2014 was the hottest year on record. What's next for climate change policy and economics?

Ten million phones bought, 56 million cards stolen and a lot of loan defaults.

Urban bike share's low-carbon, high-tech vision … requires a few gas guzzlers.

U.S. clean tech is finding big opportunities cleaning up China's environment.

The average Nigerian uses about 1/5 the energy of the average American.

Europe has been in the forefront of limiting carbon emissions. Do new European Union rules represent backsliding?

We buy (and throw away) our mobile phones at an alarming rate.

Britain's government supports fracking as a source of cheap gas and jobs but his plans are meeting stiff resistance in the countryside, where New Age protesters and rich conservative country-dwellers want none of it.

Many companies focus on short-term results. The CEO of consumer-products giant Unilever, Paul Polman, says long-term strategic planning builds better businesses.