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Author Topic: Global Surface Air Temperatures  (Read 573864 times)

wolfpack513

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Re: Global Surface Air Temperatures
« Reply #2200 on: May 20, 2020, 09:09:18 PM »
Berkeley Earth global mean through April 2020.  The 1860-1910 mean is -0.36°C. The end point of the 20-year trend in 2020 is 0.90°C.  That’s a total of 1.26°C warming(of course a little more with some AGW prior to 1860). 

Current trend is 0.21°C per decade.  That conservatively puts us at +1.5°C in less than 12 years.  IPCC and supporting impacts use 20 year means.  So single years or months is incorrect to say “we’ve already past 1.5°C.”

Hefaistos

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Re: Global Surface Air Temperatures
« Reply #2201 on: May 21, 2020, 12:53:33 AM »
OTOH the more sensitive satellite only temp. data, i.e. RSS and UAH, show strong declines in the last couple of (Covid) months.

https://www.woodfortrees.org/graph/gistemp/last:12/offset:-0.43/plot/hadcrut4gl/last:12/offset:-0.29/plot/rss/last:12/offset:-0.13/plot/uah/last:12

wolfpack513

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Re: Global Surface Air Temperatures
« Reply #2202 on: May 21, 2020, 01:55:20 AM »
OTOH the more sensitive satellite only temp. data, i.e. RSS and UAH, show strong declines in the last couple of (Covid) months.

https://www.woodfortrees.org/graph/gistemp/last:12/offset:-0.43/plot/hadcrut4gl/last:12/offset:-0.29/plot/rss/last:12/offset:-0.13/plot/uah/last:12

As stated a couple months ago, the Australian wildfires influenced L-T satellite readings.  Your trend is just the residence time of aerosols precipitating out.
« Last Edit: May 21, 2020, 02:06:19 AM by wolfpack513 »

Hefaistos

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Re: Global Surface Air Temperatures
« Reply #2203 on: May 21, 2020, 06:31:28 AM »

As stated a couple months ago, the Australian wildfires influenced L-T satellite readings.  Your trend is just the residence time of aerosols precipitating out.

That's a claim.
What's the evidence?

Australian wildfires apparently were in the southern hemisphere only, as well as the haze/smoke. Thus, we would expect to see the signal of a (relative) temperature decrease in the SH only.
But data don't support that claim. The chart is with Hadcrut data for NH and SH, up to feb. 2020. The major fires peaked during December–January. The wildfires finished at the end of February, beginning of March. Thus, the temperature signal due to aerosols should be at its strongest from December 2019 to February 2020.

https://www.woodfortrees.org/plot/hadcrut4nh/from:2015/plot/hadcrut4sh/from:2015

https://en.wikipedia.org/wiki/2019%E2%80%9320_Australian_bushfire_season

For some comparison of the wildfires over time:
https://www.theguardian.com/australia-news/2019/nov/22/australia-bushfires-factcheck-are-this-years-fires-unprecedented
« Last Edit: May 21, 2020, 06:56:28 AM by Hefaistos »