[单项选择]Today, world leaders are discussing climate change and what-if anything- can be done to combat global warming．Extreme weather conditions have brought home the fact that our climate is changing-and changing fast. It may be easy to be fatalistic about it, but the truth is that although we humans have caused the problem, we also have the solution. " Think global and act local, " said Friends of the Earth founder David Bower. In many small but important ways we can make a difference. Here are my top tips for how to begin:
Count your food miles. What you eat and where you buy it affects global emissions. Pollution from transport is the fastest growing source of carbon dioxide emissions, so it is madness to fly out-of-season vegetables across the world to supermarkets. We should lobby supermarkets for a system of classifying food according to the distance traveled: 0 for local food, 1 for British，2 for Europe, and 3 for intercontinental.
Turn off anything that winks at you. A video
A. his concern over climate change
B. his optimism in finding a way out
C. the necessity of global actions
D. the difficulty in reaching an agreement