Saturday, June 10, 2006

An Inconvenient Triumph: Climate Change and the Indian Subcontinent

I just saw An Inconvenient Truth and I think it's beautifully done -- I would strongly recommend it. Even if you don't love Al Gore as a politician, the science is convincing and all the pictures of vanishing glaciers and dried-up inland lakes (Lake Chad!; the Aral Sea!) are terrifying.

In the film, Gore refers several times to the potential catastrophic consequences of Global Warming in the Indian subcontinent. It's somewhat ironic, because countries on the Indian subcontinent are far smaller contributors of greenhouse gases than the developed countries (India's per capita emissions are one sixth the world average) but you can be sure that the subcontinent will feel its effects. As I understand it, there are two major consequences of global warming for the Indian subcontinent that are essentially guarantees, and a third which seems to me to be a maybe:

First guarantee: significant amounts of land in the Bay of Bengal are going to disappear if oceans rise even 1 foot, as is predicted to occur in the next 50 years. Most estimates I've found give the number at about 15% of the total landmass of Bangladesh, with a comparable loss of land in West Bengal on the Indian side. As many as 60 million people will be displaced in both countries.

In Orissa, the receding coastline is already a fact of life. In the Satabhaya region of the Orissa coastline, according to this article, the shore has moved 2.5 km inland over the past 25 years, displacing a number of villages. And it continues to move. (The article doesn't specify what could be causing the rising sea levels in that specific part of the state.)

In the short run, scientists are already noting a pattern of a growing number of low pressure systems (leading to cyclones) in the Bay of Bengal in the post-Monsoon season. These are expected to worsen -- meaning that extreme storms may force mass evacuations of coastal regions well before the land itself disappears. (See this article for more.) Also, erosion caused by the storms is already seriously affecting these regions. As Banglapedia puts it:

Flooding and erosion/sedimentation Bangladesh experiences moderate to severe flooding every year. Frequent storm surges also cause severe coastal flooding. The flood situation is further aggravated by the high tide in the Bay of Bengal. It has been seen with a 1.4m rise in sea level water level rises to about 6m near the meghna estuary. Even with a 0.2m rise in sea level, water level rises between 4.5 and 5m near the estuary. Since most of the coastal area is below 1.5m above mean sea level (MSL) and the area near the confluence of the ganges and Meghna is below 3m above MSL, both depth and area of inundation will increase extensively. However, the water level in the Ganges and Upper Meghna also increases significantly due to backwater effect as a result of changes in the hydrodynamics of flow. Hence the severity and extent of flooding will increase even in the upstream portion of the river. On the other hand, a rise in sea level will also move the shoreline landward and this will result in loss of farmland, leading to the shifting of agriculture, reduced crop yields, and loss of cultivable areas. Increased flooding will cause problems with existing irrigation and drainage system too. (link)

Even small changes in the mean sea level could lead to a cascade of problems for the Bengal delta, because the water systems are all interdependent. Even before the land disappears, the damage caused by increased flooding is expected to make a lot of coastal land essentially uninhabitable.

Tyler Cowen, when he was in India a couple of years ago, did a thought experiment on this. It's a little in the "heartless economist" vein, but it's worth reading.

And here's a Salon article about attempts that are being made in Bangladesh to raise awareness about the coming catastrophe.

The second guarantee: The glaciers will disappear, leaving all of the subcontinent's major rivers dry. Abhi already posted on this last fall, though he didn't get much of a response to this shocking fact at the time. These rivers, as everyone knows, provide the vast majority of water to India, Pakistan, Nepal, and Bangladesh. (And glacial water also feeds China; in total, 40 percent of the world's population is dependent on water from the Himalayas.) The retreat of the Himalayan glaciers is not a prediction; it's happening. The only question is when the effects will start to kick in. But I would say that even if it takes 100 years for the water supply to crash, it's not to early to start doing something about it.

But here's the irony: in the short run, the rapidly melting glaciers may actually cause flooding in the plains.

The third "maybe" consequence is that the whole weather pattern could change if ocean currents change as a result of rising water temperatures. The monsoon could disappear entirely (or it could double in intensity!). There's not much to say about this -- because no one really knows -- except that it reminds us how little we really know about what is happening.

