This article by Bill McKibben puts the problem of limiting global warming into a new context. There are three numbers that tell the story. There has been a commitment to a 2C degree limit on a global temperature increase. The implies a 565 gigaton limit on carbon emissions. There are 2,279 gigatons of fossil fuels available in the reserves of energy firms and nations that act as energy firms. That represents around $27 trillion worth of reserves that are incorporated into the stock prices of the energy firms. Moreover, firms like Exxon plan to spend $37 billion through 2016 to explore for additional reserves. We have met the enemy and it the energy industry. There is no other industry in the world that is allowed to dump its wastes without having to pay for it. According to McKibben it is a rogue industry.
McKibben does not believe that there is enough time to change consumer habits so that consumption can be limited enough by consumer rationing of carbon. It will be up to governments and energy companies to take the necessary actions. A carbon tax would be the best way to achieve the goal of a 2C degree limit on warming but energy companies do not want to see the value of their reserves affected by a higher price for carbon emissions.
We understand the story by using the three numbers that McKibben provided. The rest of the article is a description of the politics implied by the difference between the 565 gigaton carbon limit and the 2,279 gigaton carbon emissions from known fossil fuel reserves.