Scivillage.com Casual Discussion Science Forum

https://rogerpielkejr.substack.com/p/the...te-reality

INTRO: Last week John Kerry, the U.S. Special Presidential Envoy for Climate, said in a speech at the New York Climate Summit:

“We're currently heading towards something like 2.4 degrees, 2.5 degrees of warming on the planet”

Let’s compare that to what Kerry said in another speech almost exactly 2 years before, in September 2021:

“Currently, as we’re talking today, we are regrettably on course to hit somewhere between 3, 4 degrees at the current rate.”

Kerry’s latest views on projected global temperature change has no doubt been informed by the latest net-zero assessment of the International Energy Agency, released to the public yesterday, which projects a median warming in 2100 under “stated policies” of ~2.4 degrees Celsius as you can see in the figure below.

Kerry’s large change in outlook — from 4C to 2.5C or less — will come as no surprise to readers here, as for years I’ve been talking about the incredible shift in expectations for the future. Despite the growing recognition that our collective views of the future have changed quickly and dramatically, this change in perspective — a positive and encouraging one at that — has yet to feature in policy, media or scientific discussions of climate.

That silence can’t last, as reality is persistent... (MORE - details)

Looking at the graph of global temperature change here:
https://www.climate.gov/news-features/un...emperature
We see it is noisy - part a real effect and (probably) part that we don't have temperature sensors absolutely everywhere.

Depending on which points you choose you get a different estimate for (say) 2100.

10 years of rapid temperature rise was followed by the latest 2 years of smaller increase. So two years ago you (or Kerry) might well have made a significantly different estimate of the likely temperature in 2100 without the data for the last two years. .

Pielke successfully predicted the shuttle disaster so his soothsaying credentials are very good. Pielke probably uses entrails or stars for his predictions so he wouldn't even notice if someone was wrong-footed by actual data.
So..

OP Wrote:Kerry’s latest views on projected global temperature change has no doubt been informed by the latest net-zero assessment of the International Energy Agency,

Really the best way to find out what the temperature will be in 2100 is to wait until 2100. Another 2 years of data might change the trend considerably - could go either way - meanwhile we have to rely on soothsayers.