Feeling The Global Heat

THE pulse of the eastern Pacific, measured by sophisticated instruments on floating buoys, is climate's new shaman. Its slingshot nemesis across the globe. This week, representatives from 160 countries around the globe are meeting in Kyoto, Japan, to try to wrestle down in coming years the ominous down blanket of carbon dioxide that envelops the planet. The shaman (El Nino), for some, is just an ugly contraction of the biceps of this blanket of planet-warming gas. Outlook looks at things 50 years hence: how a rise in global temperature will affect the Indian subcontinent. Though there is no comprehensive study yet, a few individuals have sketched some observations. And they are worrisome.

Wheat and Rice suffer

A study conducted by Dr Murari Lal of the Centre of Atmospheric Sciences, IIT, Delhi, and the Indian meteorological department examined the vulnerability to climate change of wheat and rice crops in northwest India by the middle of the next century. Says Lal: "While wheat crops are found to be sensitive to increases in maximum temperature, rice crops are vulnerable to increases in minimum temperature." The researchers found that though there might be some higher yields because of the doubling of CO2, a two-to-three degree rise in temperature nearly cancelled the positive effects of the CO2 increase. In fact,under some conditions, their computer model showed a fall in rice output of nearly 20 per cent. Concludes Lal: "Acute water shortage conditions combined with thermal stress should adversely affect both the rice and wheat crops in northwest India even under the positive effects of enhanced CO2." Rice production accounts for 50 per cent of all cereal produced in India.

Says Jyoti Parikh, acting director of the Mumbai-based Indira Gandhi Institute of Development Research: "In a study conducted by us, we found that yield losses for rice and wheat crops could be in the range of 15-30 per cent and 30-50 per cent depending upon the severity of climate change. The associated losses in GDP would be between 1.8 to 3.5 per cent."

 Particularly vulnerable would be low-income populations that depend on isolated agricultural systems. Two other factors increasing vulnerability are floods and the fact that a significant portion of agriculture is rain-fed. In India, the crop area affected by floods is nearly one-third of the average flood-prone area. And in eastern India approximately 80 per cent of the 20 million hectares (ha) of rice is grown in rain-fed lowlands. It has been estimated that per ha rice yields will need to be doubled by AD 2025 to meet demand. That will pressurise rice yield from irrigated areas to rise to 8 tonnes per ha compared to current yields of 4.9 tonnes per ha.

The findings are alarming, given the fact that India's current annual increase in foodgrains is 1.7 per cent while its population growth is 1.9 per cent. Just to keep up with population demands India will need an annual grain production increase of 4 per cent. To compound the woes, the Americans have started pressurising India to buy their wheat surplus. If the country succumbs, it could raise serious questions about food security.

Monsoons fail

About 60 per cent of the gross cropped area in India corresponds to the southwest monsoon (June-September) season, indicating its heavy dependence on the monsoon rainfall. While most of the numeric models trying to predict future climate changes take into account just enhanced CO2, and predict an increase in rainfall(see chart below), a model developed by Dr Lal in collaboration with a scientist from Europe's Max Planck Institute also takes into account the highly-polluting sulphate aerosols. Sulphate aerosol compounds have increased dramatically in the earth's atmosphere since the 1950s. Says Lal: "The results showed an increase in annual mean surface temperature of 1°C over the land regions of the subcontinent in the 2040s." With land warming to be lower in magnitude than the adjacent ocean, it would also lead to a decline in the land-sea thermal contrast, the primary factor responsible for monsoons. Conclusion: the model predicts a decline in monsoon rainfall. Adds Lal: "Our model showed a 6 cm decrease in rainfall in India by the middle of the next century over the current 85 cm annual rainfall. That's a 0.5 mm per day decrease."

Malaria, dengue and cholera on the rise

In the forthcoming Intergovernmental Panel of Climate Change (IPCC) special report on the 'regional impacts of climate change', the authors list some vector-borne diseases in tropical Asia that are expected to increase as a result of global warming. According to the report: "Increases in epidemic potential of 12-27 per cent for malaria and 31-47 per cent for dengue are anticipated. Waterborne and water-related infectious diseases account for about 70 per cent of the epidemic emergencies in India." In 1995, for instance, in eight countries of the region—Bangladesh, Bhutan, India, Indonesia, Myanmar, Nepal, Sri Lanka and Thailand—WHO estimated the total death toll from diarrhoea as 1.03 million. India alone accounted for 71 per cent of these deaths. 

Alarmingly, salinities between 5 ppm (particles per million) and 30 ppm, which were detected in the inland coastal areas of Bangladesh, as well as in sea water in higher concentrations, are very favourable for the growth of the cholera virus. In the Bay of Bengal, a direct correlation has been found between cholera cases and a rise in ocean temperature. Two peak periods of cholera outbreak have been identified: from early April to mid-May and from early September to the end of November.

