- A handful of climate projections predict a rise in global temperatures much higher than what scientists have seen in previous models.
- Although the number raises concerns, some scientists hope the latest projections are outliers.
- A 2 degree rise in temperature could lead to rising sea levels, the death of coral reefs and dangerous water scarcity in some parts of the world. Some models are currently predicting a 5 degree rise.
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According to a report by Bloomberg.
The startling anomaly first appeared in National Center for Atmospheric Research (NCAR) models, which suggested that if Earth’s atmospheric carbon dioxide concentration doubled (as it is expected to by the end of the century), the planet could go up 5.3 degrees. hotter. This is 33% more than the group’s previous estimate.
According to Bloomberg, about a fifth of new climate model results released last year indicated similar global temperature spikes. The UK-based Met Office Hadley Center predicted a warming of 5.5 degrees, the US Department of Energy calculated a jump of 5.3 degrees, French scientists estimated a rise of 4.9 degrees and a model by Canadian scientists predicted the biggest rise: 5.6 degrees.
Scientists hope the models are an “overshoot,” Bloomberg reported. It will take scientists a long time – at least months – to figure out how to interpret the results.
Climate models estimate “climate sensitivity”, which tells scientists how much the planet will warm due to rising CO₂ concentrations. For four decades, the expected temperature rise if CO2 levels double has been around 3 degrees.
These models have a proven track record of accurately predicting climate change. A recent study from the American Geophysical Union found that climate projections over the past five decades were largely accurate – actual climate observations aligned with model predictions.
Still, climate scientists hope the new projections are outliers. About a dozen more models are yet to be released, Bloomberg reported, and they could help paint a clearer picture.
“We hope that’s not the right answer,” Klaus Wyser, senior researcher at the Swedish Meteorological and Hydrological Institute, told Bloomberg.
In the 2015 Paris climate accord – from which President Donald Trump has begun to withdraw the United States – countries pledged to cut carbon emissions to prevent global temperatures from rising by more than 2 degrees. It also set a more ambitious goal of limiting warming to 1.5 degrees, but that’s likely out of reach given that the planet has already warmed by around 1 degree.
If global temperatures rise by 2 degrees, models predict sea levels would rise by 1.6 feet, global heat waves would become much more frequent, and subtropical areas could lose a third of their freshwater supply. Almost all aquatic life in oceans around the world would be affected; 99% of coral reefs could die.
