In the weeks following the landfall of Typhoon Haiyan, the role of climate change has dominated public discourse. Is a changing climate to blame for the devastation? This is a weighty accusation, and one that forces us to re-examine our positions on climate action and related debates.
On November 8, Typhoon Haiyan hit the Philippines claiming 5,598 lives and displacing another 3.8 million. With winds of up to 195 mph, it was one of the strongest tropical cyclones ever recorded and, according to USAID, the US government has sent nearly $60 million in relief funds.
“Tropical cyclone,” “hurricane” and “typhoon” refer to the same type of storm. These systems generally form in waters warmer than 80 degrees, through a combination of warm surface water and air, low pressure and the force of the Earth’s rotation. Additionally, tropical cyclones are generally “triggered” by a thunderstorm or similar event—most of the Atlantic hurricanes that hit our east coast, for example, start out as thunderstorms on the west coast of Africa.
Recently some scientists have started investigating the possible effects of climate-warmed oceans on cyclones. One of these researchers is world-renowned atmospheric scientist Dr. Kerry Emanuel of MIT, who, incidentally, is currently on sabbatical here at Bowdoin.
According to Emanuel, contrived warming of tropical oceans will have two likely outcomes, neither of which should come as a comfort to us as East Coast dwellers. First, the average hurricane or typhoon will be more intense; and second, the “ceiling” on storm intensity will itself be raised.
Taken to extremes, Emanuel’s research indicates that, should ocean temperatures rise another 15 degrees Celsius, resultant instabilities in ocean-atmosphere processes could generate runaway hurricanes the size of entire continents. Emanuel has proposed that these hypothetical systems (which he calls “hypercanes,”) may once have, caused the sort of global mass extinction events that wiped out the dinosaurs.
It should be noted that greenhouse gas-driven climate warming is not the primary suggested trigger of hypercanes in Dr. Emanuel’s research. Rather, he and his colleagues suggest that underwater volcanoes or meteorite impact could generate the necessary heat to bring on a superstorm of that magnitude.
The good news? It’s unlikely that a biblical-scale hypercane will occur any time soon. Additionally, though climate models indicate that warmer ocean surface waters will likely increase the severity of future storms, the same studies have shown that the number of storms per year may either decrease or remain unchanged. However, some meteorologists (such as Dr. Jeff Masters, founder of the forecast website Weather Underground) have suggested that warming oceans may lengthen the hurricane season into late fall or early winter.
Given the emerging connection between intense storms and a warming planet, many environmental groups have used the situation in the Philippines as a rallying point for climate activism. The devastation caused by Typhoon Haiyan has inspired worldwide calls to action and hunger strikes, and even a candlelight vigil held by Green Bowdoin a few weeks ago to show solidarity with those affected by the storm.
Though warming oceans may indeed cause increases in tropical cyclone intensity, a direct causal link remains near impossible to conclusively prove. If If a definitive link could be found, it would hopefully mean a time of reckoning for governmental energy policies worldwide. The only appropriate response to such a discovery would be a two-pronged effort to reduce known drivers of climate change and protect vulnerable areas from damage. I can only hope that these types of findings continue to expose the not-so-hypothetical dangers of climate change denial.