Dual disasters: How is climate change worsening wildfires and hurricanes?

We’re barely over halfway through the nation’s hurricane and wildfire seasons, and both have already been devastating and record-breaking.

This extraordinarily busy Atlantic hurricane season – like the catastrophic wildfire season on the West Coast – has focused attention on the role of climate change.

Yet a question arises: How could climate change worsen both the wildfire and hurricane seasons? Aren’t they “opposite” weather phenomena?

No, said J. Marshall Shepherd, an atmospheric scientist at the University of Georgia.

“We’ve always known that climate change would make extremes more extreme on all sides of the ledger. It’s counterintuitive to some people that global warming can amplify drought and heavy rain, but it’s simply physics,” he said.

Penn State University meteorologist Michael Mann, speaking about whether wildfires and hurricanes are opposites, said “actually, in a sense, they’re not.

Mann said that as we continue to warm the planet – heating and drying out the western U.S. and warming the tropical Atlantic Ocean – we are amplifying both of these phenomena as well.

“So when we happen to get a La Niña event, as this year, natural variability reinforces the impact that climate change is playing and we get dual disasters playing out in the U.S., as we are seeing right now,” Mann told USA TODAY.

The La Niña climate pattern is a natural cycle marked by cooler-than-average ocean water in the central Pacific Ocean. It’s one of the main drivers of weather in the U.S. and around the world, especially during the late fall, winter, and early spring.

Mann explained how the natural La Niña climate cycle is also having an impact:

“La Niña years tend to be associated with a Northern Hemisphere jet-stream pattern that favors both dry, warm conditions out West, and reduced vertical wind shear in the tropical Atlantic and Caribbean. The former favors wildfires out West, the latter favors hurricanes back East.”

Federal government forecasters from the National Oceanic and Atmospheric Administration announced La Niña’s formation last week. It’s expected to exacerbate both the hurricane and wildfire seasons.

In the West, climate scientists say rising heat and worsening droughts in California consistent with climate change have expanded what had been California’s autumn wildfire season to year-round, sparking bigger, deadlier and more frequent fires like the ones we’ve seen this year.

The role that climate change played in wildfires in California seeped into the political realm earlier this week. Though government officials and scientists identified climate change as the primary culprit behind the intense wildfires, President Donald Trump insisted during a briefing in Northern California on Monday that “forest management” is more to blame.

California Gov. Gavin Newsom, a Democrat, told him forest management is an issue, but “climate change is real, and that is exacerbating this.”

And as for hurricanes, scientists also say global warming is making the strongest of them, those with wind speeds of 110 mph or more, even stronger. Also, warmer air holds more moisture, making storms rainier, and rising seas from global warming make storm surges higher and more damaging.

During Hurricane Sally, a peak storm tide of 5.6 feet occurred Wednesday morning in Pensacola, Florida – the city’s third-highest level on record.

In addition, scientists have been seeing tropical storms and hurricanes slow down once they hit the United States by about 17% since 1900, and that gives them the opportunity to unload more rain over one place, as 2017’s Hurricane Harvey did in Houston – and what’s happening now with Hurricane Sally in the Southeast U.S.

This article was originally published on usatoday.com