Explaining Extreme Events of 2014

Explaining Extreme Events of 2014 from a Climate Perspective Report Cover

Human activities, such as greenhouse gas emissions and land use, influenced specific extreme weather and climate events in 2014, including tropical cyclones in the central Pacific, heavy rainfall in Europe, drought in East Africa, and stifling heat waves in Australia, Asia, and South America, according to a new report released today. The report, Explaining Extreme Events of 2014 from a Climate Perspective published by the Bulletin of the American Meteorological Society, addresses the natural and human causes of individual extreme events from around the world, including Antarctica, in 2014. NOAA scientists served as four of the five lead editors on the report.

“For the past four years, this report has shown that human activities are influencing specific extreme weather and climate events around the world,” said Thomas R. Karl, LHD, director of NOAA’s National Centers for Environmental Information. “In the 79 papers that have been published through the annual report over the past four years, over half of these papers show a linkage to human-caused climate change.”

When a climate change influence is not found it could mean two things. First, that climate change has not had any appreciable impact on an event. Or, it could also mean that the human influence cannot be conclusively identified with the scientific tools available today.

In this year’s report, 32 groups of scientists from around the world investigate 28 individual extreme events in 2014 and break out various factors that led to the extreme events, including the degree to which natural variability and human-induced climate change played a role.

A number of this year’s studies indicate that human-caused climate change greatly increased the likelihood and intensity for extreme heat waves in 2014 over various regions. For other types of extreme events, such as droughts, heavy rains, and winter storms, a climate change influence was found in some instances and not in others. The report this year added analysis on new types of events including wildfires and Antarctic sea ice extent, and it looked at how land use patterns may influence the impacts and severity of such events. In addition, several papers in this year’s report have integrated other human influences besides climate change. For example, a study of a flood in Canada showed that human land use changes, as well as global warming led to an increase in severity and likelihood in the flood.

“Understanding our influence on specific extreme weather events is groundbreaking science that will help us adapt to climate change,” said Stephanie C. Herring, PhD, lead editor for the report at NOAA’s National Centers for Environmental Information. “As the field of climate attribution science grows, resource managers, the insurance industry, and many others can use the information more effectively for improved decision making and to help communities better prepare for future extreme events.”

The report was edited by Herring, along with Martin P. Hoerling, NOAA’s Earth System Research Laboratory; Thomas Peterson and James Kossin, both from NOAA’s National Centers for Environmental Information; and Peter A. Stott, UK Met Office Hadley Centre. The report includes a global authorship from more than 20 countries. View the full report online.

For more information, see the NOAA Press Release and view the slides for the media briefing on the report.