National: Germany’s Schwarze Pumpe is the world’s first coal-fired plant ready to capture and store its own carbon dioxide emissions. Matthias Rietschel / AP Photo If the world wants to limit global warming to 2°C by 2050, it will have to leave three quarters of its proved reserves of oil, gas and coal in the ground, according to two climatological studies. In a paper published this week in the British scientific journal Nature, scientists from the Potsdam Institute of Climate Impact …