Monday, March 22, 2010

CO2 and its local impact

One of the difficulties with looking at CO2 emissions is the lack of a "local impact" of CO2. This causes problems both theoretically and empirically.

My recent paper "Stochastic Divergence or Convergence of Per Capita Carbon Dioxide Emissions: Re-examining the Evidence" potentially suffers from this problem.

Perhaps now "motivating" such a piece of work will be a little easier.

Cities hit more by CO2 emissions

Carbon dioxide, the main greenhouse gas driving climate change, is a global problem – but a study at Stanford University in California shows it is also harmful locally, affecting city dwellers much more than their rural cousins, as a result of CO2 “domes” that develop over urban areas.

Mark Jacobson, director of Stanford’s Atmosphere/Energy Programme, found that domes of higher CO2 concentrations cause local temperature increases, which in turn increase the amount of local air pollutants such as low-level ozone and soot particles in urban air. He estimated that urban CO2 caused 50-100 excess deaths a year in California and 300-1,000 for the US, on top of the health effects of other pollutants.

The study, published in the journal Environmental Science and Technology, provides the first scientific basis for controlling local CO2 emissions based on their damage to health, according to Prof Jacobson. It also exposes an oversight in current cap-and-trade proposals for reducing CO2 emissions.

“The cap-and-trade proposal assumes there is no difference in the impact of CO2, regardless of where it originates,” Prof Jacobson said. “This study contradicts that assumption. It doesn’t mean you can never do something like cap and trade – it just means that you need to consider where the CO2 emissions are occurring.”


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