Cutting smog and soot could have fast and broad benefits – UN backed report

Fast and relatively short-term action to curb soot and smog could improve human health, generate higher crop yields, reduce climate change and slow the melting of the Arctic, according to a United Nations-backed study released today.

The study, compiled by an international team of more than 50 researchers and coordinated by the UN Environment Programme (UNEP) and the World Meteorological Organization (WMO), “complements urgent action needed to cut carbon dioxide emissions,” the two agencies said.

Achim Steiner, UNEP Executive Director, said: “The experts spotlight how a small number of emission reduction measures – targeting, for example, recovery of methane in the coal, oil and gas sectors through to the provision of cleaner burning cook stoves; particle traps for diesel vehicles and the banning of open burning of agricultural wastes – offer dramatic public health, agricultural, economic and environmental benefits.”

The report specifically recommends reductions in emissions of methane and black carbon. Black carbons are a major

component of soot and are formed from the incomplete combustion of fossil fuels wood and biomass, including emissions

from cars and trucks, cook-stoves, forest fires and some industrial facilities.

Methane contributes to the formation of ground-level ozone, a major component of urban smog, and a powerful greenhouse gas and air pollutant harmful to human health and ecosystems.

“Big cuts in emissions of black carbon will improve respiratory health; reduce hospital admissions and days lost at work due to sickness… Close to 2.5 million premature deaths from outdoor air pollution could on average be avoided annually

worldwide by 2030 with many of those lives saved being in Asia, it is estimated,” UNEP and WMO said in a joint press

release.
Fast action might also reduce losses of mountain glaciers while reducing projected warming in the Arctic over the coming decades by two thirds.

Big cuts in ground-level ozone could also contribute to reduced crop damage equal to between 1-4 per cent of the annual global maize, rice, soy bean and wheat production.

The report concludes that cutting these so-called “short-lived climate forcers” can have immediate climate, health and

agricultural benefits. This is because, unlike carbon dioxide, which can remain in the atmosphere for centuries, black carbon only persists for weeks.

But the researchers also said that while fast action on black carbon and ground-level ozone could play a key role in limiting near-term climate, “immediate and sustained action to cut back CO2 is crucial if temperature rises are to be limited over the long term.”

The findings were released today in Bonn, Germany, during a meeting of the UN Framework Convention on Climate

Change (UNFCCC).