World leaders attend the United Nations Climate Change Conference in Le Bourget

Russian President Vladimir Putin, right, and South Korea's President Park Geun hye seen together at COP21 UN Conference on Climate Change in Paris, France, on Monday (AP Photo)

Indian Prime Minister Narendra Modi delivers a speech during the 'Mission Innovation Accelerating the Clean Energy Revolution' meeting at the COP2, United Nations Climate Change Conference on Monday (AP Photo)

Bill Gates delivers addresses world leaders during the 'Mission Innovation Accelerating the Clean Energy Revolution' meeting at the COP2, United Nations Climate Change Conference, in Le Bourget, north of Paris (AP Photo)

French President Francois Hollande delivers a speech during the 'Mission Innovation Accelerating the Clean Energy Revolution' meeting at the COP2, United Nations Climate Change Conference, in Le Bourget (AP Photo)

French President Francois Hollande, center, shakes hands with Indian Prime Minister Narendra Modi, left, as US President Barack Obama leaves the 'Mission Innovation Accelerating the Clean Energy Revolution' meeting at the COP2, United Nations Climate Change Conference (AP Photo)

India's Prime Minister Narendra Modi addresses world leaders at the COP21, United Nations Climate Change Conference (AP Photo)

US President Barack Obama meets Microsoft CEO Bill Gates during the 'Mission Innovation Accelerating the Clean Energy Revolution' meeting at the COP2, United Nations Climate Change Conference, in Le Bourget, north of Paris on Monday (AP Photo)

US President Barack Obama delivers his speech at the 'Mission Innovation Accelerating the Clean Energy Revolution' meeting at the COP2, United Nations Climate Change Conference (AP Photo)

French President Francois Hollande and US President Barack Obama attend the 'Mission Innovation Accelerating the Clean Energy Revolution' meeting at the COP2, United Nations Climate Change Conference, in Le Bourget, north of Paris on Monday (AP Photo)

French President Francois Hollande, right, seen talking to Israeli Prime Minister Benjamin Netanyahu at the COP21, United Nations Climate Change Conference, in Le Bourget on Monday (AP Photo)