New Scientist: Oil giant Exxon Mobil has promised to reveal how much of its fossil fuel reserves could become worthless if governments agree to cut greenhouse gas emissions. It is the first major fossil fuel company to declare the size of its exposure to the so-called carbon bubble - the over-valuation of fossil fuel companies that could result if their assets are left unused.
To save ourselves from the worst impacts of global warming, we have to leave fossil fuels in the ground instead of burning them. But...