Rising sea levels, melting glaciers, and ocean heatwaves dominated 2023’s climate news, with global temperatures soaring to almost 1.5 degrees Celsius above pre-industrial levels. Scientists are trying to determine the cause of this sudden surge in warming.
They considered factors like greenhouse gases, volcanic eruptions, and El Niño events, but found an unexplained gap of 0.2 degrees Celsius. A research team from the Alfred Wegener Institute proposes that changes in Earth’s cloud cover may be the explanation.
Studies analyzed satellite data from NASA, combining it with weather models and observational data. The results showed a worrying trend: 2023 recorded the lowest planetary albedo since at least 1940. This refers to how much sunlight a planet reflects back into space.
Earth’s balance of reflected and absorbed sunlight plays a crucial role in shaping its climate and energy budget. Changes in albedo can accelerate warming, as seen in the melting of ice caps exposing darker surfaces that absorb more sunlight.
The decline in low-altitude clouds is believed to be the cause of this drop in albedo. This trend was most pronounced over the Atlantic, which coincidentally saw unusual heat records in 2023. With fewer low clouds, Earth’s cooling effect diminishes, contributing to warmer temperatures.
Climate scientists point to a feedback loop between warming and cloud loss as a possible explanation for the sudden surge in global warming. If this is indeed happening, it could lead to intense warming, potentially crossing the critical 1.5-degree threshold sooner than expected.
Source: https://www.earth.com/news/rapid-surge-in-global-warming-may-have-an-unexpected-source