Susan Phillips

Beneath the streets of hundreds of North America's oldest cities lies a network of pipes delivering steam heat to office buildings and hospitals. These steam loops could be a clean energy solution.

Beneath the streets of hundreds of North America's oldest cities lies a network of pipes delivering steam heat to office buildings and hospitals. These steam loops could be a clean energy solution.

The Postal Service plans to replace about 160,000 gas-guzzling delivery trucks, but just a fraction will be electric. Advocates and states say going electric is aligned with climate change goals.

The Biden administration has opened the East Coast to massive offshore wind development. But it will happen in some of the country's most fertile fishing grounds, and that's set up a growing battle.

Fifteen states are challenging the decision, arguing that the risk of explosion puts lives in danger. For one project, highly flammable gas will travel 200 miles through a busy East Coast corridor.

Pennsylvania is a major state for drilling natural gas. President Trump has made fracking a significant issue of his campaign in the swing state, but it's unclear how much it may help him.

Across the country, new gas pipelines have met political opposition, protests and lawsuits. In Pennsylvania, one major project has also sparked criminal investigations.

Chemical experts say recent refinery explosions could have been far more devastating if deadly hydrogen fluoride was released. Some are calling for a ban on the chemical.

Japan doesn't think battery electric cars are the only future for transportation. It is investing millions to ramp up production of hydrogen fuel cell vehicles, citing their convenience for consumers.

Many major airports are on low-lying coastal land where flooding is getting worse. They're building walls, berms and other barriers to try to keep planes and people moving.