Rising sea salinates India's Ganges
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.