The torrential rains that hit Sydney in October—eight inches in one day—are but a precursor of what’s to come, according to a study by US climate scientists published this week in the journal Nature Climate Change.
Warmer air holds more water. As global temperatures rise due to increases in atmospheric carbon, parts of North America can expect fourfold increases in the frequency of extreme rainfall events by the end of this century, coupled with a 70 percent increase in the severity of those events, the study predicts.
A map published by the US National Center for Atmospheric Research, which carried out the research, indicates that Eastern Nova Scotia, Cape Breton, and PEI will be among the areas hardest hit by torrential downpours.
The scientists used an extensive storm dataset and a year of supercomputer time to model the rainfall predictions. The models assumed on a five degree Celsius increase in temperature, the increase expected by 2100 if carbon emissions continue unabated.
“These are huge increases,” NCAR scientist Andreas Prein, lead author of the study, said in a news release. “Imagine the most intense thunderstorm you typically experience in a single season. Our study finds that, in the future, parts of the U.S. could expect to experience five of those storms in a season, each with an intensity as strong or stronger than current storms.”
October’s storm completely overwhelmed Sydney’s infrastructure for handling surface water drainage. Anjuli Bamzai, program director in the US National Science Foundation’s Directorate for Geosciences, which funded the research, noted that, “Extreme precipitation events affect our infrastructure through flooding, landslides and debris flows.”
From the release:
Prein cautioned that this approach is a simplified way of comparing present and future climate. It doesn’t reflect possible changes to storm tracks or weather systems associated with climate change. The advantage, however, is that scientists can more easily isolate the impact of additional heat and associated moisture on future storm formation.
“The ability to simulate realistic downpours is a quantum leap in climate modeling. This enables us to investigate changes in hourly rainfall extremes that are related to flash flooding for the very first time,” Prein said. “To do this took a tremendous amount of computational resources.”
Yet more evidence why industrialists, who insist we forge ahead with new fossil fuel developments, and environmentalists who obsess over trifling objections to necessary green energy developments, need to focus on the impending global calamity posed by climate change.