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| Well regarded climate scientist James Hansen has done climate research and the results are very frightening. How seriously should we take this work? |
He actually released a draft of the study about a year ago. But it has since been peer reviewed, giving it much more - but not complete - credence.
Hansen says the team of researchers he led concluded that the sea levels would rise by six to 15 feet by the end of this century, which is as much as 10 times faster than most scientists up until now have been predicting.
Hansen also says climate change will, this century, create frequent, huge storms, like Superstorm Sandy writ large. These storms would largely spin up in the mid-latitudes, were most of us live.
Some publications have been comparing Hansen's scenario to a "Day After Tomorrow" movie style climate apocalypse, but I definitely wouldn't go that far.
WHAT HANSEN SAYS
Like most scientific studies done by very smart people like Hansen, this latest one is a pretty technical.
Basically, though, he's saying that rapid melting now underway from ice caps in places like Greenland and Antarctica will get even faster.
In a New York Times article about Hansens research, the paper reports that fresh water from the melting ice caps would flow into the oceans. That would slow down or maybe even stop some of the vast ocean currents that redistribute heat around the planet so that there aren't terrible imbalances between hot and cold regions of the world.
The colder water coming off the melting ice caps would also cause warmer water to sink further down, which would melt the ice caps from below, making all the melting faster. This "positive feedback" would make everything even worse.
Tthe ocean currents that would normally pump excess heat to the north where it dissipates. If the ocean currents weaken or disappear, something else would have to take over to stop the imbalance a too-wide difference in temperature between the tropics and poles.
Storms do that now, and always have, with or without climate change. But if the imbalance is bigger, you'd need bigger storms to correct the imbalance. You'd get incredibly huge storms, ones like immense tempests that happened 120,000 years ago, when the world warmed due to natural processes.
Some scientists see signs that the slowdown in ocean currents has already begun due to global warming and melting ice caps.
For instance, 2014 and 2015 were the warmest years on record for the Earth as a whole, at least since reliable records got going in the late 1800s.
But during this time, there's been a persistent patch of very chilly water and air in the North Atlantic, not far from Iceland. It's believed this might be caused by meltwater flowing into this region's waters from Greenland, and the slowing of a massive northeastward flowing warm ocean current that parallels the North American coastline and heads toward northern Europe.
OTHER SCIENTISTS REACT
Scientists who reviewed Hansen's work during its peer review process said the latest draft is much improved over last year's draft, and the results are plausible.
However, as Slate notes, this is only one study, and we'd want a lot of other scientists to take more, even deeper looks at the melting glaciers, the ocean currents and everything else to see whether Hansen's dire warnings make sense.
Many climate scientists are cautious about Hansen's study. As the Washington Post reported, Michael Mann, a Pennsylvania State University climate scientist who isn't exactly shy about warning about the consequences of climate change, is hesitant about Hansen's work.
Mann wonders whether Hansen's research overestimates the amount of meltwater flowing into the oceans from the thawing glaciers, and questions whether Hansen fears that the ocean curents could slow or stop are overblown.
Still, as Mann and many other climate scientists note, Hansen has a history of being particularly precient about climate change in the past.
Hansen, a former NASA scientist is most famous for telling a Congressional committee in 1988 about the threats from climate change, and that, probably more than anything else, put global warming front and center in national and international discourse.
All this debate over Hansen's research is one of the frustrating things about climate change science. Every serious scientist acknowledges human-induced warming is occuring. But there's still considerable debate over exactly how this will unfold in the future.
That's to be expected. Even the smartest scientists can't with 100 percent accurate predict the future. But they can keep studying, and maybe this will confirm or deny Hansen's scary research. Even if this further work doesn't give us clear answers on this, it will increase our knowledge about the upcoming effects of climate change.
More knowledge is precisely what we need.
ast summer, James Hansen—the pioneer of modern climate science—pieced together a research-based revelation: a little-known feedback cycle between the oceans and massive ice sheets in Antarctica and Greenland might have already jump-started an exponential surge of sea levels. That would mean huge levels of sea level rise will happen sooner—much sooner than expected. Hansen’s best estimate was 2 to 5 meters (6–15 feet) by the end of the century: five to 10 times faster than mainstream science has heretofore predicted.
The result was so important that Hansen didn’t want to wait. So he called a press conference and distributed a draft of his findings before they could be peer-reviewed—a very nontraditional approach for a study with such far-reaching consequence. Now, after months of intense and uncharacteristically public scrutiny by the scientific community, the findings by Hansen and his 18 co-authors have passed formal peer review and were published Tuesday in the journal Atmospheric Chemistry and Physics.
That’s bad news for those of us rooting for a stable planet. With Hansen’s paper now through peer review, its dire conclusions are difficult to ignore. And the scientific community, many of whom were initially wary of Hansen’s paper when it came out this summer, is starting to take serious note.
In an email to Slate, Ruth Mottram, a climate scientist who was skeptical of the initial draft, calls the final study “considerably improved.” Mottram, who specializes in studying the Greenland ice sheet, said “the scenario they sketch out is implausible, though perhaps not impossible … it’s frankly terrifying.”
Richard Alley, a key figure in the polar research community, also gave the Hansen study cautious praise. “It usefully reminds us that large and rapid changes are possible,” Alley said in an email, and that “uncertainties are clearly loaded on the “bad” side.” Alley stressed, though, that the Hansen result was only a single study, and wasn’t detailed enough to be used as a firm prediction.
Hansen and his co-authors describe a world that may quickly start to spin out of control if humans keep burning fossil fuels at close to our current rate. “It is not difficult to imagine that conflicts arising from forced migrations and economic collapse might make the planet ungovernable, threatening the fabric of civilization,” the study reads. And given the assumed accelerated pace of melting, all this could happen just decades from now, not centuries.
The world Hansen and his colleagues describe reads like a sci-fi plot synopsis—and it’s now officially part of the scientific canon (though peer review doesn’t necessarily guarantee that a paper is infallible). If Hansen and his colleagues are correct, this paper is likely one of the most important scientific contributions in history—and a stark warning to world governments to speed up the transition to carbon-free energy.
Hansen recorded a State of the Union response-style video address to accompany the paper, and, hoo boy, don’t watch it if you were hoping to have an upbeat day (it is also somewhat technical):
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