China’s Smog Clouds May Prevent Global Warming

I’ve posted articles in the past linking the clean air legislation in the west with more sunshine and therefore more warming. Here is a paper arguing the opposite: the lack of clean air in China is cooling the globe.

China is responsible for just 10 per cent of man-made global warming, despite emitting more than one quarter of the world’s greenhouse gases, a new study claims.

The study found sulphate and nitrate aerosols emitted by burning fossil fuels had a cooling effect that offset much of the warming caused by greenhouse gas emissions of carbon dioxide, methane and black carbon.

As a result, while China’s consumption of fossil fuels and its carbon emissions had increased significantly over the past decades, a corresponding increase in aerosol emissions meant its contribution to man-made climate change had remained largely unchanged since the pre-industrial period.

The study was led by Professor Li Bengang at Peking University and published in Nature.

http://www.scmp.com/news/china/policies-politics/article/1929306/chinas-smog-clouds-have-silver-lining-they-may-help

Advertisements

2 thoughts on “China’s Smog Clouds May Prevent Global Warming

  1. ATMOSPHERIC CARBON DIOXIDE AND AEROSOLS:
    Effects of Large Increases on Global Climate.

    Abstract.

    Effects on the global temperature of large increases in carbon dioxide and aerosol densities in the atmosphere of Earth have been computed. It is found that, although the addition of carbon dioxide in the atmosphere does increase the surface temperature, the rate of temperature increase diminishes with increasing carbon dioxide in the atmosphere. For aerosols, however, the net effect of increase in density is to reduce the surface temperature of Earth. Becuase of the exponential dependence of the backscattering, the rate of temperature decrease is augmented with increasing aerosol content. An increase by only a factor of 4 in global aerosol background concentration may be sufficient to reduce the surface temperature by as much as 3.5 deg.K. If sustained over a period of several years, such a temperature decrease over the whole globe is believed to be sufficient to trigger an ice age.

    The rate at which human activities may be inadvertently modifying the climate of Earth has become a problem of serious concern . In the last few decades the concentration of CO2 in the atmosphere appears to have increased by 7 percent . During the same period, the aerosol content of the lower atmosphere may have been augmented by as much as 100 percent .

    How have these changes in the composition of the atmosphere affected the climate of the globe? More importantly, is it possible that a continued increase in the CO2 and dust content of the atmosphere at the present rate will produce such large-scale effects on the global temperature that the process may run away, with the planet Earth eventually becoming as hot as Venus (700 deg. K.) or as cold as Mars (230 deg. K.)?

    We report here on the first results of a calculation in which separate estimates were made of the effects on global temperature of large increases in the amount of CO2 and dust in the atmosphere. It is found that even an increase by a factor of 8 in the amount of CO2, which is highly unlikely in the next several thousand years, will produce an increase in the surface temperature of less than 2 deg. K.

    However, the effect on surface temperature of an increase in the aerosol content of the atmosphere is found to be quite significant. An increase by a factor of 4 in the equilibrium dust concentration in the global atmosphere, which cannot be ruled out as a possibility within the next century, could decrease the mean surface temperature by as much as 3.5 deg. K. If sustained over a period of several years, such a temperature decrease could be sufficient to trigger an ice age!

    Schneider S. & Rasool S., “Atmospheric Carbon Dioxide and Aerosols – Effects of Large Increases on Global Climate”, Science, vol.173, 9 July 1971, p.138-141

    Those results were bases on a climate model developed by none other than James Hansen, incidentally.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s