This one's a bit comical. We're all aware that reducing your speed while driving leads to fuel savings and reduced emissions, but no one in their right mind in Washington is going to suggest we lower speed limits. That's apparently not so in Britain. Auto Express
that last week, while the Members of the British Parliament were discussing climate change, Nia Griffith, a Labour Party MP (Member of Parliament), suggested an extremely cost-effective way of reducing the speed limit on all roads. She said they should simply change the meaning of the country's speed limit signs from miles per hour to kilometers per hour. This would slash speed limits by about five-eights without having to replace a single sign or post.
Auto Express didn't speculate as to whether Griffith's suggestion would turn into a bill and passed into law (or whatever legal terminology they use across the pond), but she did apparently get some support from the Liberal Democrat MP Lynne Featherstone.
[Source: Auto Express]