Thursday, 14 December 2017

Hurricane Harvey’s Record Rains Were Made Much Worse by Climate Change

New Science Confirms that Harvey’s Record Rains Were Made Much Worse by Climate Change


13 December, 2017


Hurricane Harvey barreled into Texas on August 25th of 2017. Over the next six days, it dumped 52 inches of rain across parts of the state, resulted in 800,000 calls for water rescue, caused 80 souls to be lost, and inflicted over 190 billion dollars in damages.

Harvey was the most damaging storm ever to strike the U.S. It was more costly than Katrina and Sandy combined. And recent studies now show that this damage, in large part, was due to climate change’s influence over the storm.

(Harvey just prior to making landfall on the Southeast coast of Texas. Image source: NASA.)

According to base climatology, we can expect this kind of event to occur onceevery 9,000 years. But living in base climatology we are not. Due to fossil fuel burning, atmospheric CO2 levels are above 405 parts per million — levels not seen in at least the past 2.5 million years. Meanwhile, total greenhouse gas forcing (after you add in methane and other heat trapping gasses) is at levels not seen in around 15 million years. So we’re now in a world that’s pretty different from what we are used to. A more dangerous world.

How different and how much more dangerous is a measure of some debate. More to the point, the question of how much the presently serious alteration to the world’s climate impacts the world’s weather is a pretty hot topic. What we already know is that the weather is becoming more extreme, more damaging, and that the most intense storms and droughts are growing worse.

(Incidence of record breaking daily rainfall events are increasing as the Earth warms. New science is starting to attribute aspects of individual extreme events to human caused climate change. Image source: Increased Record Breaking Daily Rainfall Events Under Global Warming.)

But boiling it all down to a single storm like Harvey, how much can you blame on climate change? Well, that’s starting to become clearer thanks to a pair of new scientific studies.

According to a recent study in the Geophysical Research Letters, human-caused climate change increased Harvey’s devastating rainfall intensity by at least 19 percent and likely by around 38 percent. Enough of a human caused influence both to tip the scales between a relatively rough event and an epic deluge for the history books. Meanwhile, another study led by World Weather Attribution, found that Harvey wasalso three times more likely to have formed in the presenthuman-altered climate.

If these peer-reviewed studies are correct, their findings point toward a rather stunning conclusion — the storm was much more likely to form due to climate change and the storm was made much more intense after it formed due to climate change.

In essence, the new science finds that climate change’s influence finger prints are all over Harvey’s devastating impact. Folks around the world take note. Your severe weather has been hyper-charged.

CREDITS:

Hat tip to Eleggua



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