Wednesday, 18 December 2019

Sam Carana asks: extinction in 2020?



Extinction in 2020?

Arctic News,
17 December, 2019


Above image depicts how humans could go extinct as early as 2020. The image was created with NASA LOTI 1880-Nov.2019 data, 0.78°C adjusted to reflect ocean air temperatures (as opposed to sea surface temperatures), to reflect higher polar temperature anomalies (as opposed to leaving out 'missing' data) and to reflect a 1750 baseline (as opposed to a 1951-1980 baseline), with two trends added. Blue: a long-term trend based on Jan.1880-Nov.2019 data. Red: a short-term trend, based on Jan.2009-Nov.2019 data, to illustrate El Niño/La Niña variability and how El Niño could be the catalyst to trigger huge methane releases from the Arctic Ocean.

How was above image created? Let's first look at the baseline. The NASA defauls baseline is 1951-1980. The added trend in the image below shows early 1900s data to be well below this 1951-1980 baseline. In this analysis, a 0.28°C adjustment was therefore used to reflect this, and to reflect a 1750 baseline, a further 0.3°C was used, adding up to a 0.58°C baseline adjustment.





Furthermore, the NASA Land+Ocean temperature index (LOTI) uses sea surface temperatures, but ocean air temperatures seem more appropriate, which adds a further 0.1°C adjustment. Also, when comparing current temperatures with preindustrial ones, it's hard to find data for the polar areas. Treating these data as 'missing' would leave important heating out of the picture. After all, the polar areas are heating up much faster than the rest of the world, and especially so in the Arctic region. Therefore, a further 0.1°C adjustment was used to reflect higher polar temperature anomalies, resulting in the above-mentioned 0.78°C adjustment.

Finally, the red trend illustrates El Niño/La Niña variability. As discussed in a recent post, an El Niño is forecast for 2020 and this could be the catalyst to trigger huge methane releases from the Arctic Ocean.

The image below shows El Niño/La Niña variability going back to 1950, added to the NOAA monthly temperature anomaly.





As said, the Arctic region is heating up much faster than the rest of the world. There are several reasons why this is the case. Decline of the sea ice makes that less sunlight gets reflected back into space and that more sunlight is reaching the Arctic Ocean. This also causes more water vapor and clouds to appear over the Arctic Ocean. Furthermore, Arctic sea ice has lost most of the thicker multi-year ice that used to extend meters below the surface, consuming huge amounts of ocean heat entering the Arctic Ocean along ocean currents from the North Atlantic and the North Pacific oceans.

[ created with NOAA Arctic Report Card 2019 image ]


The above-mentioned feedbacks (albedo changes and more water vapor and clouds) contribute to higher temperatures in the Arctic. As the temperature difference between the North Pole and the Equator narrows, the jet streams change, which can lead to further Arctic heating, i.e. higher temperatures of the atmosphere, higher temperatures of the water flowing into the Arctic Ocean from rivers and higher temperatures of the inflow of water from the Atlantic Ocean and the Pacific Ocean.



As above image shows, the temperature rise of the oceans on the Northern Hemisphere is accelerating. This constitutes a critical tipping point, i.e. there are indications that a rise of 1°C will result in most of the sea ice underneath the surface to disappear. This sea ice used to consume the inflow of warm, salty water from the Atlantic Ocean and the Pacific Ocean. So, while there may still be sea ice left at the surface, since low air temperatures will cause freezing of surface water, the latent heat buffer has gone.




As long as there is sea ice, this will keep absorbing heat as it melts, so the temperature will not rise at the sea surface. The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.

The danger is that, as Arctic Ocean heating accelerates further, hot water will reach sediments at the Arctic Ocean seafloor and trigger massive methane eruptions, resulting in a huge abrupt global temperature rise. As discussed in an earlier post, a 3°C will likely suffice to cause extinction of humans.



The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• NASA - GISS Surface Temperature Analysis (GISTEMP v4)
https://data.giss.nasa.gov/gistemp/maps/index_v4.html

• NOAA Northern Hemisphere ocean temperature anomalies through November 2019
https://www.ncdc.noaa.gov/cag/global/time-series/nhem/ocean/1/11/1880-2019

• NOAA - Monthly temperature anomalies versus El Niño
https://www.ncdc.noaa.gov/sotc/global/201911/supplemental/page-3

• 2020 El Nino could start 18°C temperature rise
https://arctic-news.blogspot.com/2019/11/2020-el-nino-could-start-18-degree-temperature-rise.html

• NOAA Arctic Report Card 2019
https://www.arctic.noaa.gov/Report-Card/Report-Card-2019

• Critical Tipping Point Crossed In July 2019
https://arctic-news.blogspot.com/2019/09/critical-tipping-point-crossed-in-july-2019.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

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