Snow falls over the Wumen Gate of the Forbidden City at night in Beijing February 17, 2009. China took credit on Tuesday for the first snowfall of the winter in Beijing, saying it fired sticks of chemicals into the sky to seed clouds in a bid to end a persistent drought.
Jason Lee / Reuters

Each year, the effects of climate change are coming into sharper focus. Barely a month goes by without some fresh bad news: ice sheets and glaciers are melting faster than expected, sea levels are rising more rapidly than ever in recorded history, plants are blooming earlier in the spring, water supplies and habitats are in danger, birds are being forced to find new migratory patterns.

The odds that the global climate will reach a dangerous tipping point are increasing. Over the course of the twenty-first century, key ocean currents, such as the Gulf Stream, could shift radically, and thawing permafrost could release huge amounts of additional greenhouse gases into the atmosphere. Such scenarios, although still remote, would dramatically accelerate and compound the consequences of global warming. Scientists are taking these doomsday scenarios seriously because the steady accumulation of warming gases in the atmosphere is forcing change in the climate system

This article is part of our premium archives.

To continue reading and get full access to our entire archive, you must subscribe.

  • DAVID G. VICTOR is a Professor at Stanford Law School, Director of Stanford's Program on Energy and Sustainable Development, and an Adjunct Senior Fellow at the Council on Foreign Relations. M. GRANGER MORGAN is Head of Carnegie Mellon University's Department of Engineering and Public Policy and Director of the Climate Decision Making Center. JAY APT is Professor of Engineering and Public Policy at Carnegie Mellon University. JOHN STEINBRUNER is Professor of Public Policy and Director of the Center for International and Security Studies at the University of Maryland. KATHARINE RICKE is a doctoral student at Carnegie Mellon University. Additional materials are available at
  • More By David G. Victor
  • More By M. Granger Morgan
  • More By Jay Apt
  • More By John Steinbruner
  • More By Katharine Ricke