Global climate change is likely to result in severe droughts and floods in
the world's biggest democracy, with major impacts on human health and food
supplies, according to India's report to the United Nations Framework Convention
on Climate Change. And India is not alone.
An earlier UN report from Namibia predicted "extreme" impacts on water, fish
stocks and agriculture in southern Africa, resulting in economic hardship, food
security problems, social conflict, displacement and increased disease.
By drying up major river basins and altering rainfall patterns, global warming
will significantly affect agriculture and forestry, threatening livelihoods and
food security, says the latest report, released by India's new environment
minister, A Raja.
The report predicts that maximum temperatures will increase by 2°C to 4°C over
the next 50 years, with northern India expected to experience the greatest
increase.
This corresponds with claims made earlier this year by scientists at the Indian
Institute of Tropical Meteorology in Pune, who predicted "phenomenal"
temperature increases.
Rainfall patterns are also set to change. Western and central areas could have
up to 15 more dry days each year, while in contrast, the north and north-east
are predicted to have five to 10 more days of rain annually. In other words, dry
areas will get drier and wet areas wetter.
The report predicts that the area of India prone to malaria will increase by at
least 10 percent by 2080, as changing weather patterns will result in more
potential breeding grounds for malarial mosquitoes at higher altitudes.
Most major river basins across the country are likely to become considerably
drier, resulting in constant - occasionally acute - water shortages, the report
says.
This could shift forest boundaries and affect biodiversity in the regions
affected.
In coastal areas, the key climate-related risks include more frequent tropical
cyclones and rises in sea level that would submerge mangrove forests and
increase the salinity of wetlands.
The report says if sea levels were to rise by one metre, over seven million
people in India could be displaced, and more than 5 000 square kilometres of
land and 4 000km of roads could be lost.
Despite the diversity and extent of threats posed to India by climate change,
the report says Indian emissions of greenhouse gases have been "very low".
Raja says this strengthens India's negotiating position in various climate
change forums.
Speaking at the release of the report, he said India would continue to meet its
development needs but is concerned about the likely impact of severe floods on
its infrastructure such as roads and railways, as well as the likely increase in
electricity needs to pump underground water and cool buildings in hot areas.
Earlier this year, scientists at the Pune-based Indian Institute of Tropical
Meteorology (IITM) used two models to forecast the impact of global warming.
Both models predict that the country's temperatures will rise significantly
until the end of the century. But the two models differ on the effect on monsoon
rains.
One global climate model predicts that temperatures in India are likely to rise
by 2°C to 3°C by the end of the century if greenhouse gas concentrations
increase by one percent each year.
Rupa Kumar Kolli, head of the institute's climatology and hydrometeorology
division, who presented the findings at the Indian Science Congress in
Chandigarh, said the increase could have serious consequences for agricultural
crop growth and weather patterns, given that India's temperature has risen by
only 0,4° to 0,6°C during the course of the past century.
The other model - a high-resolution regional climate model developed under joint
Indo-UK collaboration - also projects a general warming over India.
The IITM team has yet to run the regional model up to the end of the century,
but an analysis up to 2050 indicates a temperature rise of between 1°C and 2°C,
in line with estimates of the global model.
The two models, however, come up with different conclusions about the impact of
global warming on India's monsoon rainfall - the most crucial weather element
that is the lifeline to the country's agriculture and central to the livelihoods
of 70 percent of the country's population.
The global model predicts a 10 percent increase in monsoon rainfall over the
next century.
In contrast the regional model predicts that rainfall will remain at current
levels up to 2050.
Both models indicate a weakening of the link between El nino, the warming of
eastern Pacific waters that affects global weather patterns, and the monsoon.
Kolli says the weaker link has already been evident in India over the past two
decades.
"This is now being considered an early signal of possible global warming effect
on monsoon variability," he says.
Global warming, however, is not expected to affect the link between El nino, or
the cold sea surface temperatures in tropical Pacific waters, and the Indian
monsoon. The institute is also running the regional model against 10 to 15
scenarios based on differing patterns of human behaviour that are likely to lead
to an increase in the use of fossil fuels and concentrations of greenhouse gases
and aerosols.
While greenhouse gases such as oxides of carbon, nitrogen and sulphur increase
atmospheric temperatures by trapping heat, aerosols - tiny atmospheric particles
produced naturally through volcanic eruptions, dust storms and fires, or through
human activities such as fossil fuel burning - cool the air by scattering and
blocking the sun's radiation to the earth.
Large cities in India and China are recording an "alarming" increase in aerosols
due to human activities, creating "hotspots" for climate change, warns A
Jayaraman from the Ahmedabad-based Physical Research Laboratory, which is
studying the likely impact of aerosols on India's climate.
TV Padma writes for the non-profit science news agency for the developing world,
the Science and Development Network, online at www.scidev.net.