Human-Caused Climate Change Could Doom Coastal Cities, Neil Tyson Says

The United States "might not be able to recover" from climate change if extreme weather events and flooding continue to swamp the country's largest coastal cities, astrophysicist Neil deGrasse Tyson told CNN yesterday (Sept. 17).

In an interview with reporter and TV host Fareed Zakaria on CNN's "GPS," Tyson discussed hurricanes Harvey and Irma, which dumped rain and brought heavy winds and storm surges to Texas and Florida, respectively.

When asked about Homeland Security Adviser Tom Bossert's response to the hurricanes — that is, declining to say whether climate change had intensified the storms — Tyson lost his patience. [Hurricane Harvey Before and After: Satellite Images Show Storm's Destruction]

"Fifty inches of rain in Houston!" Tyson said, according to CNN. "This is a shot across our bow, a hurricane the width of Florida going up the center of Florida!"

Research shows that human-caused climate change can make storms more extreme than they would be otherwise, Live Science reported previously. But humankind has been slow to curb the emission of greenhouse gases, such as carbon dioxide, Tyson said, adding that the longer people take to respond to climate change, the bleaker the outcome for humanity gets.

"I worry that we might not be able to recover from this, because all our greatest cities are on the oceans and water's edges, historically for commerce and transportation," Tyson said on CNN.

These cities will be the first to go as water levels rise, Tyson said. "And we don't have a system — we don't have a civilization with the capacity to pick up a city and move it inland 20 miles [32 kilometers]," he said. "This is happening faster than our ability to respond. That could have huge economic consequences."

Expert response

Tyson's assessment of climate change's role in intensifying the recent hurricanes is spot-on, said Michael Mann, a distinguished professor of meteorology at Pennsylvania State University.

"There are theoretical reasons to expect that the strongest storms will increase in intensity as sea-surface temperatures increase, and this is indeed being observed," Mann told Live Science in an email.

For instance, for every 1 degree Fahrenheit (0.56 degrees Celsius) of ocean warming, there has been about a 10 mph (16 km/h) increase in maximum sustained winds among Category 4 and Category 5 hurricanes, Mann said.

This is bad news for coastal cities: These faster winds correspond to a roughly 20 percent increase in wind damage, Mann said.

Human-caused climate change has heated not only the land but also the ocean, Live Science previously reported. Warmer oceans have consequences — "a warmer ocean surface means more moisture content and more rainfall with these storms, and global sea-level rise has increased the coastal flooding associated with these storms," Mann said.

If people don't do enough to reduce greenhouse gas emissions and the Earth continues to warm, "then I do believe that we are talking about a situation where we will literally be retreating from the coastline and relocating the major coastal cities of the world — a daunting and extremely expensive proposition," Mann said.

Other researchers say there is a strong link between Hurricane Harvey's extreme rainfall and climate change; heavy-precipitation events have increased in recent decades, and several were shown to be more likely because of climate change, Live Science previously reported.

Original article on Live Science.