For the January–August period, 2015 is well ahead of any previous year on record for global average temperature and a full 0.1ºC ahead of second place 2010.
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| Source: NCEI |
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| Source: NCEI |
Monday, September 21, 2015
2015 Easily on Pace for Warmest on Record
Last week, the August climate numbers were released by the National Centers for Environmental Information (NCEI) and not surprisingly 2015 continues to be a hot one.
For the January–August period, 2015 is well ahead of any previous year on record for global average temperature and a full 0.1ºC ahead of second place 2010.
The numbers for August the past two years are really out there. August 2014 was 0.09ºC warmer than second place August 2009, and then August 2015 doubled down and added another 0.09ºC.
These big numbers reflect the long-term global warming combined with the strong El Nino that has developed in recent months. Similarly, 1998 was a remarkably strong El Nino and it was a real outlier in terms of temperature (see the top bar chart). Those wishing to argue that global warming "stopped" have frequently used 1998 as the start point of their time series as it results in a relatively flat trend over the last several years. As we have discussed (see Global Warming Hasn't Stopped), global warming never stopped, even if the short-term trend in global atmospheric temperatures was small, and it was only a matter of time until the shorter-term trend produced by climate variability (such as associated with the development of a strong El Nino) phased with the long-term trend in a way to give us a big warm up. That time is now.
For the January–August period, 2015 is well ahead of any previous year on record for global average temperature and a full 0.1ºC ahead of second place 2010.
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Any idea as to what may have caused the reversal in temps around 1945?
ReplyDeleteAtomic bombs tested in New Mexico and used twice against Japan
ReplyDeleteOK, Atmospheric testing of Atomic Bombs ran from 1945-1980. There appears to be a pretty good correlation during that time with a reversal of warming which began around 1910. Perhaps we should begin dropping more bombs.
ReplyDeleteSorry...nothing to do with atomic bombs. The leading mechanisms for the slowdown are cooling associated with the increase in pollution/aerosols during the post WWII industrial boom and/or oceanic conditions. Note that the warming from about 1910 to 1945 appears to be due primarily to an increase in solar output.
ReplyDeleteHi Jim, "those wishing to argue that global warming stopped" are the authors of the last IPCC report, where the global warming hiatus was amply discussed, and all the authors of 50+ papers published lately in the literature discussing different possible explanations for the hiatus.
ReplyDeleteWhile the NOAA and GISTEMP records are observational data and they clearly show very warm temperatures in the last few years, including this one, the NASA MSU satellite records are also empirical data and neither UAH or RSS have detected this latest warmth. Both agree that the hiatus lasts for about 18 years now. Given the fact that models show more warming aloft, I think that this discrepancy should be addressed by scientists, rather than ignored with a constant focus on the more alarmist surface records.
Leaving that aside, my warmest thanks for your weather/nature related posts. Last Saturday I was hiking in the peaks of the Albion Basion and I could hardly believe the beauty that the sudden arrival of autumn has brought to the Wasatch.
Best regards, Mikel
A hiatus in global surface temperature warming is not the same thing as global warming stopping. It is well documented that the climate system has continued to warm, being dominated by warming oceans over the last couple decades. Scientists were and are still trying to figure out why the atmosphere has not kept pace. There are a lot of theories for this in the literature and it is important to understand, but statisticians have shown that this pause in rising surface air temperatures is statistically insignificant in terms of the long-term warming trend. In a recent blind test of economists, they agreed: http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/sep/18/in-a-blind-test-economists-reject-the-notion-of-a-global-warming-pause.
DeleteHi Jim, if you are acquainted w the satellite data I'd like to see what you have to say on the discrepancy. This has come up in my global warming reading a decade or so ago and there was an explanation which I forgot. Meantime, a few weeks back, maybe it was that cold spell, I got a wild hair and downloaded the NOAA climate data for Alta. January overnight low for the period 1945-2015 averaged 13 degrees F, w a low of 3 in 1949 and high of 22, you may be surprised, in 1986, Second was 21 in 2015. Trend increase for the period is 1 degree every 18 years. 10 year average was 11.8 for 1945-1954, and 13.8 for 2006-2015; minimum in the last 10 years was 6 in 2008. January daytime high at Alta averaged 30 w a trend increase of 1 degree every 44 years. Five of the last ten years the January daytime high has exceeded the essential 32. In terms of us Weenies, its Alta surface that matters. Lower locations are almost as important, but I've more or less resigned myself to Neff's starts being a special treat as I become old. If I get a double wild hair, I'll e-mail you the file and pester you about its meaning. For now, we must pray for more snow, less wind, and Arctic air
ReplyDeleteBoth the surface and satellite datasets have their warts and measure different things. The surface temperature record isn't perfect, but there seems to be pretty solid consensus now concerning the warming in the instrumented record. Plus, this is where the people, plants, and animals live, so to speak. The satellite record ain't a panacea. There are adjustments that need to be made to the data and, while there is agreement that there's been warming, there's a wider range of results out there in the literature.
Deleteisn't the USCRN supposed to be the most accurate data available?
ReplyDeleteand the only non adjusted data?
no warming since the data started 10 yrs ago.
http://www.ncdc.noaa.gov/temp-and-precip/national-temperature-index/time-series?datasets[]=uscrn¶meter=anom-tavg&time_scale=p12&begyear=2004&endyear=2015&month=12
Brief description of the USCRN here: https://www.ncdc.noaa.gov/crn/overview.html
DeleteThe graph you note is for the contiguous US, so trends will be influenced by regional climate variability, especially during such a short-term period (~10 years).