We are facing catastrophic sea-level rise this century on our current greenhouse gas emissions path.
The direct impact of such sea-level rise is so enormous—and so easy to show visually—that other serious ramifications hardly get mentioned at all. So kudos to Reuters for reporting:
KOLKATA, India: Rising sea levels are causing salt water to flow into India’s biggest river, threatening its ecosystem and turning vast farmlands barren in the country’s east, a climate change expert warned Monday.
Much of the world’s cropland—especially in the developing world—is close to sea level and near the shore. I haven’t seen a global quantification of the impact of salt water infiltration. I did find a 2008 discussion of “Global Warming and Salt Water Intrusion: Bangladesh Perspective,” [PDF] which concludes:
Global Warming has already started to hit the Bangladesh coastal areas. The salty sea water intrusion and its disastrous effects in landscape, ecology and human health already created widescale agony amongst the inhabitants of Bangladesh coastal belts ...
A 3-foot rise by century’s end ... would wreak havoc in Bangladesh on an apocalyptic, Atlantis-like scale, according to scientific projections and models.
A quarter of the country would be submerged ... As many as 30 million people would become refugees in their own land, many of them subsistence farmers with nothing to subsist on any longer.
And again, we’re facing five feet of sea-level rise by 2100.
The impact on India of just the salt water infiltration will be devastating, as the Reuters piece details:
A study by an east Indian university in the city of Kolkata revealed surprising growth of mangroves on the Ganges river [photo above], said Pranabes Sanyal, the eastern India representative of the National Coastal Zone Management Authority (NCZMA).
“This phenomenon is called extension of salt wedge and it will salinate the groundwater of Kolkata and turn agricultural lands barren in adjoining rural belts,” said Sanyal, an expert in global warming.
Sea levels in some parts of the Bay of Bengal were rising at 3.14 mm annually against a global average of 2 mm, threatening the low-lying areas of eastern India.
Actually the global average is over 3 mm a year. If we don’t act soon, by century’s end it will be roughly 10 times faster! And now compound that by the loss of the inland glaciers that feed the rivers for hundreds of millions of Indians (see here). And compound that by the extended droughts and desertification that will hit hundreds of millions of Indians (see here). Who can imagine what life would be like in such circumstances?
Climate experts warned last year that as temperatures rise, the Indian subcontinent—home to about one-sixth of humanity—will be badly hit with more frequent and more severe natural disasters such as floods and storms and more disease and hunger.
Sanyal and the department of Oceanography at the Kolkata-based Jadavpur University spotted the mangrove plants, a rare phenomenon along the Ganges river belt, where east India’s biggest city of Kolkata with 12 million people lies.
“We were surprised over the natural regeneration of mangroves along the river bank in Kolkata and it is worrisome,” said Sanyal, who teaches in the university.
Mangroves are more typically found 100 km (60 miles) away in the swampy Sundarban archipelago spread over a 26,000 sq km (10,000 sq mile) area on the world’s largest delta region.
I hope this study gets good coverage in India—a country that will suffer more than most from climate change and that will need to embrace serious climate action in the not too distant future.
This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.
Feed the world sustainably by 2050? Yes, we can!
The Copenhagen Conference on food security
Comments
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Billhook Posted 8:03 pm
05 Feb 2009
As reported here : http://www.livescience.com/environment/090205-more-sea-level-rise.html
The time scale of such a recovery project implies that we probably cannot avoid the loss of much of the best of the world's farmland, plus our coastal cities and docks.
The foreseeable consequent disruption of our capacity to trade, manufacture and organize complex operations implies that we now face a declining window of opportunity for getting that recovery program under way.
The very possibility of doing so rests, of course, on achieving a Treaty of the Atmospheric Commons rather then sliding into mere "devil take the hindermost" confusion & strife.
Regards,
Billhook
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Russ Posted 11:44 pm
05 Feb 2009
(It'll probably be reposted here in a day or so.)
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Billhook Posted 11:48 pm
05 Feb 2009
thanks for the info - I'll have a look.
Regards,
Billhook
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amazingdrx Posted 12:10 am
06 Feb 2009
Algae grows in salt water, that's the key.
I guess Dean Kamen needs to work on this next, after his water invention.
Brewers yeast, that can grow on algae provides all the amino acids. So there you have it, the future of humanity given unplanned reproduction and a lack of reproductive rights for women.
A life of "green goo" as opposed to the nano-tech apocalypse of "gray goo". The ultimate quantity over quality of life trend.
http://amazngdrx.blogharbor.com/blog John Schneider, Northern Wisconsin
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thoughtfulman Posted 2:41 am
06 Feb 2009
If the average rate of sea level rise over the last 20,000 years continues, at 4.6 mm per year, by 2100 the level will be up 419 mm or about 16" naturally. This rate will likely continue until the onset of the global temperature decline preceeding the next ice ige.
Incidentally, salt water intrusion under seaside land, displacing fresh groundwater, is common. It is caused by excessive withdrawal of the groundwater, which both lowers the overlying land and also creates low pressure areas which causes the sea water to migrate underground to that area.
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Billhook Posted 7:36 am
06 Feb 2009
A rather brief survey of the literature will confirm this for you.
Your conclusion, that our pollution thus cannot be causing the current acceleration of SLR reflects a different but equally elementary error, which I would hope the average high school science teacher could explain for you.
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Joe - I wish you could say when we're likely to see an integrated forecast of SLR within present adults' lifetimes, that is, by say 2050.
By integrated I mean one that includes thermal expansion plus sundry glaciers' melt plus Greenland Ice Cap melt (as the Arctic Ice Cap is lost) plus WAIS melt plus the latter's consequences.
In total these could eventually yield perhaps 17 metres SLR under BAU (roughly 56 feet). But there needs to be a credible assessment of the likely all-sources rise by mid-century under both BAU and war-footing mitigation [WFM}, if this threat is going to properly assist the climate-treaty's negotiation.
Is there someone you could nudge ?
Regards,
Billhook
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