Despite $2T invested over the past 20 years in renewable energy projects, carbon dioxide...

|By:, SA News Editor

Despite $2T invested over the past 20 years in renewable energy projects, carbon dioxide emissions per unit of energy consumed have fallen by less than 1%, the IEA reports. A main reason is the continued success of coal, the fuel of choice for much of the world despite being in retreat in the U.S. and perhaps even in China. Until low-carbon alternatives get cheaper, coal will continue to be favored.