Arctic News: SMOC

Showing posts with label SMOC. Show all posts

Saturday, July 12, 2025

Will humans go extinct soon?

The image below shows the June 2025 temperature anomaly versus 1951-1980, using ERA5 data.

[ June 2025 temperature anomaly, click on images to enlarge ]

[ from earlier post, click to enlarge ]

The above image shows relatively low anomalies over the Arctic Ocean, with a relatively cool area persisting in the North Atlantic, south of Greenland. This appears to reflect heavy melting, slowing down of the Atlantic Meridional Overturning Circulation (AMOC) and strong evaporation followed by more rainfall further down the track of the Gulf Stream, as illustrated by the image on the right.

The above image also shows very high anomalies over Antarctica and over the Antarctic sea ice. This appears to reflect a reversal of the Southern Meridional Overturning Circulation (SMOC).

Covering more than 70% of Earth’s surface, our global ocean has absorbed 90% of the warming that has occurred in recent decades due to increasing greenhouse gases, and the top few meters of the ocean store as much heat as Earth's entire atmosphere, as described by a NASA post. A small change in this ratio could result in a huge rise in the global air temperature, and studies warn about changes that are occurring in the AMOC and SMOC, as discussed in earlier posts such as this one.

A 2024 study led by Judd finds that climate sensitivity has historically been about 8°C. According to James Hansen, equilibrium global warming for today’s amount of greenhouse gases is 10°C, which includes a 2°C rise that would eventuate by the falling away of the aerosols that currently mask the temperature rise.

[ NOAA ENSO outlook ]

Meanwhile, the IPCC keeps down-playing the potential impact of feedbacks such as changes to ocean currents, wind patterns, clouds, water vapor, sea ice and permafrost, and the temperature is likely to increase strongly with a new El Niño. For now, temperatures remain suppressed due to borderline La Niña conditions (image right).

The image below shows monthly temperature anomalies through June 2025, based on ERA5 anomalies vs 1951-1980 from Jan 2014-June 2025 (red circles).

In the above image, data are adjusted by 1°C to reflect a pre-industrial base (black circles). Cubic trends are added to show that 3°C could be crossed late 2028 (red) or early 2027 (black).

A 3°C rise constitutes an important threshold, since humans will likely go extinct with such a rise. As illustrated by the image below, we may already be more than 2°C above pre-industrial and face a potentially huge temperature rise over the next few years.

[ from the post When will humans go extinct? ]

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.