SLCPs include black carbon (or soot), methane, ground level (tropospheric) ozone, and hydrofluorocarbons (HFCs) – all have a global warming potential hundreds to thousands times that of carbon dioxide. Black carbon and ozone also seriously impact human and plant health. Agriculture, transport, domestic and commercial refrigeration are the sectors that product the largest emissions of methane, black carbon, particulate matter, and hydrofluorocarbons.
In 2010 an estimated 64,000 people died prematurely in the region from exposure to fine particulate matter (PM2.5) and ground level (tropospheric) ozone. Ozone was also responsible for an estimated 7.4 million tonnes in yield losses of soybean, maize, wheat, and rice. If no action is taken to improve air quality, by 2050 annual premature mortality from PM2.5 and ozone exposure is expected to almost double while annual crop losses could rise to about 9 million tonnes.
The assessment, developed by 90 authors and led by experts from the region, found that poor air quality and climate change affects vulnerable populations and environment in the region resulting in premature deaths, crop yield losses, and ecosystem damage. They propose mitigation strategies tailored to the region and recommend concrete measures aimed to reduce SLCPs.
The potential benefits from implementing these measures, by 2050, include reducing warming in the region by up to 0.9 degrees Celsius; reducing premature deaths from fine particulate matter pollution by at least 26 and ozone by 40%, annually; and avoiding the loss of 3–4 million tonnes of four staple crops – soybeans, maize, wheat, and rice – each year.
Over 45% of methane emissions could be reduced by 2050 through six actions in four sectors: oil and gas production and distribution, waste management, coal mining, and agriculture. These include activities like: the recovery and use of vented gas in oil and gas production, separation and treatment of biodegradable municipal solid waste, and recovering biogas from livestock manure using anaerobic digestion. Black carbon emissions can be reduced by over 80% by 2050 in most countries by focusing on initiatives that modernize cooking and heating stoves, improve diesel vehicle standards to Euro VI equivalent, put diesel particulate filters on vehicles, eliminate high emitting vehicles, and enforce bans on open field agricultural burning. The authors call for stronger public policies and pollution control that can increase the economic incentives in order to maximize the number of benefits for climate action, health, agriculture and sustainable development.
The assessment is published by the United Nations Environment Programme (UN Environment) and the Climate and Clean Air Coalition (CCAC). An accompanying Technical report provides examples of initiatives and measures that have successfully reduced SLCP emissions in region. These include technical and non-technical measures across a range of key sectors, including transport; coal mining and oil and gas production; municipal solid waste and wastewater treatment; livestock rearing and open burning; residential heating and cooking; and small industrial sources.