World Health Organisation study lists four key climate pollutants

Clamping down on four key climate pollutants -- black carbon, ozone, methane, carbon dioxide -- can help save an average of 2.4 million premature deaths annually by 2030, says a new report by World Health Organisation. The combined effect of these four pollutants on air pollution contributes to over seven million premature deaths at present.

These four short-lived climate pollutants (SLCPs) not only produce a strong global warming effect, but also impact food security and nutrition, says the report. Reducing global health risks through mitigation of short-lived climate pollutants, brought out by WHO in collaboration with the Climate and Clean Air Coalition.

“Ozone and black carbon in the atmosphere can both negatively influence plant growth and agricultural productivity,” it says, citing a study that found that the combined effects of climate and air pollution reduced India’s wheat yield by as much as 36 per cent in 2010, with the majority of the reductions attributable to the direct effects of SLCPs .

"Quick action to reduce black carbon, methane and other ozone precursors are much needed now," Helena Molin Valdés, head of the UNEP-hosted CCAC, said in a statement, adding that “the sooner we start reducing these pollutants the sooner we will relieve the pressures on climate and human health.”

The report noted that in countries such as India, Nepal and Nigeria, where recent economic growth and demand for electricity have not been matched by power supply, stand-alone diesel generators were a growing source of black carbon emissions, especially in areas that are off-grid or have unreliable access to grid electricity.

The large number of kilns are another source of air pollution in India and China -- the two top producers of bricks. “India alone has an estimated 100,000 kilns that employ around 10 million people,” says the report, adding that bricks are often fired in traditional kilns that release high levels of heath-relevant pollutants, as the fuel used is either wood or coal.

Vehicular pollution is another top pollutant that damages the ozone, with diesel vehicles generally emitting more per km travelled than comparable gasoline vehicles, says the report, seeking a shift to cleaner transport modes.

Ahead of the launch of WHO’s first climate change and health country profiles, to be released before the 2015 Paris Climate Conference (COP21) begins, the report calls upon governments to urgently reduce these pollutants. It suggests four interventions – reduction in vehicle emissions by implementing higher emissions and efficiency standards, policies and investments to prioritise dedicated rapid transit, such as buses and trains and foster safe pedestrian and cycle networks, provide cleaner and more efficient stove and fuel alternatives to low-income households and encourage high and middle-income populations to increase their consumption of nutritious plant-based foods.

“The health benefits that may be obtained from these strategies are far larger than previously understood, and they can be enjoyed immediately and locally,” says Maria Neira, WHO Director, Department of Public Health, Environmental and Social Determinants of Health.