A NOAA-led report released September 5 by the Bulletin of the American Meteorology Society – entitled “Explaining Extreme Events of 2012 from a Climate Perspective” – casts a pall on the effects of human influences on extreme weather and climate events.
Three of four lead editors on the report hailed from NOAA, and overall, 18 distinct research teams from across the globe offered their expert opinions as to the causes of 12 extreme events that transpired in the Arctic and on five continents.
The Associated Press reports that of the 12 wild weather events studied, researchers linked approximately half of the events to man-made climate change.
The report suggests that the effects of natural fluctuations in weather and climate played a key role in the development and intensity of many of the 2012 extreme events. However, in several events, the study found convincing evidence that manmade contributions to climate change was a secondary factor adding to the extreme weather event.
“This report adds to a growing ability of climate science to untangle the complexities of understanding natural and human-induced factors contributing to specific extreme weather and climate events,” said Thomas R. Karl, LHD, director of the National Climate Data Center. “Nonetheless, determining the causes of extreme events remains challenging.”
In addition to investigating the factors that caused the extreme events, analyses of four of the events – warm temperatures in the United State, record-low Arctic sea ice levels, heavy rain in northern Europe and eastern Australia – allowed the scientists to compare and contrast the strengths and weaknesses of their various methods of analysis. In spite of their diverse strategies, there was considerable agreement between the assessments of the same events.
“Scientists around the world assessed a wide variety of potential contributing factors to these major extreme events that, in many cases, had large impacts on society,” said Thomas Peterson, PhD, principal scientist at NCDC and one of the lead editors of the report. “Understanding the range of influences on extreme events helps us to better understand why extremes are changing.”
In a Q & A session on Climate.gov, Peterson answered a number of questions posed by interviewer Rebecca Lindsey in a session entitled, “Global warming, or just the weather?”
Question: “Is knowing that a type of extreme event will become more frequent the same thing as saying those events will become more predictable?”
Answer: “Not necessarily. In some circles, they lump extreme event attribution and prediction together as one ‘grand challenge’ because solving one part of it could help with the other part. If you could better predict extreme events, you would have a better understanding of the factors that influence them, and vice versa. If you understand the attribution of an extreme event, then—maybe—you could better predict those events it the future.”
What do you think of the report’s findings? Share your thoughts in the comments section.