On May 12, 2009 Wilson Center on the Hill and the China Environment Forum cohosted a session on the potential of U.S.-China cooperation on environment and health. Speakers included Denise Mauzerall, associate professor at Woodrow Wilson School at Princeton University, Robert O'Keefe, vice-president at the Health Effects Institute (HEI), and Durwood Zaelke, president of the Institute for Governance and Sustainable Development. The session was moderated by Jennifer Turner, director at China Environment Forum at the Woodrow Wilson Center.
Mauzerall opened the discussion by noting the connections between air pollution and climate change, and their respective impacts on health. Some air pollutants increase radiative forcing. "Radiative forcing"is the amount of energy that is trapped in the atmosphere by greenhouse gases or aerosols, thereby warming the climate. (By analogy, radiative forcing is similar to the heat that a body releases when cold – heat that causes the temperature to rise if trapped or caught in a blanket.) Examples of pollutants that increase radiative forcing are ozone and black carbon. Other air pollutants such as sulfates, and organic and carbon aerosols decrease radiative forcing, thereby causing a cooling effect in the atmosphere.
Sulfur dioxide (SO2) affects climate in a different manner. Reducing SO2 emissions is helpful for reducing "acid rain," but reducing SO2 in the upper atmosphere removes the umbrella of protection that reflects solar radiation back to space and shields the earth from the warming effect of greenhouse gases. Reducing emissions of air pollutants will either warm or cool the climate. Therefore, integrating air quality and climate stabilization goals in environment policy design would be highly beneficial.
Mauzerall described the "co-benefits concept", pursuant to which strategic reductions in the emissions of greenhouse gases such as can improve air quality in several ways. Because methane is a precursor of ozone, reducing methane reduces harmful ozone in the upper atmosphere. In addition, if you reduce the concentration of methane it can benefit climate, health, and agriculture.. Strategic reductions in the emissions of air pollutants such as black carbon can benefit climate, and reductions of others (i.e. sulfate and SO2) will decrease warming. Therefore, the goal is to identify emission reduction strategies which simultaneously improve air quality and reduce climate warming.
Zaelke explained that black carbon is a component of soot, the small particulate matter emitted from the incomplete combustion of fossil fuels, biofuels and biomass. Unlike carbon dioxide, which remains in the atmosphere for extended periods of time and has long-term effects, black carbon emissions have a shorter-term impact (e.g. several days) on the environment. He suggested that 2005 emissions of this substance can be correlated to a 2.4 degrees Celsius warming worldwide, which is a danger for global public health. Zaelke explained that black carbon causes fifty percent of the warming in the Artic. He also mentioned that bio-char, which is an organic material similar to charcoal, could lead to permanent carbon storage and possibly remove all of CO2 emitted since the pre-industrial revolution era from the atmosphere
Zaelke suggested that programs to reduce black carbon emissions could have a significant impact on global warming because it is the second or third strongest climate forcing agent and remains in the atmosphere for only a few days. Reducing emissions would decrease the presence of black carbon in the atmosphere and have an almost immediate climate mitigation impact. Conversely, temperature reductions by reducing CO2 emissions would take several decades. For this reason, Zaelke said reductions in black carbon emissions are essential.
O'Keefe began by noting that the World Health Organization has reported that India and China have the highest death rates due to air pollution. However, China has made progress by mandating the removal of lead from gasoline and actively pursuing electrical hybrid vehicle technology. O'Keefe noted that the ultimate goal is to provide new science in local populations that can help fight air pollution. It is important to inform small communities in China regarding western studies on air pollution and the significant impact of air pollution on human health. This linkage could give the communities incentives for the creation of new energy.
One audience member asked about the prospect of U.S.-China cooperation and it was noted that opportunities for bilateral engagement do matter. Turner commented that NGOs have been instrumental in environmental cooperation between U.S. and China. In addition, EPA has helped to establish regional collaboration in China when it comes to the environment. O'Keefe mentioned that USAID withdrew all funding on air quality a few years ago and it was a big loss.
Another question was about China's position on cap and trade programs. Turner answered that there is a big push in China for energy conservation laws and local governments are feeling the pressure. Since there are many dynamics in China domestically, the health impacts are resonating with the Chinese public. Zaelke added that policy has not caught up to the science and cap and trade is still an experiment at scale. Someone asked if it is confusing to policy makers when scientists shift the focus of the climate change debate from targeting CO2 to black carbon. Zaelke said that it is more important to look at broader sources and is the science underlying the argument for reductions in black carbon is becoming more and more accepted and policymakers are beginning to understand.
By Yoonhee Rho
David Klaus, Consulting Director, Wilson Center on the Hill