Global Sulphur-dioxide Emissions Are Falling – A Good News Climate Story

GLOBE-Net, March 25, 2013 – A new study confirms that global emissions of sulphur dioxide are declining, which is promising from the point of view of pollution, but a fact that could have implications for global warming.

Global sulphur-dioxide emissions have generally been in decline since the mid-70s, though they did increase from 2000 to 2005, and peaked at 112 Tg (trillions of grams) in 2006.  Global SO₂ emissions, estimated at 121 Tg in 1990 declined to 103 Tg by 2010.

However, there is a great deal of variability in emissions abatement performance.  North America and Europe continue to see reduced emissions levels, but increasing levels of emissions are present in Asia and as a consequence of international shipping.

[stextbox id=”custom” float=”true” width=”200″ bcolor=”add3d5″ bgcolor=”add3d5″ image=”null”]Sulphur dioxide emissions have substantial impacts on human health, terrestrial and aquatic ecosystems, and have come under increasing regulation world-wide[/stextbox]

Global emissions in 2010 are estimated to be lower than in 2000 by about 3%. While there is a net increase over 2000-2010 period from the EECCA (Eastern Europe, Caucasus and Central Asia), China, India, and international shipping, these increases were smaller than emission reductions in North America (US and Canada) and Europe, leading to a net decrease in global emissions.

Asia Emisisons Rising

China remains a key SO₂ emissions contributor, but the recent introduction of stricter emission limits followed by an ambitious program of installing flue gas desulfurization technologies in power plants has resulted in a significant decline in emissions from the energy sector and has helped to stabilize total Chinese SO₂ emissions. Notwithstanding this, in recent months, air pollution in Beijing has caused serious health issues.

The second largest emitter in Asia is India where there is no sign of slowing growth of emissions. This is largely due to an expansion of coal consumption in the power sector where current legislation does not require installation of flue gas desulfurization (FGD).

Although, total Indian SO₂ emissions are not as large as that of China, they exceeded in 2010 emissions of US and have grown by over 40% since 2005. If these trends continue, India will become an increasingly important contributor to global sulphur dioxide emissions, although emissions in 2011 were estimated to be only a third of China’s total.

Comparable mitigation strategies are not yet present in other Asian countries and industrial sectors in general,

International Shipping

Emissions from international shipping increased from 6.8 Tg in 2000 to 13.6 Tg in 2010. These emissions are expected to start declining following an international agreement to reduce the sulphur content of fuel oil.

Declining emissions from both China, still the world’s largest source of SO2 emissions, the planned decrease in shipping emissions, and continued decreases industrialized countries are likely to lead to a further net decrease in global SO2 emissions in the future. (See GLOBE-Net article “ International shipping could cut air pollutants and greenhouse gases“

This will have regional and global consequences, decreasing the net negative radiative forcing from sulphur dioxide emissions – that is ‘masking’ some of the impact of increasing greenhouse gases.

The continued decline in global SO₂ emissions likely will result in an increase in the rate of future climate change.