Greenhouse gas emissions

Chinese President Xi Jinping says his country will aim to stop adding to the global warming problem by 2060.

Large cities like San Francisco and New York, along with smaller cities and counties in California, want the big oil companies to pay for the harm their products have caused in the form of rising seas, floods and drought. Better science and clear evidence of deception give these lawsuits far more traction than in the past.

Tropical forests have historically absorbed excess carbon dioxide, but new research indicates that these areas have become a net source of CO2.

President Trump may have decided to pull the US out of the Paris climate agreement, but America’s airlines are still bound by a separate agreement that regulates global warming gases from international flights. The Trump administration is reviewing the deal, but US air carriers say pulling out would hurt their competitiveness and raise costs.

Prior to the signing of the Paris climate agreement, few nations saw India as a leader in climate policy. But in 2015, the world’s third-biggest CO2 emitter began a breathtaking transformation, embracing renewable energy and slashing growth in carbon emissions. Now, the country of 1.3 billion people is a leader in clean energy in the developing world.