CLEVELAND, Ohio -- As recovery efforts continue after Hurricane Harvey dumped more than 20 trillion gallons of rain on Texas and Louisiana, across the globe, heavy rains crippled India, Bangladesh and Nepal this week, killing more than 1,200.
While Harvey's rain was an unprecedented 1,000-year flood event, indicating a 1 in 1,000 chance of that intense of a flood occurring in any year, the flooding in southeast Asia is considered much less out of the norm, with regular floods during monsoon season, running from June to September.
First, Harvey.
Hurricane Harvey made landfall as a Category 4, devastating Houston and surrounding areas with over 50 inches of rain, breaking the all-time record for rainfall by a single storm system in the lower 48. Over 93,000 homes were estimated to be destroyed, says the Texas Division of Emergency Management, with over 32,000 stranded in shelters. 325,000 Texans have already registered for assistance from FEMA, as 80 percent of Texans are uninsured for floods. Shane Hubbard, Ph.D. researcher with the space science and engineering center at the University of Wisconsin-Madison told the Washington Post, "In looking at many of these events [in the United States], I've never seen anything of this magnitude or size," he said. "This is something that hasn't happened in our modern era of observations."
Harvey quickly made it into the history books in the U.S., with the latest death toll up to at least 47.
Parallel flooding in southeast Asia.
Southeast Asia, specifically India, are no strangers to this extreme type of flood event, yet this year's floods are still particularly severe. Over the past week, lives were lost as the rain triggered destructive landslides, while locals in other areas "waded through waist-high water trying to get home from work after being stuck there overnight," described USA Today.
The BBC reported 16 million people have been affected across south Asia, with tens of thousands displaced.
The link to climate change.
Headlines surrounding devastating flood damage like during Harvey and southeast Asia's monsoon could become more of the norm with climate change.
No, climate change did not on its own cause the hurricanes and floods. Instead, scientists hypothesize the link is intensity. "Global warming is making a bad situation worse," says the Atlantic. First, the releasing of excess greenhouse gases from human activities prevents solar radiation from bouncing back into space, inadvertently trapping in heat and increasing global temperatures. With warmer air, comes more moisture in the atmosphere, and with more moisture comes heavier rainfall. As the air warms, the ocean does too, allowing Harvey, and tropical cyclones in general, to feed off of it as fuel. Sea-surface temperatures near Texas rose between 2.7 to 7.2 degrees above average as Harvey neared, allowing it to grow from a tropical depression to a Category 4 hurricane in about 48 hours.
"This is the main fuel for the storm," said Kevin Trenberth, a senior scientist at the U.S. National Center for Atmospheric Research, to the Atlantic. "Although these storms occur naturally, the storm is apt to be more intense, maybe a bit bigger, longer-lasting, and with much heavier rainfalls [because of that ocean heat]."
Trenberth believes the human contribution can be up to 30 percent or so of the total rainfall coming out of a storm. In Harvey's perspective, that's over 6 trillion gallons.
Generally speaking, human-induced warming by the end of the 21st century will likely cause tropical cyclones globally to be more intense on average, by 2 to 11 percent, and this change would imply an even larger percentage increase in the destructive potential per storm, concluded the Geophysical Fluid Dynamics Laboratory with NOAA. "There are even better odds that anthropogenic warming over the next century will lead to an increase in the occurrence of very intense tropical cyclones in some basins -- an increase that would be substantially larger in percentage terms."
With climate change and global warming temperatures, double flood disasters will likely increase in occurrence.
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Kelly Reardon is cleveland.com's meteorologist. Please follow me on Facebook and Twitter @KelTellsWeather.