In a hole?

摘要

Many plans for reducing the world's emissions of carbon dioxide-at least, those plans formulated by environmentalists who are not of the hair-shirt, back-to-the-caves persuasion-involve peppering the landscape with wind turbines and replacing petrol-guzzling vehicles with electric ones charged up using energy gathered from renewable resources. The hope is that the level of CO., in the atmosphere can thus be kept below what is widely agreed to be the upper limit for a tolerable level of global warming, 450 parts per million.