Burney is examining a
similar trade - off between sulfur and black carbon in the United States, as coal - fired
electricity plants shift to cleaner natural gas, which emits half as much CO2 as coal per unit of
electricity.
For example, climate scientists are least well - placed to make a judgement on the timing and quantum of CO2 emissions that are exported from, say, Spain, as a result of higher
electricity prices there resulting from wind and solar, and certainly very poorly placed to opine on the impact on global GHG emissions of cap - and -
trade or any
similar EU or even EU / USA - wide policy.