Seas may rise 10 yards during centuries ahead

Sea-level rise is currently measured in millimeters per year, but longer-term effects of global warming are going to force our descendants to measure sea-level rise in meters or yards.

Each Celsius degree of global warming is expected to raise sea levels during the centuries ahead by 2.3 meters, or 2.5 yards, according to a study published Monday in Proceedings of the National Academy of Sciences.

The world is currently trying (and failing) to reach an agreement that would limit global warming to 2 degrees Celsius. Business-as-usual practices could yet raise temperatures by 4 (or even more) degrees Celsius.

Multiply 2.5 yards by 4 and you are left with the specter of tides that lap 10 yards higher in the future than today. That’s 30 feet, the height of a three-story building. For comparison, the seas rose less than a foot last century.

Continue reading at Grist …

Electricity crisis, water crisis and more. How Climate Change is changing Pakistan

Climate change is an issue that the common needs to understand. Through radio Desiree Francis attempts to pass on this understanding to her listeners and make them hear what experts say on the issue.

A farmer boy from Badin brings back his family and cattle to a less flooded area.-By Desiree Francis

It is the same old, same old

Despite grand promises and the even grander city beautification projects, one short, heavy burst of rainfall and Colombo city grinds to a halt. This was the case on Monday night when torrential downpours submerged a number of roads in and around Colombo, most of them in the so-called affluent areas, causing massive traffic jams and forcing motorists to seek out alternate routes. A common sight on Monday night was of stalled cars and stranded motorists wading knee deep in water, looking for assistance that wasn’t forthcoming. MORE …

Year 2012 among top ten warmest years: WMO

GENEVA/ISLAMABAD: The World Meteorological Organization’s Statement on the Status of the Global Climate says that 2012 joined the ten previous years as one of the warmest — at ninth place — on record despite the cooling influence of a La Niña episode early in the year, according to a WMO report released last weekend.

The 2012 global land and ocean surface temperature during January–December 2012 is estimated to be 0.45°C (±0.11°C) above the 1961–1990 average of 14.0°C. This is the ninth warmest year since records began in 1850 and the 27th consecutive year that the global land and ocean temperatures were above the 1961–1990 average, according to the statement. The years 2001–2012 were all among the top 13 warmest years on record.

“Although the rate of warming varies from year to year due to natural variability caused by the El Niño cycle, volcanic eruptions and other phenomena, the sustained warming of the lower atmosphere is a worrisome sign,” said WMO Secretary-General Michel Jarraud. “The continued upward trend in atmospheric concentrations of greenhouse gases and the consequent increased radiative forcing of the Earth’s atmosphere confirm that the warming will continue,” he said.

“The record loss of Arctic sea ice in August-September — 18% less than the previous record low of 2007 of 4.17 million km2 — was also a disturbing sign of climate change,” said Mr Jarraud. “The year 2012 saw many other extremes as well, such as droughts and tropical cyclones. Natural climate variability has always resulted in such extremes, but the physical characteristics of extreme weather and climate events are being increasingly shaped by climate change,” he said.

“For example, because global sea levels are now about 20 cm higher than they were in 1880, storms such as Hurricane Sandy are bringing more coastal flooding than they would have otherwise,” said Mr Jarraud.

WMO’s annual statements gather the key climate events of each year. The series stands today as an internationally rec­ognized authoritative source of information about temperatures, precipitation, extreme events, tropical cyclones, and sea ice extent. The newly released statement provided in-depth analysis of regional trends as part of a WMO drive to provide more information at regional and national levels to support adaptation to climate variability and change.

The 2012 climate assessment, the most detailed to date, will inform discussion at WMO’s Executive Council meeting (15-23 May 2013).

Above-average temperatures were observed during 2012 across most of the globe’s land surface areas, most notably North America, southern Europe, western Russia, parts of northern Africa and southern South America. Nonetheless, cooler-than-average conditions were observed across Alaska, parts of northern and eastern Australia, and central Asia.

