Paul Krugman supports the use of a carbon tax or cap and trade to reduce carbon emissions. Conservatives should support these market based mechanisms to reduce carbon emissions but most of them have been captured by the fossil fuel industry which is fearful of government intervention in their market. He is also critical of left leaning advocates who argue that we cannot reduce carbon emissions and grow the economy at the same time. Krugman believes that we can alter the mix of output which enables us to do both. A services economy is less energy intensive.
What really attracted Krugman's attention, however is graph which shows that solar energy prices have been dropping so rapidly that it is on its way to replacing the use of coal to provide electricity.