A tricky question

Authors: Kerstin Schnatz and Philipp Bilsky, Camera-Operatpr: Philipp Bilsky

What if there was only one thing the world could do to stop climate change? Or at least to slow it down? What would be the most important step to take? How would you decide? That’s what we asked visitors at the Rio+20 Earth Summit, the United Nations Conference on Sustainable Development in Rio de Janeiro. Apparently a tricky question to answer.