Renewable energy and greening power production at the source is something that receives more attention than the unsexy energy “efficiency.” The reality is that efficiency is likely to play a much bigger part in cutting greenhouse gas emissions, especially in the short term, says the International Energy Agency:

About 78 percent of CO2 savings were likely to come from more efficient use of energy and 22 percent from cleaner energy sources by 2030, according to the agency.

Mandil said that to avoid one billion tonnes of greenhouse gases a year, the world would need to replace 300 convention coal-fired power plants with zero emission electricity generation every year, or build 150 one-gigawatt nuclear power plants.

That is also the equivalent of multiplying the United States’s current solar power capacity by about 1,300 every year or 200 times the US wind farm capacity.

Efficiency is where it’s at.