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 in 2014, including Antarctica. NOAA scientists served as three of the five lead editors on the report.
For each of the past four years, this report has demonstrated that individual events, like temperature extremes, have often been shown to be linked to additional atmospheric greenhouse gases caused by human activities, while other extremes, such as those that are precipitation related, are less likely to be convincingly linked to human activities," said Thomas R. Karl, L.H.D., director of NOAA's National Centers for Environmental Information. "As the science of event attribution continues to advance, so too will our ability to detect and distinguish the effects of long-term climate change and natural variability on individual extreme events. Until this is fully realized, communities would be well-served to look beyond the range of past extreme events to guide future resiliency efforts."
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. When human influence for an event cannot be conclusively identified with the scientific tools available today, this means that if there is a human contribution, it cannot be distinguished from natural climate variability.