Asian brown cloud will cause climate crisis unless action is taken, says report

The ‘Asian brown haze’ phenomena, which restricts 10-15% of sunlight hitting the earth’s surface in the region, is the likely explanation for recent disasters such as the Bangladeshi floods and drought in Pakistan, says a United Nations Environment Programme report.

The Asian Brown Cloud: Climate and Other Environmental Impacts, reveals that the detrimental impact on climate is having repercussions on health and agriculture, with India alone estimating 37,000 premature deaths due to air pollution and a 10% reduction in the winter rice yield.

The report attributes “impressive economic development” in the region to the creation of this pollution. “The scope and magnitude of the environmental consequences of the demands [on energy and mobility] are far reaching, especially with respect to air pollution,” says the report.

Last April the UNEP facilitated a programme of ground based monitoring stations throughout Asia, where a team of scientists studied the haze (see related story). This new report identifies sources behind the pollution and advises on the need to reduce activity that is leading to this threat.

“The haze is the result of forest fires, the burning of agriculture wastes, the dramatic increases in the burning of fossil fuels in vehicles,” said Klaus Toepfer, Executive Director of UNEP at the launch of the report in London last week. “More research is needed, but these initial findings clearly indicate that this growing cocktail of soot, particles, aerosols and other pollutants are becoming a major environmental hazard for Asia,” he added.

The report, compiled by the University of California’s Centre for Clouds Chemistry and Climate X, is based on scientist’s observations working on the Indian Ocean Experiment (INDOEX) and incorporates new satellite readings and computer modelling.

The scientists discovered that whilst blocking some solar energy from the earth’s surface, the brown cloud also has heat-absorbing properties that are warming lower parts for the atmosphere in the area. The effect of surface cooling and lower atmosphere heating is a change in the winter monsoon, says the report, resulting in a decrease in rainfall over northwestern Asia with an increase in rain over the eastern coast.

The models used in the study predict a 20-40% reduction in rain over Northwest India, Pakistan and the neighbouring western central Asian region.

Consequences of the brown haze have already been seen in recent times, the report cites droughts and floods in the region as examples. It predicts future repercussions to be:

  • more and smaller raindrops resulting in less rainfall perhaps driving it away from populated regions;
  • less solar energy hitting the earth’s oceans will reduce the evaporation of moisture which controls summer rainfall;
  • decrease agriculture production will result from reduced sunlight;
  • acid rainfall from acid in the haze; and
  • premature deaths from increased respiratory illnesses.

The researchers on the study – Project Asian Brown Cloud – hope to establish observatories to study the haze and are calling for an action plan to address the hazard.

“We stand on the eve of the World Summit on Sustainable Development,” said Toepfer. “The huge pollution problems emerging in Asia encapsulate the threats and challenges the Summit needs to urgently address – achieving economic growth without sacrificing health, and the wealth of the planet. We have the findings and the technology and finance, now let’s develop the science and find the political and moral will to achieve this for the sake of the world,” he concluded.

Story by Sorcha Clifford

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie