An Abrupt Climate Change Scenario and Its Implications for United States National Security

October 2003

by Peter Schwartz and Doug Randall

"In 2003, the Pentagon hired Peter Schwartz from "Global Business Network," a scenario-planning think tank, to examine all available research and write a report about a plausible scenario on the national security implications of the threat." [Source]

Full report

Imagining the Unthinkable

"... In this report ... we outline an abrupt climate change scenario patterned after the 100- year event that occurred about 8,200 years ago. This abrupt change scenario is characterized by the following conditions:

The report explores how such an abrupt climate change scenario could potentially de-stabilize the geo-political environment, leading to skirmishes, battles, and even war due to resource constraints such as:
  1. Food shortages due to decreases in net global agricultural production
  2. Decreased availability and quality of fresh water in key regions due to shifted precipitation patters, causing more frequent floods and droughts
  3. Disrupted access to energy supplies due to extensive sea ice and storminess
As global and local carrying capacities are reduced, tensions could mount around the world, leading to two fundamental strategies: defensive and offensive. Nations with the resources to do so may build virtual fortresses around their countries, preserving resources for themselves. Less fortunate nations especially those with ancient enmities with their neighbors, may initiate in struggles for access to food, clean water, or energy. Unlikely alliances could be formed as defense priorities shift and the goal is resources for survival rather than religion, ideology, or national honor. This scenario poses new challenges for the United States, and suggests several steps to be taken: There are some indications today that global warming has reached the threshold where the thermohaline circulation could start to be significantly impacted. These indications include observations documenting that the North Atlantic is increasingly being freshened by melting glaciers, increased precipitation, and fresh water runoff making it substantially less salty over the past 40 years. This report suggests that, because of the potentially dire consequences, the risk of abrupt climate change, although uncertain and quite possibly small, should be elevated beyond a scientific debate to a U.S. national security concern.