Climate Change

Cities as policy labs: L.A. cleans up its smog

With the largest fleet of natural gas buses in the U.S. — about 2,200 — Los Angeles has become a leader in cutting carbon emissions.

Cities as policy labs: New York retools

Find out what makes the largest city in the United States one of the world's greenest, most environmentally friendly cities.
Aerial view of city at meeting of rivers (© AP Images)

Cities as policy labs: Pittsburgh’s towering experiment

Once a declining industrial metropolis with steel mills spewing black smoke and soot into the sky, Pittsburgh has transformed itself into a vibrant green city.
Aerial view of group of people planting shrubs (© Getty Images)

Cities as policy labs: Chicago’s rooftop experiment

Chicago's rooftop gardens reuse water and reduce heat, which can reduce a building's power costs. The city has 418,000 square meters of high-rise greenery.
Rooftop solar panels with skyscrapers in the distance (© AP Images)

Your home + solar panels = distributed generation

Renewable energy resources such as solar and wind have opened up new possibilities for distributed power generation and transmission.
Lava flowing from volcano (© AP Images)

From lava to solar: These renewables are so hot right now

What type of energy do you use? The five dominant sources of renewable energy range from solar and wind to lava and biomass.
Illustration of figures pushing globe up hill (State Dept./D. Thompson)

What’s next for the Paris climate agreement?

After more than 190 countries signed the Paris agreement, it moved toward going into force in only months. What's next for the landmark climate accord?
Planes lining up to take off as a jet is landing (© AP Images)

Countries approve first-ever limits on airline emissions

If the airline industry were a country, it would be the world's seventh-largest carbon polluter. New rules set limits on increases in aircraft emissions.
Sun setting showing shadows of four people walking (© AP Images)

Obama: ‘The world meets the moment’ on climate

The Paris climate agreement will enter into force November 4, after the EU ratified the accord to bring it past a key threshold.