As Hurricane Harvey continues to wreak havoc in Texas, many climatologists were quick to jump on the bandwagon that climate change caused this disaster.
The key here is that climate change did not ’cause’ it, but it certainly played a part.
Talking about climate change can always be risky during such a disaster, as it would be viewed as insensitive. A lot of the damage that Harvey did would have occurred even without climate change but it would be irresponsible if we did not talk about climate change because as the US military puts it, it’s a threat multiplier.
However, thanks to recent plethora of great climate journalists and communicators, it’s easy to see how climate change made Hurricane Harvey worse. The best source of this is a Facebook post by Michael Mann which explained how climate change made Hurricane Harvey worse in 3 ways.
Firstly, it raised sea levels more than half a foot in recent decades which means more storm surges.
Secondly, it raised the temperature of the water in the region, which means more evaporation and more water in the air as Mann explained:
“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 the ‘average’ temperatures a few decades ago. That means 3-5% more moisture in the atmosphere.”
Finally, the most damaging aspect of Hurricane Harvey is how it’s hanging around in one place, thanks to weak prevailing winds. Mann recently published a paper suggesting that such near-stationery summer weather patterns are made more common by climate change.
This stalling is one of the reasons Harvey has become so dangerous: It’s expected to stay in the area for days, blasting the region with literally feet of rainfall.
“In conclusion, while we cannot say climate change ‘caused’ Hurricane Harvey (that is an ill-posed question), we can say that it exacerbates several characteristics of the storm in a way that greatly increased the risk of damage and loss of life,” Mann wrote.
Again, exactly how much climate change contributed to this damaged will have to await peer-reviewed attribution science, but logic, experience, and measurements make it clear that Harvey’s damage was worse than it would have been absent recent changes in the climate.