Clearer Skies Over China: Reconciling Air Pollution, Climate, and Economic Goals


The China Project's economists, engineers, atmospheric scientists, and health scientists at both Harvard and Tsinghua have integrated the economics-engineering-health framework developed in Clearing the Air with the Project's GEOS-Chem atmospheric model of China, tested against observations by satellite and ground stations. This long-intended Project integration is possible due to advances in the resolution of national emission inventories by Tsinghua researchers, who have now refined, updated, and integrated them as Harvard China Project post-docs. The improved spatial and sector resolution of emission inventories makes the linking of a sector-based economic model and a spatially-resolved atmospheric model feasible. (The emission inventory research is summarized towards the end of the atmospheric modeling page of this website.)

The result is an advance in understanding the full atmospheric and related effects of emission control and energy policies shaping the Chinese economy. This model integration allows the team to better quantify the effects of complex secondary pollutants like ozone and sulfates on public health, agricultural productivity, and the economy, and potentially of black carbon and sulfates on radiative forcing. The multi-disciplinary team first completed assessment of two policies using the newly comprehensive framework, looking backwards to the years 2006-2010 to take advantage of more complete datasets:

          • A carbon tax of 100 yuan/ton of carbon (roughly US$4/ton CO2), in which avoided local pollution and health damages are a co-benefit of GHG control; and

          • The ambitious sulfur control measures of the 11th Five Year Plan (2006-2010), in which effects on carbon emissions are a co-benefit of local pollution control.

This comprehensive framework was then used to evaluate a variety of carbon tax structures in China looking forward to 2013-2020, including:

          • different tax levels;

          • different time-paths of tax implementation;

          • different revenue uses, including lump-sum rebates to consumers, revenue-neutral reductions of distortionary existing taxes, and support for emission-intensive, trade-exposed industries; and

          • different assumptions about carbon prices in the rest of the world.

A new edited volume, Clearer Skies Over China: Reconciling Air Quality, Climate, and Economic Goals (Nielsen and Ho 2013, MIT Press) reports results of the scenarios for both 2006-2010 and 2013-2020. The results were also the subject of an op-ed in the Sunday Review of the New York Times by Chris P. Nielsen and Mun S. Ho of the China Project. 

This complex collaboration was seed-funded by the Harvard China Fund, and has been generously supported by grants from the China Sustainable Energy Program of the Energy Foundation, a Harvard fund for student and post-doctoral fellowships, and the Harvard Weatherhead Center for International Affairs. The economics component is now separately supported by an award from the Cheung Yan Fund of the Harvard Department of Economics.

Funding allowing, the team is also anxious to investigate the full costs and benefits of other approaches China is implementing or considering to limit its emissions of atmospheric pollutants and GHGs. These include additional possible strategies to achieve its 2020 carbon intensity target:

          • carbon cap and trade;

          • energy efficiency policies; and

          • renewable energy policies and strategies.

These approaches also include equally important policy strategies to reduce local and regional air pollution:

          • NOx controls in the 12th Five Year Plan (2011-2015);

          • potential control of other environmentally potent species, including ammonia and volatile organic compounds (VOCs).

The team is also preparing to broaden the collaboration further, to draw in additional past and current research capacities separately developed by the China Project. This includes a regional, bottom-up, technology choice model of the Chinese electric power sector originally developed by Murray (1996) and Murray and Rogers (1998), later reconciled with the Project's economic model by Cao (2007), and now gradually being updated to current conditions.