Because the decade-by-decade trends identified by Chylek and his colleagues affect global weather and sea levels, it is important to accurately forecast future climate change in a smaller time frame. is essential for planning to mitigate its impacts and developing adaptation strategies. The Arctic influences the world’s climate and weather, and the melting of ice in Greenland causes sea levels to rise, threatening many coastal communities.
The amplification index in the study is the ratio of the 21-year temperature trend in the Arctic to the 21-year global temperature trend.
The study calculated an Arctic amplification index greater than 4 during the first decades of the 21st century, four times faster than the global average and significantly faster than previously published research. determined using a 30-40 year period. Previous studies have pegged the index between 2 and 3.
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From the 39 climate change models in the Paired Model Comparison Project’s widely used CMIP6 collection, the international team found four models that reasonably reproduce the first step around 1986, but no model replicates the second step in 1999. CMIP is an international collaboration of climate models using a shared set of parameters. CMIP6 was used to prepare the recent Intergovernmental Panel Climate Change Assessment Report.
“We think the first step is to increase the concentration of carbon dioxide and other pollutants in the atmosphere, because some models do,” says Chylek. second step.”
Short-term climate change is often not detected by climate models with their 30-year plus long-term period.
The study did not pinpoint exactly what caused this relatively sudden increase, but the authors speculate that a contributing cause could be a feedback of sea ice and water vapor combined with changes in the way we eat. Atmospheric and oceanic heat moves into the Arctic. The future gain in the Arctic amplification index is likely to be smaller as the temperature difference between the Arctic and the tropics decreases.
Valuable for forecasting changes in the Arctic
Chylek said the team will next study future Arctic climate projections using the four closest models to match observed warming trends, with spikes.
“Because the four models reproduce accurately at least in the first step, we think they are slightly better for predicting future climate,” says Chylek. “People often average all models and assume the set is more reliable than any single model. We show that the average doesn’t work in this case.”
The team downloaded publicly available temperature data for the Arctic from the internet and used simulation results from climate models in the CMIP6 collection.
Source: Eurekalert
