, referred to as ensembles. These new Arctic temperature observations are not only warmer than all the major ensemble averages but, in some cases, outside the whole ensemble envelope. In one very large and highly respected one—the Max Planck Institute Grand Ensemble—the observed warming for 1979–2021 is entirely beyond the results. Some real-world observations are hotter than even the hottest projections.

This has several implications. First, it reminds us that averages can be misleading. Extreme outcomes may be unlikely but do occur and are crucial in assessing risk. Second, it suggests that climate models may be continuing to underestimate key climate effects.

Admittedly, the observations might be wrong; measuring the temperature of the region is notoriously difficult, in part because of sparse sensor coverage over the Arctic Ocean. In addition, scientists may have analyzed different time periods or used conflicting definitions of “Arctic” boundaries. But it may also be that their subconscious bias toward playing things down was playing itself up.

We’ve heard a lot in recent years about subconscious bias in relation to race and gender discrimination. But subconscious bias can be caused by many things, including defensiveness. Even now scientists continue to be accused of exaggerating climate risks by prominent figures who get outsized media attention. Scientists who have internalized this concern may be subconsciously biasing their models to be unrealistically conservative.

If scientists have underestimated Arctic warming, they have likely minimized amounts of permafrost melting and methane release as well. And that could be truly dire because the permafrost holds about 1.5 billion metric tons of organic carbon, twice as much as now in the atmosphere. Were that carbon to be rapidly released, it could cause a worst-case scenario: a runaway greenhouse effect. Whatever the cause, it’s time that scientists looked seriously at whether their models continue to underplay critical aspects of the climate problem. Low estimates can create the false impression that we have more time to fix the problem than we actually do.

This article was originally published with the title “Downplaying the Pace of Arctic Warming” in Scientific American 327, 5, 86 (November 2022)




Naomi Oreskes is a professor of the history of science at Harvard University. She is author of Why Trust Science? (Princeton University Press, 2019) and co-author of Discerning Experts (University of Chicago, 2019). Credit: Nick Higgins

Recent Articles by Naomi Oreskes

Here are some “ET’s” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks + heavy precipitation reports:

Here is more October climatology:

Here is more climate and weather news from Saturday:

(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)

If you like these posts and my work please contribute via the PayPal widget, which has recently been added to this site. Thanks in advance for any support.) 

Guy Walton… “The Climate Guy”

Leave a Reply

Your email address will not be published. Required fields are marked *