Precipitation across the globe was slightly above the 1961-1990 long-term average.  There were drier-than-average conditions across much of the central United States, northern Mexico, northeastern Brazil, central Russia, and south-central Australia. Wetter-than-average conditions were present across northern Europe, western Africa, north-central Argentina, western Alaska, and most of northern China.

Snow cover extent in North America during the 2011/2012 winter was below average, resulting in the fourth smallest winter snow cover extent on record, according to data from the Global Snow Laboratory. This was in marked contrast to the previous two winters (2009/2010 and 2010/2011), which had the largest and third largest snow cover extent, respectively, since records began in 1966.

Meanwhile, the Eurasian continent snow cover extent during the winter was above average, resulting in the fourth largest snow cover extent on record. Overall, the northern hemisphere snow cover extent was above average – 590000 km2 above the average of 45.2 million km2 – and was the fourteenth largest snow cover extent on record.

Greenland ice sheet: In early July, Greenland’s surface ice cover melted dramatically, with an estimated 97 per cent of the ice sheet surface having thawed in mid-July. This was the largest melt extent since satellite records began 34 years ago. During the summer it is typical to observe nearly half of the surface of Greenland’s ice sheet melt naturally, particularly across the lower elevations. However, in 2012 a high-pressure system brought warmer-than-average conditions to Greenland, which are associated with the rapid melting.

Arctic sea ice extent reached its record lowest level in its annual cycle on 16 September at 3.41 million km2. This value broke the previous record low set on 18 September 2007 by 18 per cent. It was 49 per cent or nearly 3.3 million km2 below the 1979–2000 average minimum. The difference between the maximum Arctic sea-ice extent on 20 March and the lowest minimum extent on 16 September was 11.83 million km2 – the largest seasonal sea-ice extent loss in the 34-year satellite record.

Antarctic sea-ice extent in March was the fourth largest on record at 5.0 million km2 or 16.0 per cent above the 1979–2000 average. During its growth season, the Antarctic sea-ice extent reached its maximum extent since records began in 1979 on 26 September, at 19.4 million km2. This value surpassed the previous maximum sea-ice extent record of 19.36 million km2 set on 21 September 2006.

Extreme Events: Hurricane Sandy killed close to 100 people and caused major destruction in the Caribbean and tens of billions of US dollars in damage and around 130 deaths in the eastern United States of America. Typhoon Bopha, the deadliest tropical cyclone of the year, hit the Philippines – twice – in December. During the year, the United States and south-eastern Europe experienced extreme drought conditions, while West Africa was severely hit by extreme flooding. The populations of Europe, northern Africa and Asia were acutely affected by extreme cold and snow conditions. Severe flooding occurred in Pakistan or a third consecutive year.

Climate change is aggravating naturally occurring climate variability and has become a source of uncertainty for climate-sensitive economic sectors like agriculture and energy.

“It is vital that we continue to invest in the observations and research that will improve our knowledge about climate variability and climate change,” said Mr Jarraud.

“We need to understand how much of the extra heat captured by greenhouse gases is being stored in the oceans and the consequences this brings in terms of ocean acidification and other impacts. We need to know more about the temporary cooling effects of pollution and other aerosols emitted into the atmosphere. We also need a better understanding of the changing behaviour of extreme weather and climate events as a consequence of global warming, as well as the need to assist countries in the most affected areas to better manage climate-related risks with improved climate early warning and climate watch systems,” said Mr Jarraud.

The Global Framework for Climate Services (GFCS), adopted by the Extraordinary World Meteorological Congress in 2012, now provides the necessary global platform to inform decision-making for climate adaptation through enhanced climate information.

The story published first in Lahore Times on May 6, 2013


Will the climate ever change for Sundarbans?

Published online 30 April 2013 in Nature India

Seven years after the first report on the ‘vanishing islands‘ of Sundarbans, Subhra Priyadarshini revisits the fragile delta in the Bay of Bengal to find that it is not just climate change that threatens the existence of this world heritage mangrove tiger-land spread across the Indo-Bangladesh border.

