The Azimuth Project
Abrupt climate change


At various times in the Earth’s history, the climate has suddenly shifted from one state to another; this is called abrupt climate change. As we perturb the climate via global warming, we must consider the possibility that we will push it past a [tipping point], causing an abrupt change of some sort. As the climatologist Wallace Broecker wrote:

…we’re entering dangerous territory and provoking an ornery beast. Our climate system has proven that it can do very strange things.

The study of climate history offers us examples of what might happen. For example, the Younger Dryas is a cold period in Europe that lasted roughly from 10,800 BC to 9,500 BC. As you can see, it began abruptly and seems to have ended even more abruptly:

Greenland temperatures over the last 18,000 years

Other examples include Dansgaard-Oeschger events, Heinrich events and the Paleocene-Eocene thermal maximum?.



The quote from Wallace Broecker is from:

  • Wallace S. Broecker, [Will our ride into the greenhouse future be a smooth one?] GSA Today 7 (May 1997), 1-7.

The discussion of the Younger Dryas in the above article is somewhat outdated, but still interesting.

The temperature chart at the top of the page is based on Greenland ice cores. It is taken from:

  • Richard B. Alley, The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change, and our Future, Princeton U. Press, Princeton, 2002.

category: climate