In An Inconvenient Truth Gore talks about an instance where scientists were surprised by the rapidity of change. In Antarctica, in 2002, the Larsen ice shelf collapsed over the course of a few weeks. No one predicted that a chunk of solid ice the size of Rhode Island could break up so fast. But now scientists think it was probably caused by earlier partial melting, leading to the creation of 'moulins' under the ice, that exponentially speed up the break-up of ice shelves. Those same moulins are being observed in Greenland, suggesting that large melt-offs may be imminent there too.

In effect, the predictions for ocean level rise over the next fifty years may be understatements: it could be much sooner than that. Scientists have been unpleasantly surprised by things like this before, and may be again.

[Cross-posted at Sepia Mutiny]


Krish said...

Excellant article. However, I do not agree with your statement that India's contribution of greenhouse gases is smaller compared to world average. the only data we have from India is dated back to 1994 when only the elite had cars and many in the middle class were riding on bicycles. Even then, it was 5th largest contributor of greenhouse gases. With the advent of new economy, anyone with a job is driving a car and people without even a job and many rural people drive two wheelers. Under such a scenario, I am sure the contribution is significant. I wouldn't be surprised if we are third behind US and China. It is high time Indians take note of the consequences of Greenhouse gases and think about the way they drive.

Once again, I want to say that it is a nice post.

6:19 PM  
Ruchira Paul said...

Krish's point is well taken. In countries like China and India, the sheer number of people participating in even minor polluting activities, adds up to a lot. In the last three years, the noxious diesel fumes in Delhi have been brought under control by commercial vehicles switching over to natural gas fuel. But private cars running on gasoline (petrol) are increasing by the day. Still Delhi air is now far better to breathe. There is no doubt that Asian countries are fast catching up with industrial polluters in the western hemisphere. Here is a link to a study that shows the extent of the damage to the atmosphere above China and India.
(couldn't link to the pdf file ). The Asian pollution apparently is also richer in particulate matter which interferes with the weather pattern above Bay of Bengal and the Indian Ocean. I have no doubt in my mind that Al Gore and the environmental scientists' alarm bell is legitimate - no matter what Bush and his right wing corporate buddies would have us believe. The hopeful sign is that the latter group is now losing the war of credibility in the public's mind.

Al Gore will hopefully run for the 2008 Democratic nomination. As of now, I see no one on the horizon who has his pristine record on Iraq and a substantial public service credential such as his pro-environmental work. When not mummified by the handlers, he is funny and comfortable in his skin. His two boffo SNL appearances testify to his sense of humor and his recent speeches, to his intelligence and grasp on policy. "Gore - Edwards" sounds like a dream team. But will it happen? Who knows? Dems have a way of breaking my heart.

8:23 PM  
Mahmud said...

Amardeep, good post. Besides the relative responsibility of countries in contributing to global warming, there is of course the issue of the consequences. What will happen if the Bengal delta loses 15% of its landmass? Where will the people go? I alluded to this problem in one of my blog posts earlier this year. You can find it here.

11:11 PM  
Anonymous said...

do read "State of Fear" by Michael Crichton for a different perspective on global warming and rising sea level.

4:30 AM  
Amardeep said...

Krish, Thanks -- that's an important point. Perhaps I should have said, "South Asian countries have historically been small contributors to greenhouse gases."

As we go forward, everyone will have to contribute to fighting this problem.

Ruchira, thanks for the link. I'd heard about the "brown cloud," but thus far it hasn't seemed to cause serious problems for the monsoon in particular -- probably only a matter of time, though.

And actually, if I were Al Gore I wouldn't run again! He's a rockstar in the 'professor mode' (as in this film), but I think he wasn't very effective on the campaign trail. We'll see, though: I think this film is going to be a big hit, which might change the political calculus a bit.

8:54 AM  
ana beynaam said...

gore keeps insisting that he will not run. . . his appearance on the tonight show was much like a rockstar, but he insists he wants to devote more time to this cause than to running for president. d'you think he's just protesting too much?

look forward to watching the documentary. i may have to wait for it to appear on DVD.

9:01 PM  
Mahesh said...

amardeep, another brilliant article!!!

i was wondering if u or ur readers know about the relative contributions of cars, aeroplanes and electricity generation to the total greenhouse gas emissions. i was under the impression that aeroplanes and coal power plants were the really big pollutors despite the fact that living in cities we tend to notice cars more than anything. after all, flicking a switch or snoozing on a flight we are not beset by fumes etc.

5:54 AM  
Amardeep said...

Mahesh, check out Wikipedia on this subject. It suggests that emissions from cars is actually pretty significant -- 20% of total greenhouse gases.