(Pictures: Subhra Priyadarshini)

The seas are rising around the Sundarbans. That is old news.

Two islands in this 100-odd island conglomerate have vanished from the face of earth. Even that is old news, met with a stoic shake of the head by environment refugees who now inhabit Sagar, the biggest island in west Sundarbans. For them ‘climate change’ is just another phrase that NGOs and people from the media use to describe everything that is wrong with their lives.

In their life full of challenges, the loudest alarm bells ring almost before each monsoon — of the fury that the sea unleashes between September and November. Severe cyclones — four of which have visited the Sundarbans between 2007 and 2009 — are gulping in more and more land every year. The world’s only mangrove tiger-land is now a constantly shrinking landmass, its existence threatened by severe cyclonic storms, unmanageable demographics, rising seas, coastal flooding and erosion.

Though just a bit of this fear is reflected in government figures, it is clearly evident in Shamila’s voice. “The fury of the sea now is like never before,” she says standing right where she stood seven years back outside her hut in one of the many refugee colonies dotting Sagar. Shamila has grown from a shy teenager into a confident mother of two and knows where to flee if the going gets tough. “We will go to Kolkata and do something there,” she says talking of her secret dream to settle in the burgeoning megapolis, capital of West Bengal, where “you get beautiful saris”.

Climate displacements

Shamila’s father Sheikh Abdullah did something similar in the late 1990s when he left the sinking island of Lohachara in the vicinity, along with 7000 other refugees from various islands, and sought shelter in Sagar. Lohachara does not exist on the map anymore along with another island Bedford, which never had any human habitation.

Scientists estimate that Sagar will be the worst hit in future with over 30,000 people displaced by 2020 even as neighbouring Namkhana produces 15,000 more refugees. The other islands, all in the western end of the estuarine delta, predicted to face similar fates are Ajmalmari (east and west), Dalhousie, Dakshin Surendra Nagar, Moushuni, Lothian, Ghoramara, Dulibhasani, Dhanchi, Bulchery, Bhangaduani and Jambudwip.

According to estimates, between 2001 and 2010, the net loss of land to the seas across the Indian Sundarbans stands at 63 square kilometre. About 1.35 million people are currently at high risk from sea level rise, storm surges and coastal flooding with a further 2.4 million people exposed to moderate risk.

Sugata Hazra, Director of the School of Oceanographic Studies at Jadavpur University in Kolkata has been studying the seas and listening to the problems of these refugees for long years now. “There have been four cyclones — Sidr, Nargis, Bijli and Aila — in the northern part of the Bay of Bengal in the last part of the decade. Though the frequency of these storms and cyclones has gone down, the intensity appears to be increasing, possibly as a result of rising sea surface temperatures,” he says. Hazra predicts that the 2015 pre-monsoon is going to see another bout of massive flooding.

The pattern appears to be “in line with global climate models which also predict declines in cyclone frequency”, Hazra says. Other scientists studying the trends in the Bay of Bengal say the region has registered 26 per cent increase in severe cyclonic storms in the last 120 years, intensifying post-monsoon.1

However, quick flooding is by far the biggest threat. Slow sinking of islands, on the other hand, takes centuries to get noticed, Hazra says.

The Rising seas

Hazra has been harping on the sea level rise issue for long too, though not many acknowledge this as an immediate threat preferring to call it ‘part of a slow global phenomenon’. “The threat of severe coastal erosion due to relative sea level rise is something that needs immediate attention,” Hazra insists. He quotes an analysis of 50 years of data from three data stations in the Hugli estuary that show a sea level increase of between +0.76mm/year and +5.22 mm/year at different locations in the Indian Sundarbans.2

His own estimation of tide gauge data from the Sagar island observatory between 2002 and 2009 shows a relative mean sea level rise at the rate of 12 mm/year. “In the last 25 years, the rate of relative sea level rise comes close to 8 mm/year, significantly higher than the rate of 3.14mm/year in the previous decade,” he says.

