Impacts of the Minamata Convention on Mercury Emissions and Global Deposition from Coal-Fired Power Generation in Asia

Abstract

ABSTRACT:We explore implications of the United Nations Minamata Convention on Mercury for emissions from Asian coal-fired power generation, and resulting changes to deposition worldwide by 2050. We use engineering analysis, document analysis, and interviews to construct plausible technology scenarios consistent with the Convention. We translate these scenarios into emissions projections for 2050, and use the GEOS-Chem model to calculate global mercury deposition. Where technology requirements in the Convention are flexibly defined, under a global energy and development scenario that relies heavily on coal, we project ∼90 and 150 Mg·y −1 of avoided power sector emissions for China and India, respectively, in 2050, compared to a scenario in which only current technologies are used. Benefits of this avoided emissions growth are primarily captured regionally, with projected changes in annual average gross deposition over China and India ∼2 and 13 μg·m −2 lower, respectively, than the current technology case. Stricter, but technologically feasible, mercury control requirements in both countries could lead to a combined additional 170 Mg·y −1 avoided emissions. Assuming only current technologies but a global transition away from coal avoids 6% and 36% more emissions than this strict technology scenario under heavy coal use for China and India, respectively.

Observed decrease in atmospheric mercury explained by global decline in anthropogenic emissions

“…), but total Hg emissions over this period increased less (5.8% y −1 ) because of the implementation of FGD (21). This previously unaccounted shift in speciation implies greater declines in near-field Hg deposition than previously estimated.…”

“…Recent work suggests weaker growth in Chinese emissions than previously estimated because of improved data on new coal-fired utilities with flue gas desulfurization (FGD) (20,21). Also, the increasing trend in ASGM emissions appears to be a spurious effect of improved reporting (9).…”

“…The fraction of coal-fired utilities with FGD increased from 20% to 46% between 1990 to 2002 in Western Europe and from 30% to 70% between 1990 and 2005 in Japan, resulting in a total cumulative decrease of 200 Mg Hg II from developed countries including the US (25,26). In China, the fraction of coal-fired utilities with FGD capacity increased from zero in 2000 to 86% in 2010, resulting in a drop in annual Hg II emissions of 30% and 250 Mg cumulatively between 1990 and 2010 (21). The growth in energy demand in China has led to a rapid increase in coal combustion (11% y −1…”

Benefits of mercury controls for the United States

“…The largest sources of anthropogenic mercury emission are stationary coal combustion, artisanal and small-scale gold mining, and metals production (18). Under NP, emissions are projected to more than double, largely as a result of growth in coal use in Asia (19); thus, the main differences in policy and NP projections depend on assumptions about emission controls for coal (20). Air quality abatement technologies such as flue gas desulfurization can capture mercury as a cobenefit.…”

Splitting the South: China and India’s Divergence in International Environmental Negotiations

“…Projections suggested that they would continue to be the leading emitters. Given the substantial emissions from these two countries alone, cooperation from both China and India was essential to addressing mercury globally (Giang et al 2015).…”