Monday, August 09, 2021

More on the Acceleration of Global Warming

Here's more on the acceleration of global warming according to the Copernicus database. Their measurements start only in 1979, but we can see that the globe has warmed about 0.8 °C in just over 40 years. And that the second-order fit (=> acceleration) is better than the linear fit). But their dataset doesn't give us the total warming since the pre-industrial era.

However, if we project these trendlines out, we see that, relative to 1979, we're on a path to have about 1.2°C of warming by 2030 and 2.0°C of warming by 2050. Not good at all.

The only way to get decent figures on this crappy blogging system is if you click on them.


Layzej said...

"we're on a path to have about 1.2°C of warming by 2030"

Not counting the warming prior to 1979. It seems like we had already warmed about 0.4C prior to 1980. That would put us at 1.6°C by 2030.

Curiously, the IPCC AR6 suggests we may not reach 1.5C by 2040 under all scenarios (See Table SPM.1). Seems a bit optimistic to me.

David Appell said...

Thanks for that comment.

RealClimate has a post along these lines today:

JoeT said...

I think Carbon Brief has a clearer explanation when 1.5 C will be exceeded.

Recently I did my own estimate based on cumulative emissions. I used the Berkeley Earth data set, adjusted the baseline to 1850 - 1900, did a loess smooth and concluded that we are presently at 1.3 C above the baseline. The confusing thing about the IPCC and the media reports is that they list the global mean temperature increase at 1.1 C. But the IPCC is doing an average over 2011 - 2020.

If one looks at the 2020 World Energy Outlook by the IEA, they forecast roughly flat CO2 emissions out to 2070 as their benchmark scenario.

If I take constant 2019 emissions from here on out, I get that 1.5 C would be reached in 2028. The IEA scenario is probably closest to SSP2-4.5 for the IPCC. Carbon Brief has the 1.5C exceedance year for that scenario as 2030.

David Appell said...

So Joe, it seems you would say 1.5 C is essentially unavoidable at this point, for all practical purposes.

Layzej said...

IPCC v6 shows an eventual return below 1.5 for lowest emission scenarios.

JoeT said...

David, I'm not the only one who thinks 1.5C is pretty much unavoidable. But the world should still try to shoot for 1.5C and hope we don't exceed it by much.

On the positive side, CO2 emissions have fallen from 3% growth per year to 1% growth over the last 10 years or so. Emissions are finally looking like they are rolling over (and I didn't count 2020 which was an anomaly).

The other bit of good news I think is there is about an even chance that the Clean Energy Payment Program might make it through the Senate reconciliation process. That would be huge.

Phil Clarke said...

A sense of déjà vu hung in the air as Washington and Oregon faced scorching temperatures in the midst of the region’s second major heatwave this summer.

Temperatures in Portland reached 102 F (39 C) by late afternoon on Thursday and Seattle reached highs in the 90s, with more heat expected on Friday.

Although the temperatures were not expected to be as severe as during the heatwave in late June, when some areas exceeded 115F (46C), several cities had put in excessive heat warnings.

People sleep at a cooling shelter set up during an unprecedented heatwave in Portland, Oregon, 27 June.

In Seattle, the temperature was set to reach 96F (36C) on Friday, while the record for that day is only 92F (33C), according to Eric Schoening, a National Weather Service meteorologist. Yakima, in southern Washington, could hit 104F (40C) Friday.

In Beaverton, Oregon, where temperatures could reach 102F (39C) again on Friday, the community center was offering overnight air-conditioned shelter for those in need.

Come on Cliff. Come on Heartland Fellow Anthony. Come On Willis. Surely this cannot be more evidence of the 'unequivocal' AGW. Get scribbling!

Balázs said...

"Come on Cliff. Come on Heartland Fellow Anthony. Come On Willis. Surely this cannot be more evidence of the 'unequivocal' AGW. Get scribbling!"
At the moment they pretend nothing has happened. I think they are waiting for Cliff to come up with yet another explanation why this is just "variability".