Contents

09 February 2007
Vol 315, Issue 5813

About The Cover

Cover image expansion

COVER A solar farm collects a tiny fraction of the 174,000 terawatts of energy striking Earth in the form of sunlight. In 2005, the rate of global energy consumption was about 16.3 terawatts. See the special section on sustainability and energy beginning on page 781. Photo illustration: Kelly Krause/Science (Images: Getty/Digital Vision)