scholarly journals Projections of atmospheric mercury levels and their effect on air quality in the United States

2013 ◽  
Vol 13 (8) ◽  
pp. 20165-20194
Author(s):  
H. Lei ◽  
D. J. Wuebbles ◽  
X.-Z. Liang ◽  
Z. Tao ◽  
S. Olsen ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Warming ◽  
Global Climate Change ◽  
Wet Deposition ◽  
Global Climate ◽  
The United States ◽  
Atmospheric Mercury ◽  
Western Us ◽  
The Us ◽  
Ipcc Sres

Abstract. The individual and combined effects of global climate change and emissions changes from 2000 to 2050 on atmospheric mercury levels in the US are investigated by using the global climate-chemistry model, CAM-chem, coupled with a mercury chemistry-physics mechanism (CAM-Chem/Hg). Three future pathways from the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) are considered, with the A1FI, A1B and B1 scenarios representing the upper, middle and lower bounds of potential climate warming, respectively. The anthropogenic and biomass burning emissions of mercury are projected from the energy use assumptions in the IPCC SRES report. Natural emissions from both land and ocean sources are projected using dynamic schemes. The zonal mean surface total gaseous mercury (TGM) concentrations in the tropics and mid-latitudes of the Southern Hemisphere are projected to increase by 0.5–1.2 ng m-3 in 2050. TGM concentration increases are greater in the low latitudes than they are in the high latitudes, indicative of a larger meridional gradient than in the present day. In the A1FI scenario, TGM concentrations in 2050 are projected to increase by 2.1–4.0 ng m-3 for the eastern US and 1.4–3.0 ng m-3 for the western US. This pattern corresponds to potential increases in wet deposition of 10–14 μg m-2 for the eastern US and 2–4 μg m-2 for the western US. The increase in Hg(II) emissions tends to enhance wet deposition and hence increase the risk of higher mercury entering the hydrological cycle and ecosystems. In the B1 scenario, mercury concentrations in 2050 are similar to present level concentrations; this indicates that the domestic reduction in mercury emissions is essentially counteracted by the effects of climate warming and emissions increases in other regions. The sensitivity analyses presented show that anthropogenic emissions changes contribute 32–53% of projected mercury air concentration changes, while the independent contribution by climate change accounts for 47–68%. In summary, global climate change could have a comparable effect on mercury pollution in the US to that caused by global emissions changes.

scholarly journals Projections of atmospheric mercury levels and their effect on air quality in the United States

2014 ◽  
Vol 14 (2) ◽  
pp. 783-795 ◽  
Author(s):  
H. Lei ◽  
D. J. Wuebbles ◽  
X.-Z. Liang ◽  
Z. Tao ◽  
S. Olsen ◽  
...  
Keyword(s):  
Climate Change ◽  
United States ◽  
Climate Warming ◽  
Wet Deposition ◽  
Global Climate ◽  
The United States ◽  
Atmospheric Mercury ◽  
Western Us ◽  
Natural Emissions ◽  
Ipcc Sres

Abstract. The individual and combined effects of global climate change and emissions changes from 2000 to 2050 on atmospheric mercury levels in the United States are investigated by using the global climate-chemistry model, CAM-Chem, coupled with a mercury chemistry-physics mechanism (CAM-Chem/Hg). Three future pathways from the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) are considered, with the A1FI, A1B and B1 scenarios representing the upper, middle and lower bounds of potential climate warming, respectively. The anthropogenic and biomass burning emissions of mercury are projected from the energy use assumptions in the IPCC SRES report. Natural emissions from both land and ocean sources are projected by using dynamic schemes. TGM concentration increases are greater in the low latitudes than they are in the high latitudes, indicative of a larger meridional gradient than in the present day. In the A1FI scenario, TGM concentrations in 2050 are projected to increase by 2.1–4.0 ng m−3 for the eastern US and 1.4–3.0 ng m−3 for the western US. This spatial difference corresponds to potential increases in wet deposition of 10–14 μg m−2 for the eastern US and 2–4 μg m−2 for the western US. The increase in Hg(II) emissions tends to enhance wet deposition and hence increase the risk of higher mercury entering the hydrological cycle and ecosystem. In the B1 scenario, mercury concentrations in 2050 are similar to present level concentrations; this finding indicates that the domestic reduction in mercury emissions is essentially counteracted by the effects of climate warming and emissions increases in other regions. The sensitivity analyses show that changes in anthropogenic emissions contribute 32–53% of projected changes in mercury air concentration, while the independent contribution by climate change and its induced natural emissions change accounts for 47–68%.

China-US deal sets stage for new climate change regime

2015 ◽  
Keyword(s):  
Climate Change ◽  
United States ◽  
Developing Countries ◽  
Global Climate Change ◽  
Global Climate ◽  
The United States ◽  
Content Type ◽  
Bilateral Agreement ◽  
The Eu ◽  
Game Changer

Significance The United States has already committed, in an unprecedented deal with China in November 2014, to reducing its emissions to 26-28% below 2005 levels by 2025 (an improvement on its previous 17% goal). China in return pledged that its emissions would peak around 2030. This agreement is a game-changer for combating global climate change, since the two countries are the world's largest sources of carbon emissions, together accounting for 40% of the total, and were not covered under the now-expired Kyoto Protocol. Impacts Washington is poised to reclaim its place, lost after Kyoto, as a leader in global efforts against climate change. US-China climate cooperation initiatives could serve as templates for other developing countries. There are new opportunities for trilateral cooperation involving the EU. Fears that the bilateral agreement makes the UNFCCC obsolete are unwarranted, but it could preclude more ambitious efforts.

Knowledge and governance in the digital age: The politics of monitoring planetary life

First Monday ◽  
2006 ◽  
Author(s):  
Robert Latham
Keyword(s):  
Climate Change ◽  
United States ◽  
Global Climate Change ◽  
Disease Transmission ◽  
Global Climate ◽  
The United States ◽  
Monitoring Systems ◽  
Processing Technologies ◽  
Building Monitoring ◽  
The World

Planetary phenomena, such as global climate change and transborder disease transmission, are increasing subject to monitoring aided by advances in surveillance and data processing technologies. The most powerful governments of the world, especially the United States, are building monitoring systems they can control. Communities and activists around the world face a fundamental choice: become involved in shaping those systems so they better serve the needs and interests of the world’s population or build their own independent, unofficial monitoring systems.

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