Besides, the economic impact of treating drug-resistant malaria in the region is equally daunting. A study estimated that in rural Bangladesh a complete course of treatment may cost one month's wages ($40) for an agricultural worker. And the dengue epidemic in Delhi last year may just have been a precursor of worse things to come.

The fragile Sunderbans

The special report also details the possible impact on mangrove systems, of which the Sunderbans are a part. Sea level rise poses a distinct threat to this ecosystem. The largest continuous mangrove in the world faces a direct threat to fish species. If the saline water front moves further inland, Heritiera fomes (the dominant species in the landward freshwater zone) comes under threat. Species like Excoecaria agallocha in the moderate saltwater zone and Ceriops decandra could also suffer. Five to six lakh people are estimated to be directly employed in the Sunderbans for at least half the year. In addition, many industries dependent on the Sunderbans for raw material could be seriously hit.

Global warming would also result in changes in high-elevation ecosystems. For instance, a kind of flora colonisation, as the distribution of species shifts to higher elevations. High elevation tree species—such as Abies, Acer, and Betula—which prevail in the Greater Himalayas because of their adaptation to cold temperatures would have to compete with new arrivals.

Teakwood decline

In a study conducted in 1996 by two scientists, A.N. Achanta and R. Kanetkar, on the impact of climate change on forestry productivity in Kerala, it was found that a projected decrease of soil moisture would cause teak productivity to decline from 5.40 m

3/ha to 5.07 m3/ha. The productivity of deciduous forests would also decline from 1.8 m3/ha to 1.5 m3/ha.

Receding glaciers

A rapid reduction in the size of Himalayan glaciers was indicated in a study undertaken by Professor Syed Iqbal Husnain of the Jawaharlal Nehru University's School of Environment Sciences. The 25-km long Gangotri glacier, for instance, has been receding 200 metres a year for the last five years. Before that, the rate of recession was 18 metres a year. Compare this with a total reduction of 731 metres in the entire 19th century.

Moreover, we could be using up our snow faster than we think. A study of one large catchment (the Chenab) in the western Himalayas showed that the average snowmelt and glacier-melt contribution to the annual flow was 49.1 per cent—a significant portion of runoff derived from snow in the dry season, when water demand is at its peak. Dry season flow in the major Himalayan rivers in a given year results directly from the previous year's monsoon. Catchments in Nepal, for instance, supply about 70 per cent of the dry season flow of the river Ganges. Rising temperature is also bringing about an increase in the number of glacial lakes, which in turn spawns the threat of glacial lake outburst floods (GLOFs). Two GLOFs occurred in the Lunana area of Bhutan in October 1994 and in Khumbu Himal, Nepal, in 1985.

Seven million people will be displaced

In a 1995 paper, scientist R.J. Nicholls estimated that a 1 metre rise in sea level would displace seven million people in India and 15 million in Bangladesh, assuming there is no adaptation and no change in existing population. Land loss in Bangladesh and India alone would be 36,000 sq km. Says Anil Agarwal, director of the Centre of Science and Environment: "It's only the blind who will say that such calamitous impact of climate on a neighbour like Bangladesh won't affect India." Another study conducted by Prof. V. Asthana of JNU's School of Environmental Sciences estimates the total number of households affected by a sea level rise of 1 metre at 7.5 lakh. Says he: "The most vulnerable areas would be the east coast deltas, the Kerala coast and Lakshadweep."

 The disparity: Carbon emissions are the most prominent source of global warming. At Kyoto, 160 nations will be negotiating a legal instrument for the reduction of emissions. The per capita emission of the US is 5 tonnes of carbon per year. The world per capita average is 1.1 tonnes per year. On the other hand, India's per capita emission is just 0.25 tonnes per year. In rural areas, it's as low as 54 kg per person. And for India, carbon emissions from the energy system are even more important since coal is the primary source of energy. Says Prof. P.R. Shukla of the Indian Institute of Management, Ahmedabad, who's currently working in this field: "A direct impact of carbon emission limitations is on energy prices. The production costs of energy-intensive commodities will rise significantly—particularly, cement, steel, brick and aluminium." Shukla concludes that the loss of competitiveness shall be greater for Indian industries compared to industries in nations less dependent on coal.

India, therefore, faces a perplexing situation. It needs energy for minimum development but, if at Kyoto the developing economies are unable to negotiate a legal instrument that takes into account their needs—under pressure from the developed economies, notably, the US, Canada, Australia, Japan and others—a new legalised system of global colonialism might well be put in place. Says R.K. Pachauri, director of the Tata Energy Research Institute in New Delhi: "We have to categorically reject all pressure to put targets for emissions on our economies. Let those who did the damage bear the brunt of the pain."

That, however, might be too ideal a scenario. For India, it's going to be a double whammy. The country will have to pay for the past sins of developed economies and also suffer a neo-colonialism that might ensure it doesn't progress beyond a point.