In a recent report he co-authored for the World Wide Fund for Nature (WWF)3, Hazra says besides global warming and the subsequent thermal expansion of water, the rather rapid subsidence of the Bengal delta (2-4 mm/year), compaction of silt and other local causes may be responsible for the exceptionally high rate of relative sea level rise in the Indian Sundarbans.

For the locals, these small numbers do not make a difference. “I don’t know if the sea level is rising. I can see the sea rise during high tide and ebb during low tide,” says Gokul Ghorai, who lives in one of the picturesque islands and sustains his family of five through fishing. “All I know is that the sea keeps pushing our embankements back every couple of years all over these islands.” In 2009 alone, the Aila cyclone demolished about 1000 km of embankments across Sundarbans. “Around 50,000 people left the islands to become labourers in places places like Mumbai and Delhi — there’s no official documentation on how many left,” Hazra says.

Hazra also estimates that the temperature in the Sundarbans will rise by 1°C by 2050 and might have a bearing on the chemical composition of sea water in terms of “increased acidification and decreased dissolved oxygen levels.”

Kumud Ranjan Naskar, a former national fellow of the Indian Council of Agricultural Research (ICAR) and author of several compilations on Sundarbans, feels that the immediate issue at hand is to predict the severe weather events correctly and base the development roadmap of Sundarbans surrounding these events.

“That is much more immediate than climate change, global warming or rising seas,” he says. Naskar, who retired from ICAR a couple of years back and now lives with two 50-feet high Sundari trees in the backyard of his home in suburban Baruipur, not far from the delta, also suspects the theory of subsidence of the Sundarbans. “There is a lot of complex estuarine arithmetic here – to prove subsidence is not so easy.”

The dwindling forests

The Sundarban delta, formed by the river trio Ganga, Brahmaputra and Meghna, also faces a major threat from discharges of untreated domestic and industrial effluents carried by tributary rivers. A major oild disembarkment terminal in eastern India – the Haldia Port Complex – has been a source of contaminated mud from harbour dredging.

Multiple studies456 over the years have found that chemical pollutants such as heavy metals, organochlorine pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons from agricultural runoffs, wastewater, sewage discharges and agricultural wastes might be changing the estuary’s geochemistry irreversibly and affecting the local coastal environment.

Naskar says it does not augur well for the mangrove plant species Sundarbans is so famous for. Of the 69 species found in India, 63 exist in the estuarine delta and his estimate is that the delta may hold up to 140 mangrove, mangrove associates, back mangrove and coastal zone flora. Naskar, who spearheaded the creation of a natural genepool project in one of the islands some years back, is not so optimistic about the forest cover anymore. “The idea was to preserve one specimen of every mangrove species found across the Sundarbans for posterity,” he says.

Though the genepool might live on, the natural mangrove vegetation and the overall land area has been steadily decreasing.

Hazra fishes out satellite maps from his cluttered desk to show comparative images that establish a 5 percent loss of forest cover in the 20 years between 1989 and 2009.

Across the Sundarbans, degraded forests are being replaced by saline blanks, further reducing forest cover. “Climate induced increase in surface-ocean stratification has effects on phytoplankton productivity which may lead to an overall decrease in primary production,” Hazra notes.

On a visit to the islands his keen eye catches new creeks. “Look at the number of streams inside these forests. There are so many more now — the density of the streams is also increasing.”

Warming up to climate change

The West Bengal government, which till recently did not publicly acknowledge the climate change threat to Sundarbans, has made a clear departure in its stand in the last couple of years. A three-year long exercise that culminated in creation of a State Action Plan on Climate Change7, made public last month (March 2013), now underlines the major threat that climate change poses in the delta.

