Wednesday, November 27, 2024

Coral bleaching tipping points and the death of Arctic ice


Sea Surface Temperature anomalies range from 1°C (yellow), 3°C (red), and > 5°C (black). 
Purple anomalies are <1°C

A two-year experiment found that coral reefs could survive in heated water better than expected.

BUT, the experiment only tested temperature increases of 2°C.

The target negotiated in Paris in 2015 was to keep average global temperatures this century to “well below” 2°C above pre-industrial levels. Currently, the world is on track for an increase of 2.6-3.1°C. Earth passed over the coral bleaching tipping point in the 1980s.

It takes a 1°C (yellow) anomaly for a month to cause coral reef bleaching, but black areas in the map above mark Arctic Ocean anomalies more than 5°C above the average historical temperature in the warmest month! These extreme marine heat waves herald imminent loss of summer Arctic Ice and even more rapidly rising global temperatures in the near future. As white Polar ice melts and is replaced by dark blue water, the albedo effect will accelerate runaway global warming: loss of Arctic summer ice will increase sunlight absorbed at the surface from 40% to 90%.

There is little time left for either coral reefs or Arctic ice if we don’t reverse CO2 increase immediately!