Experts: Climate a big factor to Ida’s severity
As Connecticut recovers from historic flooding caused by the remnants of tropical depression Ida, climate scientists warn that severe weather patterns may become a more common occurrence in the future.
Climate change has in part prompted a “feast or famine” of water, said Michael Dietz, director of the Connecticut Institute of Water Resources at the University of Connecticut. The region will begin to experience periods of drought followed by surging rainstorms over a much shorter time frame. And when the ground becomes over-saturated with water, flooding becomes more frequent.
“The frequency of these things changing, that’s definitely on my mind — our precipitation regime has already changed due to climate change,” Dietz said. “Looking backwards on data, we’ve seen a real shift and we’re getting these bigger rain events more often.”
Already, the state has experienced four major tropical storms in the span of two months — a “tremendously abnormal” occurrence, said Gary Lessor, a meteorologist at Western Connecticut State University.
Stamford, for example, experienced in a span of 16 to 20 hours the rainfall levels of nearly two months of precipitation in a normal year, Lessor said. Along the shoreline, rainfall was about six inches above normal levels.
“We’ve definitely seen worse, but there was still a lot of impact from this one,” Lessor said. “The weather patterns are properly aligned for everything to come up here.”
Peter Raymond, an environmental studies professor at Yale, said flooding reports across the region are concerning to scientists because they are directly linked to climate change. Climate science shows that as the atmosphere warms up, it can hold more water, which causes storms to have higher and more destructive amounts of rainfall, Raymond said.
Ida gained strength rapidly right before landfall as it moved over the Gulf of Mexico earlier this week, with water temperature a few degrees warmer than average, according to the National Oceanic and Atmospheric Administration. It caused significant damage in Louisiana before being downgraded into a tropical depression and moving northeast.
Ida caused destruction in New York and New Jersey before moving to Connecticut, bringing widespread flooding.
In addition to the flooding, there are other public safety concerns, Dietz said. He advises people to look out for notifications of contaminated water in the coming days as raw sewage discharges into waterways.
“Stormwater goes into the same system as sewage, and when there’s too much water,
the treatment plants can’t handle it,” Dietz said. “You’re going to see notifications about beaches being closed now, because of high bacteria, and that’s exactly where it’s from.”
Raymond said the problem
is more systematic than municipalities lacking adequate emergency preparation.
To see any change in extreme weather patterns, “it all goes back to decreased fossil fuel emissions
to the atmosphere,” Raymond said. “There’s also flood control and mitigation you can do, but with respect to the root of the problem — it is policies for decreasing fossil fuels and people changing their behavior.”