“The ground level workers always knew it. Now the policy makers have also quantified the vulnerability posed to the islands due to climate change,” says Debal Ray, Principal secretary of the state’s environment department and a member secretary of the West Bengal Biodiversity Board.

Ray says the government has initiated a number of scientific studies to understand and predict the influence of climate processes in the estuarine delta and is focussing its effort to “prepare for the inevitable”. “The idea is to create better linkages by constructing bridges for evacuation in times of emergency, to create better mobile phone penetration in the islands for early warning dissemination and to automate weather forecast,” he says.

Damning demographics, food fears

72-year-old fisherman Tapan Debnath, who knows the creeks and forests of Sundarbans like the back of his palm, says he went fishing across the islands and rarely saw large habitations when he was a teenager. “I see people everywhere now, in newer patches of land that were earlier forests,” he says.

The islands have an interesting mix of inhabitants — first generation immigrants from East Midnapore district in West Bengal and parts of what is now Bangladesh, descendants of settlers from the days of colonial administration and a small group of tribal people from Chotanagpur plateau brought to clear forests. In effect, Sundarban now has a very high population density.

According to the WWF report, there is a significant increase in the settlement area from 1226 square km to 1666 square km. Available agricultural land has also reduced and the population crossed the 45,00,000 mark in the 2011 census. The mathematics is simple then — it means an increasing threat to land and food security.

The West Bengal government has taken baby steps in trying to introduce salt-resistant varieties of paddy by providing subsidies to farmers. “Since these varieties have lesser productivity than higher yielding ones, we encourage the farmers to cultivate them on a small patch of land and offer them some incentives. This is one of the top priority things we are doing in the Sundarbans today — to conserve salinity tolerant seed varieties in the face of incessant flooding in the region,” Debal Ray says.

The National Bureau of Plant Genetic Resources hunted for the six locally recalled salt-tolerant farmers’ paddy varieties, but found only two — Hamilton and Matla. The others might have been lost from the region after the “green revolution”, the bureau says, and recommends re-introduction of these salt-resistant paddy varieties in the region to ‘enhance adaptive capacity of the farmers against recurrent salt water inundation’.

Ray says the government will need an outlay of Rs 20, 000 crore in India’s 13th Five year plan period to implement all the well-meaning adaptation and mitigation strategies they have set out in the state action plan. “We can only be optimistic that we get this kind of fund to do what needs to be done to protect the Sundarbans,” he says.

  • References

    1. Singh, O. P. Long-term trends in the frequency of severe cyclones of Bay of Bengal: Observations and simulations. Mausam. 58, 59-66 (2007)
    2. Nandy, S. et al. Trend of sea level change in the Hugli estuary, West Bengal. 21st Conference of Indian Institute of Geomorphology. (2008)
    3. Indian Sundarbans delta. A vision. WWF policy document (2011)
    4. Sarkar, S. K. et al. Water quality management in the lower stretch of the river Ganges, east coast of India: An approach through environmental education. J. Cleaner Production 15, 1459-1467 (2007)
    5. Guzzella, L. et al. Distribution of HCH, DDT, HCB and PAH in the sediments of coastal environments of West Bengal, Northeastern part of India. Environ. Int. 31, 523-534 (2005)
    6. Binelli, A. et al. Concentration of polybrominated diphenyl ethers (PBDEs) in Sundarban mangrove wetland, north eastern part of Bay of Bengal (India).Mar. Pollut. Bull. 54, 1220-1229 (2007)
    7. State Action Plan on Climate Change, West Bengal (2013)

Five years after cyclone Sidr

Cyclone Sidr still remains fresh in people’s memory after five years it stuck. Some 4500 people died that fatal night. The victims still remember the destruction as clear as daylight. It is perhaps that burning memory that sends them scampering to the shelters now whenever there is a warning at the coastal areas. And those signals have become more frequent. Sharankhola is a small union of the southern Khulna division where 150 government and non-government organisations have been at work over the last five years. But the coastal people still lag far behind in terms of healthcare, education and food security.