Climate change mitigation policies can do more than just avert the potential long-term catastrophic consequences that will affect the entire world. Climate policies can also have short-term benefits in the area of human health and agriculture. These benefits were outlined in a recent article in the journal Science, by a group of scientists from around the world. The research article highlighted the potential for mitigating near-term climate change effects, while simultaneously improving human health and agricultural yields.
The research focused on two primary pollutants, methane (CH4) and black carbon (BC), which contribute to climate change and have severe human health effects. The reason for the analysis of these two pollutants is due to their potency and short-lived nature in the atmosphere. When discussing climate change, pollutants are assigned a value which describes its global warming potential (GWP) compared to the standard value, which is Carbon Dioxide (CO2). The GWP compares the amount of heat trapped by a certain mass of the gas to the amount of heat trapped by a similar mass of CO2. The GWP is calculated over a certain time interval, typically 20, 100 or 500 years. This is important to understand because CH4 has a GWP of 25 and BC 55, meaning they are 25 and 55 times more potent than CO2 respectively.
Black carbon is a product of burning fossil fuels or biomass such as wood, and can exacerbate a number of existing respiratory and cardiovascular diseases. The small particles of BC also absorb radiation from the sun causing the atmosphere to warm and alter the patterns of rainfall. Additionally, BC darkens ice and snow, reducing their reflectivity, thus enhancing the warming of the globe. Methane is a colorless and extremely flammable gas, and, as indicated above, has a very high GWP value, making it very a potent greenhouse gas (GHG). CH4 also plays a role in the formation of ground-level ozone, which has serious effects on both human and plant health.
The international research team evaluated approximately 400 control measures based on technologies assessed by the International Institute for Applied Systems Analysis in Laxenburg, Austria. The climate change study focused on 14 measures that had the greatest potential climate benefit. Each of the 14 strategies for reducing BC and CH4 would curb their releases and have significant health benefits. The strategies considered by the researchers for reducing CH4 included capturing gas escaping from coal mines and oil and natural gas facilities, reducing leakage from long-distance pipelines, preventing emissions from city landfills, updating wastewater treatment plants, increasing the aeration in rice paddies, and limiting emissions from manure on cattle or other livestock farms. The strategies analyzed for BC reductions included installing filters in diesel vehicles, restricting high-emitting vehicles from being on the road, upgrading cooking stoves and boilers to cleaner burning types, installing more energy efficient kilns for brick production, upgrading coke ovens and banning agricultural burning.
The results of the study showed a potential for reducing the number of premature deaths by approximately 700,000 and 4.7 million, which are the result of poor outdoor air quality. Additionally, strategies that reduced the BC and CH4 showed the opportunity to increase crop yields by 135 million metric tons per year. Reductions in both pollutants contribute to better crop health. Lastly, by reducing the emissions of these two pollutants, the mean warming potential of the globe could be reduced by 0.5ºC (0.9º F). The researchers concluded that implementing simple measures such as pollution control devices and regulating diesel trucks could prove to have significant health and environmental benefits.