AI predicts Earth’s peak warming

Results published on December 10 Geophysical Research Lettersshowing that the hottest years ahead are likely to break existing high temperature records. The authors report that even if humanity achieves its current goal of rapidly reducing greenhouse gas emissions to net zero by the 2050s, there is a 50% chance that global warming will exceed 2 degrees Celsius.

Multiple previous studies, including the Intergovernmental Panel on Climate Change’s authoritative assessment, have concluded that decarbonization at this rate could keep global warming below 2 degrees.

“In recent years, we have seen the impact of heatwaves, heavy rainfall and other extreme weather accelerating around the world. This study shows that even in the best-case scenario, we are likely to experience more severe events than we thought. situation. Working on this issue.

This year will surpass 2023 as the hottest year on record on Earth, with average global temperatures expected to be 1.5 degrees Celsius, or nearly 2.7 degrees Fahrenheit, above pre-industrial baselines, before widespread burning of fossil fuels for electricity generation began. According to the new study, there is a nine-in-10 chance that the hottest year this century will be warmer by at least half a degree Celsius, even under rapid decarbonization.

Using artificial intelligence to improve climate predictions

In the new study, Diefenbaugh and Barnes trained an artificial intelligence system to predict how much global temperatures might rise based on the rate of decarbonization.

When training the artificial intelligence, the researchers used temperature and greenhouse gas data from a large archive of climate model simulations. However, to predict future warming, they fed the AI ​​actual historical temperatures as input, along with several widely used scenarios of future greenhouse gas emissions.

“Artificial intelligence is becoming a very powerful tool for reducing uncertainty in future predictions. It learns from many existing climate model simulations and then further refines its predictions through real-world observations,” said Barnes. . Atmospheric Science, Colorado State University.

The study adds to a growing body of research suggesting the world has almost certainly missed the chance to meet the more ambitious goals of the 2015 Paris climate agreement, in which nearly 200 countries pledged to keep long-term temperature rises “far below” Stay at 2 degrees while trying to avoid 1.5 degrees.

The second new paper published by Barnes and Diffenbaugh on December 10 Environmental Research LettersCo-author Sonia Seneviratne of ETH Zurich said that as emissions continue to rise, many regions, including parts of South Asia, the Mediterranean, central Europe and sub-Saharan Africa, will warm more than 3 degrees Celsius by 2060. earlier than expected in earlier studies.

Extremes matter

Both new studies build on research from 2023, in which Diefenbaugh and Barnes predicted how many years are left until the 1.5°C and 2°C targets are exceeded. But because these thresholds are based on average conditions over many years, they don’t tell the full story of how extreme the climate could become.

“As we look at these severe impacts year after year, we become increasingly interested in predicting the climate change even if the world fully succeeds in rapidly reducing emissions,” said Diefenbaugh, the Carla J. Foundation Professor and Kimmelman family veteran. How extreme it can get.

For a scenario in which emissions reach net zero by the 2050s – the most optimistic scenario widely used in climate models – the researchers found there was a nine-in-10 chance that the hottest year of the century would increase global temperatures by at least 1.8 degrees Celsius. Above pre-industrial baselines, there is a two-thirds chance of temperatures rising by at least 2.1 degrees Celsius.

If emissions fall too slowly to reach net zero by 2100, Diefenbaugh and Barnes found there is a nine-in-ten chance that the world’s hottest years will be 3 degrees Celsius warmer than the pre-industrial baseline. Under this scenario, temperature anomalies in many areas could be at least three times greater than in 2023.

Invest in adaptation

New forecasts underscore the importance of investing not just in decarbonization, but also in measures that make human and natural systems more resilient to intense heat, worsening droughts, heavy precipitation and other consequences of continued warming. Historically, these efforts have taken a backseat to reducing carbon emissions, with investments in decarbonization outpacing global climate finance and adaptation spending through policies such as the Inflation Reduction Act of 2022.

“Our findings show that even if all efforts and investments in decarbonization are as successful as possible, there is a real risk that without commensurate investment in adaptation, people and ecosystems will face a more extreme climate than they are accustomed to. condition.