Noah S. Diffenbaugh, Deepti Singh, Justin S. Mankin, Daniel E. Horton, Daniel L. Swain, Danielle Touma, Allison Charland, Yunjie Liu, Matz Haugen, Michael Tsiang, Bala Rajaratnam

Proceedings of the National Academy of Sciences

Published date April 24, 2017

Quantifying the influence of global warming on unprecedented extreme climate events

The world is not quite at the point where every hot temperature record has a human fingerprint, but it's getting close to that.

Noah Diffenbaugh, lead author and Stanford University climate scientist

This is a step forward in that it allows general statements about what fraction of events of the given types selected have a statistically significant

Adam Sobel, a Columbia University climate scientist  who wasn't part of the study

  • Analyzes weather stations worldwide and calculates the global trend in warming that contributed to the record for hottest day of the year in at least 82% of the records for hottest day over the 1961-2010 period, including contributing at least 30% of the magnitude over large areas of Europe and eastern Asia, and increasing the probability by at least a factor of 2.5 over most of Europe and parts of western North America and eastern Asia.
  • Spots climate change's influence 57 percent of the time in records for lowest rainfall in a year and 41 percent of the time in records for most rain in a 5-day period
  • Formally identifies the fingerprint of anthropogenic warming in the observed trend of increasing heat extremes over the western U.S.
  • Applies four attribution metrics to four climate variables at each available point on a global grid
  • Results suggest that scientifically durable operational attribution is possible but they also highlight the importance of carefully diagnosing and testing the physical causes of individual events