How hot will it get?

5 months ago 43

Currently, the temperature in the Northern Hemisphere is higher than it was last year at this time of year, as illustrated by the image below, created with University of Maine content. The image shows that a temperature of 21.1°C was reached in the Northern Hemisphere on June 17, 2024. The question is: Will temperatures over the next few months exceed the high temperatures reached last year?

El Niño is no longer prevalent and La Niña conditions are expected to be dominant soon, as illustrated by the NOAA ENSO update on the right, from an earlier post.

Nonetheless, there are fears that temperatures will remain high and continue to rise, as self-amplifying feedbacks have taken over as the dominant drivers of the temperature rise. This was discussed earlier, in recent posts such as this one and this one.

There are numerous feedbacks that can further accelerate the temperature rise. Higher temperatures come with more water vapor in the atmosphere, an important feedback since water vapor is also a potent greenhouse gas.

Surface precipitable water reached a record high of 27.139 kg/m² in July 2023, as illustrated by the image below, adapted from NOAA, from an earlier post. Worryingly, a value of 26.138 kg/m² was reached in May 2024, much higher than the 25.378 kg/m² in May 2023, which raises fears that surface precipitable water will reach an even higher peak in 2024 than was reached in 2023.

Rising temperatures are also behind the decline of sea ice and permafrost, which can in turn result in huge emissions of carbon dioxide, methane and nitrous oxide.

Deformation of the Jet Stream is another feedback. This occurs strongly in the Northern Hemisphere as the Arctic heats up more rapidly than the rest of the world, narrowing the temperature difference between the Tropics and the Arctic.

Deformation of the Jet Stream can amplify extreme weather events such as storms that cause flooding and heatwaves that cause forest fires.

[ click on images to enlarge ]

Deformation of the Jet Stream also enables strong winds to develop over the North Atlantic, which can at times strongly accelerate the speed at which hot water is flowing toward the Arctic Ocean along path of the Gulf Stream.

A deformed Jet Stream can temporarily speed up this flow, causing huge amounts of Ocean heat to get abruptly pushed into the Arctic Ocean in the path of the Gulf Stream.

The image on the right shows hot water getting pushed along the path of the Gulf Stream from the Gulf of Mexico toward the Arctic Ocean. The image shows sea surface temperatures as high as 32.3°C on June 22, 2024.

Two tipping points threaten to get crossed as temperatures rise and Arctic sea ice disappears, i.e. the latent heat tipping point and the seafloor methane tipping point, as discussed in an earlier post.

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.