According to chief scientists from the Indian Ocean Experiment (INDOEX), a $25 million programme involving 250 researchers from the US, Europe and India, the mixture of soots, sulphates, nitrates, organic particles, fly ash and mineral dust from fossil fuel and biomass combustion, is reducing the light reaching the ocean by 10%, and is cutting light to the subcontinent even further.
According to UNEP Executive Director, Klaus Toepfer, the brown haze could have profound effects on human health, crop yield, and rainfall patterns over Asia. “Looking at the long term warming effect from greenhouse gases and the relatively acute, short-term effects of air pollution, and their interaction at regional levels, it is an important area of further research, particularly if the hydrological cycle and human health are affected,” he said.
According to UNEP staff, who took a plane flight over Kathmandu, the haze extends vertically to at least five kilometres above the ground, two kilometres further than previously measured by the INDOEX programme.
“It is too early to tell how the haze might effect the formation of the monsoon and regional and global climate patterns, but the significance of these initial measurements suggest more knowledge is urgently needed,” said Professor V Ramanathan of the Scripps Institute of Oceanography at the University of California, and one of the research leaders.
The scientists now plan to establish a network of ground-based monitoring stations throughout Asia to study the composition and seasonal pattern of the haze, a programme which the UNEP has pledged to facilitate. In the longer term, the UNEP also intends to co-ordinate policy in order to address the problem. “In the Third Assessment Report we have a compelling picture of the causes and effects of global warming and the urgent need to shift towards a clean energy future,” said Toepfer (see related story).