Climate Change Affecting Southeast Summer Rainfall

Get ready to get more use out of your galoshes and sun shades if you live in the Southeastern US. Current research from Duke University shows that the abnormally wet or abnormally dry summers over the past few decades are due in part to climate change. More importantly, they're likely to increase in the future. Why? Because of an interesting interaction between human induced-warming and natural atmospheric phenomena.

You may have heard of El Niño or La Niña and their effects on seasonal climate. In the Southeast, for example, La Niña generally leads to dryer conditions. Less known outside the realm of meteorology is the North Atlantic Subtropical High (NASH) or Azores High. It forms as a high pressure system just off Bermuda. Fluctuations in the NASH to the north or south can affect rainfall patterns in the Southeast.

Researchers have found that in the past six decades, the NASH is shifting in two ways. First, its western front is extending closer to the United States. Second, it has been growing more intense. Both factors likely translate into more extreme rainfall or drought in the Southeast in a given summer.

So what’s causing these shifts? According to Wenhong Li, the lead author,

“Our analysis strongly suggests that the changes in the NASH are mainly due to anthropogenic warming.”

What’s even more worrisome is that our role in altering the NASH will continue as long as carbon dioxide emissions continue to increase.

So what does this mean for residents and business in the Southeast? It means the concept of a 100-year flood is out the door and with it current insurances rates and estimates. It means ecosystems, including fragile areas like the Everglades, are likely to undergo serious changes. It means more property damage and loss of life if adaptation measures aren’t taken soon. It means mitigation actions should be taken sooner or conditions are likely to worsen.

Surely this should spur political action. Yet in the Southeast, Republican candidates for governor in Alabama and Florida both deny climate change (as well as, sadly, the Democrat in Alabama). In general, 27 out of 37 Republican gubernatorial hopefuls do not accept the evidence of climate change according to an analysis by Wonk Room.

Yet big Republican gains in Congress and governorships likely means nothing will be done. For states in the Southeast, that means there’s less likely to be money put proactively towards adaptation strategies. For states across the country, that means less efforts will be made to mitigate greenhouse gases, which means still more woes for the Southeast.

With evidence like this showing the effects of climate change clear and present, it’s amazing that the US is home to the only major political party in the world that questions the science. Yet as the National Review notes, on climate change "the GOP is stampeding toward an absolutist rejection of climate science that appears unmatched among major political parties around the globe, even conservative ones.”

Maybe Republican fundraisers have large investments in the galoshes and sun shades industries we’re unaware of.

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