The energy industry counts for another 30%. So reducing our energy consumption isn't unimportant.

9:55 AM  
Archana said...

Great post, Amardeep! As usual, the catastropic environmental consequences of waste and pollution will affect the poorest citizens of the subcontinent the most - robbing them of their homes and way of life far before those of us in more privileged positions feel the consequences. It reminds me of the Tehri and Narmada Dam Projects.

10:38 AM  
Swapna said...

Well-written post !

6:18 PM  
Vivek Kumar said...

Thanks a lot for a very informative post.

I am going to use it for a discussion tomorrow.


4:35 PM  
Chandra said...

Actually the cause for global warming is a pretty one-sided debate. People who question the plug factor - that human activity is the cause for warming - rather than natural earth temperature cycles may be causing the raise in temperature are pretty much shut out from receiving funds and publishing papers in well known science journals.

See MIT's Atmospheric Science Professor Richard Lindzen's op-ed in Wall Street Journal in April 2006:

"Sadly, this is only the tip of a non-melting iceberg. In Europe, Henk Tennekes was dismissed as research director of the Royal Dutch Meteorological Society after questioning the scientific underpinnings of global warming. Aksel Winn-Nielsen, former director of the U.N.'s World Meteorological Organization, was tarred by Bert Bolin, first head of the IPCC, as a tool of the coal industry for questioning climate alarmism. Respected Italian professors Alfonso Sutera and Antonio Speranza disappeared from the debate in 1991, apparently losing climate-research funding for raising questions.

"...At Science and Nature, such papers are commonly refused without review as being without interest. However, even when such papers are published, standards shift. When I, with some colleagues at NASA, attempted to determine how clouds behave under varying temperatures, we discovered what we called an "Iris Effect," wherein upper-level cirrus clouds contracted with increased temperature, providing a very strong negative climate feedback sufficient to greatly reduce the response to increasing CO2. Normally, criticism of papers appears in the form of letters to the journal to which the original authors can respond immediately. However, in this case (and others) a flurry of hastily prepared papers appeared, claiming errors in our study, with our responses delayed months and longer. The delay permitted our paper to be commonly referred to as "discredited." "

Al Gore said in that Jay Leno show that there was not one published paper that refutes global warming phenomenon. No wonder!

The only crude opposition is from oil companies and they are fighting the self evident warming itself.

I read a while ago that global cooling was all the rage in the 50s and 60s; and they had physical and scientific proof then too.

Eliminating pollution, costing $100s of billions, may not stop the global warming if it's part of the earth's natural temperature cycle. We, nonetheless, need less pollution and less oil dependent economy, for health and geopolitical (Tom Friedman's geo-green) reasons. But then there is less cause for alarm - a big no no for the environmentalist drivers.

As Mahmud says, we may be better of spending the $100s of billions on the consequences, in Bangladesh, in east African countries, and elsewhere, rather than trying to eliminate the, probably, unstoppable warming of the planet in the near term.

1:05 PM  
meninder purewal said...

global weather patterns are EXTREMELY complex. global warming is a definite and serious threat, but playing out all the circumstances is getting to be a bit... well, annoying. the point is, we should be concerned. however, because of the complexity and numerous variables, the largest computers in the universe and the best scientists will never be able to predict the actual sequence of events (all they get is the number 42). so, why do we go on about it? probably because it's what will get the lay people motivated to take action. as a scientist myself, i find this speculation of the global warming scenarios a bit misleading and provides rebuttal material for the dissenters.

big fan of the blog, first time commenter.

10:46 PM  
Amardeep said...


It's true that global weather patterns are essentially impossible to predict with any precision.

But it is clear that the carbon emissions in the atmosphere are much, much higher than they've ever been. In the film, Gore makes a pretty compelling case that the current situation is unprecedented -- and he gives is solid geological evidence going back 600,000 years in support of it! Nor do we have reason to doubt that there is a close correlation between the temperature rise over the past 50 years and the saturation of CO2 in the atmosphere.

While I concede the various doomsday scenarios mentioned may or may not come to pass as predicted, I think he makes a pretty good case that something needs to be done, and soon.

11:07 AM  
Roger Williams said...

The Aral Sea catastophe has nothing to do with global warming, and everything to do with disastrous Soviet agricultural policy, which diverted the Aral's headwaters to grow cotton in the desert. Using the Aral Sea disaster as "proof" of global warming requires intellectual dishonesty that should be beyond even a politician like Al Gore.

2:09 AM  

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