Climate change and Harvey
Has climate change just cost a President who denies its existence $1 million personally, and his country a possible $100 billion?
Possibly. It’s hard to definitively point to mathematics, statistics and measurements which can say that this much pollution caused this much rainfall, much to the satisfaction of endlessly pedantic climate change deniers.
As people left their homes and their possessions on life rafts, makeshift boats and winches from emergency helicopters, it’s hard to imagine that any American could have watched those scenes without wondering what could be done to prevent it happening again.
According to the US President, currently (perhaps struggling) to count the cost of one of the worst natural disasters in decades, reducing Co2 emissions would have done nothing. Evidence is shaky and incomplete, he contends, and withdrawing from the Paris climate change agreement would have no effect on whether future generations would be cursing us for leaving them in an uninhabitable wasteland.
For those who believe in the existence of a higher power it’s tempting to believe, that having witnessed such buffoonery and outright denial of facts, the lord himself didn’t decide to prove Trump wrong within months by visiting a flood upon him.
Despite the denials of old white men in Washington, conveniently miles away from where the hurricane, and possible future hurricanes may arrive, many are resolute in their conviction that Harvey was, if not created, worsened by climate change.
First of all, some facts. As reported by the Rolling Stone, Harvey is the worst rainfall event ever in the continental U.S. More than 50 inches of rain deluged parts of Houston. The amount of water that poured from the sky is difficult to conceptualize. By some estimates, 19 trillion gallons of water fell in five days. That's roughly a million gallons of water for every person in southeastern Texas. Harvey's economic toll will likely exceed Katrina as the most expensive disaster in American history.
Michael E Mann, distinguished professor of atmospheric science at Pennsylvania State University and director of the Penn State Earth System Science Centre, wrote an opinion piece pointing to some of the effects of climate change that almost certainly had a hand in the hurricane.
Mann wrote that sea level rise attributable to climate change – some of which is due to coastal subsidence caused by human disturbance such as oil drilling – is more than half a foot (15cm) over the past few decades. That means the storm surge was half a foot higher than it would have been just decades ago, meaning far more flooding and destruction.
In addition to that, sea surface temperatures in the region have risen about 0.5C (close to 1F) over the past few decades from roughly 30C (86F) to 30.5C (87F), which contributed to the very warm sea surface temperatures (30.5-31C, or 87-88F).
Further to this, though, is the effect that rising temperatures are having in the areas that include Houston, Texas and other areas at risk from severe weather.
Mann states that there is a simple thermodynamic relationship known as the Clausius-Clapeyron equation. This tells us there is a roughly 3% increase in average atmospheric moisture content for each 0.5C of warming. Sea surface temperatures in the area where Harvey intensified were 0.5-1C warmer than current-day average temperatures, which translates to 1-1.5C warmer than “average” temperatures a few decades ago. That means 3-5% more moisture in the atmosphere.
Now, of course, it’s very easy and simple to quote scientifically renowned professors of academia from world renowned universities, but purely for balance, and to avoid being labelled ‘fake news’, we should also provide you with Donald Trump’s opinion on climate change, which was said in 2015.
"I'm not a believer in man-made global warming. It could be warming, and it's going to start to cool at some point. And you know, in the early, in the 1920s, people talked about global cooling...They thought the Earth was cooling. Now, it's global warming...But the problem we have, and if you look at our energy costs, and all of the things that we're doing to solve a problem that I don't think in any major fashion exists."
We’ll leave it to our readers to wade through the mountains of scientific evidence presented by both sides and make a decision on their own as to whether they believe that a hurricane which delivered the most rainfall in recorded US history was in any way affected by climate change.