Links tagged “pause”

Hulme: "January  12021, a new World Meteorological Organisation (WMO) climatological standard normal came into effect. The ‘present-day’ climate will now formally be
represented by the meteorological statistics of the period 1991-2020, replacing those from 1961-1990. National Meteorological Agencies in member states are instructed to issue new standard normals for observing stations and for associated climatological products. Climate will ‘change’, one might say, in an instant; today, the world’s climate has ‘suddenly’ become nearly 0.5°C warmer. It is somewhat equivalent to re-setting Universal Time or adjusting the exact definition of a metre." ...

"So, what is the significance of the move to a new 1991-2020 WMO normal in January 2021? On the one hand, it is a pragmatic move to redefine ‘present-day’ climate for operational applications to that of the most recent 30-year period. On the other hand, it puts into play a third climatic baseline. Already existing is the ‘pre-industrial’ climate of the late nineteenth century and the ‘historic’ climate’ of 1961-1990, the latter about 0.3°C warmer than the former. And now there is the new ‘present-day’ climate of 1991-2020, in turn about 0.5°C warmer than the ‘historic climate’ of 1961-1990." ...

"Combining a climatic tolerance of 2°C—or indeed 1.5°C—with a pre-industrial baseline yields a very different climate target than, say, using a 1986-2005 baseline, the period widely adopted by IPCC AR5 Working Group I as their analytical baseline. The choices of both baseline and tolerance are politically charged. They carry significant implications for historic liability for emissions (La Rovere et al., 2002), for policy design (Millar et al., 2017) and for possible reparations (Roberts & Huq, 2015)."

AP: 'Hottest year on record': 2020 sets yet another global temperature record

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Rebuttal: David Whitehouse of The Global Warming Policy Forum: "A temperature anomaly for 2020 of 0.98 +/- 0.15 °C compared to 1.00 +/- 0.15 °C for 2016 (which was the year with the strongest recorded El Nino). The difference is trivial, especially since the precision of the mean is reported to thousandths of a degree. Looking at NOAA’s data for previous years you can see that every year since 2015 falls within one standard deviation of the mean. Such a simple and unbiased view of the data leads to a much more justifiable headline for the data: There has been no significant warming trend for 5 years, as NOAA has confirmed." ... 

"A number of months in early 2020 were affected by El Niño conditions, very different from what the WMO Secretary-General has claimed. It is true that 2016 would have been cooler but for the El Nino and 2020 warmer but for the La Nina. However, as I pointed out in my previous post, the El Nino effect can be seen over several years making estimates for greenhouse gas forcing problematic." ... 

"The increase in atmospheric CO2 between 2015-2019 made no difference to global temperatures and neither has the 7% fall in global CO2 emissions observed in 2020."

Also see: Here we go again: 2020 claimed to be ‘tied with 2016’ for ‘Hottest year’ declaration

Christopher Monckton: "At long last, following the warming effect of the El Niño of 2016, there are signs of a reasonably significant La Niña, which may well usher in another Pause in global temperature, which may even prove similar to the Great Pause that endured for 224 months from January 1997 to August 2015, during which a third of our entire industrial-era influence on global temperature drove a zero trend in global warming. ... As we come close to entering the la Niña, the trend in global mean surface temperature has already been zero for 5 years 4 months. 

However, the new Pause is at a surface-temperature plateau 0.3 C° above the old Pause."