Arctic News: guardrail

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Thursday, January 19, 2017

2016 well above 1.5°C

In December 2016, it was 6.58°C (11.84°F) warmer from latitude 83°N to the North Pole. In December 2016, the world as a whole was on average 0.82°C (1.47°F) warmer than in 1951-1980.

Temperatures are rising fast, and especially so over the Arctic Ocean. In February 2016, the world was 1.34°C (2.41°F) warmer than 1951-1980, while part of the Kara Sea was 11.3°C (20.34°F) warmer than 1951-1980, as the image on the right illustrates.

The 1951-1980 period is the default baseline used by NASA. When comparing the current temperature to years such as 1900 or 1750, the difference will be even larger, as illustrated by the image below.

In 2016, the global temperature was well above the 1.5°C (2.7°F) guardrail set by the Paris Agreement. This is illustrated by the different baselines used in image below (the use of different baselines was discussed in an earlier post), given that the Paris Agreement uses preindustrial levels as baseline.

[ click on images to enlarge ]

To some extent, the rise above 1.5°C was due to El Niño, as the trendline indicates, but the trend also indicates that temperatures will cross the 1.5°C mark in 2017 even if 2017 will be El Niño/La Niña-neutral.

Worryingly, another El Niño is actually forecast for 2017, as discussed in an earlier post.

Even more worrying is that rise of this trendline could well be too conservative.

Ocean temperatures are rising rapidly, as illustrated by the image on the right, and the rapid warming of the oceans is causing a dramatic fall in sea ice extent, as illustrated by the image below and as discussed in an earlier post.

The lack of sea ice spells trouble. Not only is snow and ice decline causing more sunlight to be absorbed (rather than getting reflected back into space as before), there are further feedbacks associated with this. As the temperature difference between the Arctic and the Equator decreases, changes are taking place to wind patterns that cause further acceleration of warming in the Arctic, as discussed in an earlier post. This in turn threatens to trigger huge amounts of methane to erupt abruptly from the seafloor.

Methane levels over the Arctic Ocean are much higher than over the rest of the world, as illustrated by the image below, showing the situation in the afternoon of January 17, 2017, with peaks reaching levels as high as 2406 ppb. Particularly worrying are the solid magenta-colored areas over the East Siberian Arctic Shelf, indicating methane levels above 1950 ppb.

When also taking into account further elements that could cause warming, a potential warming of 10°C (18°F) could eventuate by the year 2026, i.e. within about nine years from now, as discussed at the extinction page and as illustrated by the image below, from the Temperature page.