Why the world needs fewer cars in the age of climate change, and how we can get around joyfully without them. With the upcoming 21st UN Climate Summit in Paris (COP21) this December promising to be a multi-lane highway towards a low carbon society, it begs the question how this lofty aspiration squares with a 1.2 billion fleet of automobiles worldwide, projected to grow to 2 billion by 2035 and double…