How can we cope with global warming and the challenges it poses? The Intergovernmental Panel on Climate Change (IPCC) has just completed its fourth assessment of the science of climate change, its impacts and possible solutions. The panel of 2,500 scientists and other experts declared manmade warming "unequivocal" and wrote that it could lead to climate changes that are "abrupt and irreversible."

Next week the world's governments are set to gather in Bali to begin negotiating an international treaty to reduce greenhouse gas emissions that will succeed the much-debated Kyoto Protocol. The science is clear that the earth is heating up and will continue to do so—with potentially catastrophic consequences—unless we change our ways. What is unclear is how best to go about reining in our globe-warming pollution. Some argue for a fund for future clean technology while others prefer to focus on reducing pollution from present sources.

This special report explores the latest findings on the impact of human activity on Earth's climate—from the melting of Arctic ice to the potential spread of disease. It also explores the more pertinent question of where we can go from here.–The Editors

State of the Science: Beyond the Worst Case Climate Change Scenario

Earth in Heat: 10 Views of a Warming World [Slideshow]

Climate Change Impacts [Interactive map]

Clash: What Will Climate Change Cost Us? [Q&A]

10 Solutions for Climate Change

Scientific American's Climate Change Coverage