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2009-03-23, 21:27 "Bangladesh is set to disappear under the waves by the end of the century" read the headline in the Independent, a U.K. newspaper.
 | | Life in Noakhali, on Bangladesh's coast |
Really? I visited Bangladesh a couple of times recently and thought about this article. It's eerie to travel for hours along bumpy roads, past dense rice fields that support millions of people, and think that this could all be gone in my lifetime.
Fortunately for them, the situation isn't so dire. Don't get me wrong; I'm no climate change denier. It's just that the author of the article above, Johann Hari, seems to have made a basic mistake.
He claims that James Hansen, the famed NASA climate scientist, "believes the melting of the Greenland ice cap being picked up by his satellites today, now, suggests we are facing a 25-metre rise in sea levels this century."
Never mind that Hansen doesn't own any satellites, and is a climate modeler. His specialty is not analyzing satellite data. But also think about it—25 meters. For those of you not familiar with the metric system, or who are numerically challenged, 25 meters is huge. I live in an apartment building near the ocean, on the twelfth floor. If the seas climbed that high, they'd reach about the eighth floor of my building.
In contrast, the numbers that most researchers are talking about are one or two meters of sea-level rise by 2100. (The range comes partly because scientists don't fully understand how glaciers and ice sheets will melt and fracture with more warming, and partly because they don't know how much greenhouse gases people will emit.)
Hansen himself has said that the record of ancient climate change "contains numerous examples of ice sheets yielding a sea level rise of several meters per century." Granted, that came when the planet had much more ice on it than today, so there was more to melt. On the other hand, it seems we're warming the climate far faster than it did at the end of the last ice age.
Tellingly, Johann Hari's article didn't include any direct quote from Hansen. I think he simply misunderstood (or misheard) Hansen. Sea levels could rise by 25 meters or more if we keep the level of the greenhouse gas CO2 as high as they are today, Hansen has said. But this would probably take many hundreds or even a few thousand years; I know of no credible scientists who have said this it's remotely plausible that this could happen this century. Bangladeshi-Canadian climate scientist Monirul Qader Mirza does an admirable job of clearing things up, in his article "Would Bangladesh really disappear under water by 2100?"
Anyway, Hari writes that 25 meters of sea-level rise "would drown Bangladesh entirely." (That part is basically true; it's a low-lying country, nearly all delta.) "When I heard this, I knew I had to go, and see," he says.
But why not stay at home to report the story? Twenty-five meters of sea-level rise would swamp the Independent's offices in London, along with a lot of other cities in the world. The Netherlands would certainly be underwater; it's hard to imagine them building dykes high enough to deal with that. To see what 13 meters of sea-level rise would look like in London, check out this interactive map. (It would only go up to 13 meters, because anything beyond that is science fiction.)
OK, so I've probably convinced you by now that Hari made a mistake. The problem is, it keeps getting repeated. The Times of London carried an article saying: "Professor James Hansen... goes even further, predicting a sea level rise of up to 25 metres by 2100, which would completely submerge Bangladesh." IRIN, a UN news service, wrote in an article that got picked up and reprinted a bunch of times: "James Hansen... went so far as to predict that with a 25m rise in sea levels, the entire country could well sink by 2100." And the AFP said: "James Hansen... says Bangladesh's entire 144 million population will become environmental refugees by the end of the century."
If these wordings seem remarkably similar to each other, I think it's because these other articles borrowed from Hari's, or from each other, without ever talking to Hansen or checking their facts. And then The Huffington Post reprinted Hari's article in November, months after it was originally published, and it still has the 25-meter figure in there.
These kinds of basic errors and exaggerations are all too common in climate change reporting—especially when reporters parachute in to Bangladesh, "ground zero for climate change," it's often called—and don't understand how things work there. A 2007 Chicago Tribune article, for instance, said: "On Bangladesh's southern coast, erosion driven in part by accelerating glacier melt and unusually intense rains already has scoured away half of Bhola Island." You might think it would be nearly gone by now. But I went there in November; it's still around. As shown in this map (at left) I got from a Bangladeshi researcher, Bhola has actually lost about 10 percent or so of its area over 30 years. But this is mostly because of a natural process, where some land gets eroded away and other land forms anew. Bangladesh is a vast delta, the mouth of one of the world's largest river systems, and the islands at this mouth have been shifting like this for hundreds of years.
Last year, reporters got confused by this issue of land that's being added by accretion of silt. One story claimed: "New data shows that Bangladesh's landmass is increasing,
contradicting forecasts that the South Asian nation will be under the
waves by the end of the century, experts say." But there's no contradiction here.
As the latest IPCC report shows, nearly all the mega-deltas in Asia are growing. (See the second section of the report, Chapter 10 on Asia, page 496; you can also download that page from my site (28 kb pdf).) China's Huanghe-Huaihe delta is growing faster than Bangladesh's. But this doesn't disprove climate change, or sea-level rise. The new land that is getting added is low-lying, and will get swamped by sea-level rise as it accelerates over the coming century (as it likely will, even if we stopped burning fossil fuels tomorrow, because the greenhouse gases we've already emitted will continue heating the planet). OK, enough complaining for now. I just finished writing a column for the Columbia Journalism Review complaining about other climate change coverage. |
