Arctic News: Temperature rise threatens to accelerate even more

Monday, July 8, 2024

Temperature rise threatens to accelerate even more

Global temperature

[ from earlier post ]

The above image, from an earlier post, shows that the February 2024 temperature was 1.76°C above 1885-1915, potentially 2.75°C above pre-industrial (bright yellow inset right). The image was created by Sam Carana for Arctic-news.blogspot.com with an April 2024 data.giss.nasa.gov screenshot. The red line (6 months Lowess smoothing) highlights the steep rise that had already taken place in early 2023.

The image below, created with Climate Reanalyzer content, shows that June 2024 was substantially hotter than June 2023, which is significant since we're not in an El Niño anymore. Moreover, monthly temperatures are also rising.

According to Copernicus, the global-average temperature for the past 12 months (July 2023 – June 2024) has been more than 1.5°C above the 1850-1900 average. Carlo Buontempo, Director of the Copernicus Climate Change Service (C3S), adds: "June marks the 13th consecutive month of record-breaking global temperatures, and the 12th in a row above 1.5°C with respect to pre-industrial. This is more than a statistical oddity and it highlights a large and continuing shift in our climate." Note that anomalies from a genuinely pre-industrial base could be much higher, as the image at the top discusses.

Carbon dioxide growth

CO₂ at Mauna Loa was 426.91 ppm in June 2024, 3.23 ppm above June 2023, close to the 3.36 ppm growth in 2023, which is the highest annual growth on record up to now, as illustrated by the compilation image below, created with NOAA content.

Furthermore, CO₂ in June is typically lower than it is in May, but it was (slightly) higher in June 2024 than it was in May 2024.

Sea surface temperatures

On July 9, 2024, sea surface temperatures were back at about 21°C again. For more than a year, sea surface temperatures have been at around 21°C, much higher than in previous years, as illustrated by the image below.

Feedbacks and further developments

Higher temperatures come with feedbacks, as illustrated by the image below, from an earlier post.

[ from earlier post ]

Deformation of the Jet Stream 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 combined with high sea surface temperatures can temporarily speed up this flow, by strengthening storms and hurricanes along the path of the Gulf Stream, resulting in huge amounts of ocean heat to get abruptly pushed into the Arctic Ocean.

The image below shows sea surface temperatures as high as 32.5°C on July 11, 2024, with hot water getting pushed along the path of the Gulf Stream from the Gulf of Mexico toward the Arctic Ocean.

The danger is that such feedbacks and further developments will accelerate the temperature rise even more. Critical in this respect is the condition of Arctic sea ice.

Arctic sea ice decline

The image below, adapted from the Danish Metereological Institute, indicates that Arctic sea ice volume is at a record low for the time of year, as it has been for most of the year. At the same time, sea ice extent is still relatively large; Arctic sea ice extent was 3% below average in June 2024, close to the values observed most years since 2010, according to Copernicus. The implication is that sea ice must be very thin.

The combination image below, from an earlier post and adapted from the University of Bremen, indicates that most of the thicker sea ice has melted in the course of June 2024, and that the latent heat buffer may be gone soon.

Latent heat buffer

Sea ice constitutes a buffer that consumes ocean heat; the temperature of the water will not rise as long as there is ice, but once all ice has melted, further heat will raise the temperature of the water.

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 Buffer has gone, feedback #14 on the Feedbacks page ]

Loss of the latent heat buffer threatens to strongly heat up the Arctic Ocean, and this increases the danger that further heat will reach methane hydrates at the seafloor of the Arctic Ocean, causing them to get destabilized resulting in eruption of methane from these hydrates and from free gas underneath that was previously sealed by the hydrates.

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.