The Union of Concerned Scientists’ Kendall Science Fellow and Scientist Roberto Mera discusses how today’s changing climate and recent record-setting wildfires this year in the Pacific Northwest is compelling scientists to search for ways to determine the cause behind the observed trends.
The Pacific Northwest has experienced a statistically significant warming trend of 0.7°C (1.3°F) in an annual mean temperature from 1901-2012, as indicated in a recent study by Abatzoglou and co-authors in the Journal of Climate. This trend has been attributed to heat trapping emissions as the leading contributor to long-term warming.
This past week we saw a highly provocative alternative to Abatzoglou et al’s findings: the main cause of the century-long warming trend is due to natural changes in atmospheric circulation over the northeast Pacific, according to a new study by Johnstone and Mantua in the PNAS journal. The publication by Johnstone and Mantua has received a great deal of attention in the media, including an article in the New York Times. But how could such different conclusions be reached?
Read more on the Union of Concerned Scientists blog: http://blog.ucsusa.org/warming-trends-in-the-pacific-northwest-are-not-due-to-natural-variability-668