Early Warning Signs of Global Warming

Published Jul 16, 2008

"An increasing body of observations gives a collective picture of a warming world and other changes in the climate system."

Intergovernmental Panel on Climate Change (IPCC), 2001

Frustrated because a friend or colleague says global warming is the future's problem? Compelling new evidence demonstrates that global warming is already under way with consequences that must be faced today as well as tomorrow. The evidence is of two kinds:

  • Fingerprints of global warming are indicators of the global, long-term warming trend observed in the historical record. They include heat waves, sea-level rise, melting glaciers and warming of the poles.
  • Harbingers are events that foreshadow the impacts likely to become more frequent and widespread with continued warming. They include spreading disease, earlier spring arrival, plant and animal range shifts, coral reef bleaching, downpours, and droughts and fires.

UCS is taking steps to bring this evidence to the public's attention, with the goal of building support for action to reduce the heat-trapping gas emissions that cause global warming. Working with other environmental organizations, we have developed--and recently updated--a world map, viewable online and also available as a poster, that shows where the fingerprints and harbingers of global warming have occurred in recent years. By showing the local consequences of climate change, it brings the message home effectively.

Since its release in 1999, the map has been featured in several news stories, hand-delivered to every member of Congress, accessed by students across the country, and been visited online by people throughout the world. Due to the popularity of the map, UCS undertook a revision, and added 66 new points in January 2003. Most of these new points are in the developing world, for which we had little data in 1999. Below is a list of links to the home page of the map project (www.climatehotmap.org), supplemental information about the map, and a curriculum guide created for the map.



Supplemental material

Related resources