Smart development goals: To get the biggest bang for every buck, paint a bull’s eye on 19 specific targets

When it comes to cooking indoors over open fires, the harmful health effects can be equal to smoking two packs of cigarettes a day. This indoor air pollution plagues nearly nine out of every 10 Bangladeshi households, which use wood and other biofuels to cook inside.

Over time, exposure to smoke from indoor cooking leads to deadly diseases such as lung cancer, stroke, and heart disease. This is why it's the most deadly environmental problem in the world. In Bangladesh, such indoor air pollution is responsible for 10-15 percent of all deaths.

For this Earth Day it is especially important we focus on the world's top priorities. In September, all 193 governments will meet at the UN to set targets for the world for the next 15 years in what is explicitly labeled "Sustainable Development Goals." So, it is worth looking at what we should do first. At my think tank, the Copenhagen Consensus, we've asked 60 teams of top economists including several Nobel laureates to evaluate the economic, social and environmental costs and benefits of the targets, so we can pick the best ones. Here is what we should do in environment.

BBC Radio 4, Today programme   Few things polarise opinion more than the electric car. It is either a great way to save the planet or a really bad way to get from A to B? The Today programme's Evan Davis wanted to find out more, and took a ride in one with an enthusiast and a sceptic. Bjorn Lomborg, the so-called Sceptical Environmentalist, having written a book of that name, has made a career attacking what he thinks are the irrationalities of the green movement. He is not a fan of electric cars. Ian Hobday, who runs Liberty Electric Cars, took Evan and Mr Lomborg for a ride.