Climate change is even worse than we thought, the Washington Post wrote Wednesday. Millions, it turns out, could be washed away in annual floods now feared for seaside cities.
“Scientists triple their estimates of the number of people threatened by rising seas,” read the headline on Chris Mooney’s piece Wednesday on the Washington Post website. “150 million people could live below the high tide line by 2050, new research finds.”
But despite the first part of the first sentence – “Rising seas will be much worse and more expensive to deal with than previously thought, new research finds,” Mooney wrote – this story is not about global warming so much as measuring devices.
The reason for the increased cost estimates is “not because of faster changes in sea levels but because of an increase in estimates of the number of people living on low ground,” Mooney wrote.
Yet, Mooney wrote: “The upshot of the study is that 110 million people worldwide live below the high-tide level – including many partly protected by sea walls or other infrastructure, as in New Orleans. Even under a scenario of very modest climate change, that number will rise to 150 million in 2050 and 190 million by 2100.”
If worst-case scenarios are realized, “as many as 340 million people living below the high-tide level could be in peril, to say nothing of how many could be affected by floods and extreme events,” Mooney wrote. “Such figures are three times – or more – higher than earlier estimates.”
This comment is curious from the start – what a 5-inch-per-century rise in sea levels would cause by floods or extreme events to increase in frequency is not stated.
It becomes even more curious a few paragraphs later when Mooney wrote: “The reason for the big change is that prior research has relied on data about coastal elevations that comes from radar measurements from the 2000 space shuttle Endeavor mission. But that data set has problems. The instrument detected the height not only of the coastal land surface but anything else that was on it, such as houses and trees. This introduced errors in land-elevation estimates averaging about 6 ½ feet globally, the new study says.”
Now, some countries use laser-based coastal measurements to “gain more accuracy,” and the new estimates were produced by “training an algorithm to apply similar adjustments to the global data set from the space shuttle.”
The algorithm has been “trained” to produce far more dramatic results. The estimates of people living below the current high-tide level went from 28 million worldwide to 110 million now, and the number of people who “fall below the level for the worst yearly flood” went up from 65 million to 250 million, Mooney wrote.
These estimates are based on world temperatures increasing 3.6 degrees by 2100, “the temperature rise that world leaders have set as an absolute limit,” Mooney wrote. And that is bad because “the world is on course to warm considerably more than 2 degrees Celsius … so there are more dire scenarios. … If key instabilities kick in in Antarctica, 480 million people would be exposed to an annual flood in 2100.”
Fortunately, temperatures have barely moved since 1995, and the Earth has cooled nearly a half-degree in the three years Donald Trump has served as president – the fastest rate of cooling in a century – and even global warming promoters such as Gavin Newsom and James Hanson say another 8-10 years of pause could be in store.
That coupled with the decrease in sea level rise mean the dangers of global warming might even be decreasing.