How 5 cities are using technology to reduce the harmful effects of dirty air

Given all the tools and technologies available today, it seems like air pollution ought to be something we can solve – or at least keep from getting worse. But a recent report in the Times of India suggests that an abnormal 152% growth in private vehicles is contributing to dwindling air quality in Hyderabad, the capital city of Telangana in southern India. And in the UK, 16,000 deaths a year are blamed on air pollution, described by Wired as an ongoing crisis. Equally troubling, researchers say climate change will increase the number of deaths from air pollution by hundreds of thousands in coming years. But as you'll read below, it's not all bad news about bad air. – Liz Enbysk

An estimated two million deaths a year globally are due to indoor air pollution, according to the World Health Organization. Outdoor air pollution claims another 1.3 million lives. Children are particularly at risk.

Not everyone agrees how to solve it. Some urban planners will tell you electric cars are the answer. Others advocate car-free zones in central business districts. Making public transit more attractive is another solution. Still others would have everyone riding bikes to work.

Technology offers solutions too – some novel, some tried-and-true. A few examples: