U.S. and China, who produce 38 percent of the world's carbon dioxide emissions, have joined the Paris accord to keep the Earth's temperature from rising.
Nearly 200 countries took a key step in the fight against global warming by phasing out a chemical used in air conditioners and refrigerators.
Air quality in California cities improved through strong policies, technology and local collaborative action.
Even before nearly 200 countries reached the historic Paris climate agreement in 2015, credit rating agencies had been evaluating companies' climate risk.
Cities have an advantage for improving air quality. Their experiences In developed countries can benefit cities in developing countries.
What does grid parity have to do with climate change? Everything. As the cost of renewable energy drops, so does the dependence on traditional energy.
Sempra Energy's new solar array will supply 14 Navy and Marine Corps installations one-third of their electricity needs for the next 25 years.
Celebrities use their popularity to support environmental efforts. What can you do to #ActOnClimate?