Western Europe is warming much faster than expected

Abstract

Abstract. The warming trend of the last decades is now so strong that it is discernible in local temperature observations. This opens the possibility to compare the trend to the warming predicted by comprehensive climate models (GCMs), which up to now could not be verified directly to observations on a local scale, because the signal-to-noise ratio was too low. The observed temperature trend in western Europe over the last decades appears much stronger than simulated by state-of-the-art GCMs. The difference is very unlikely due to random fluctuations, either in fast weather processes or in decadal climate fluctuations. In winter and spring, changes in atmospheric circulation are important; in spring and summer changes in soil moisture and cloud cover. A misrepresentation of the North Atlantic Current affects trends along the coast. Many of these processes continue to affect trends in projections for the 21st century. This implies that climate predictions for western Europe probably underestimate the effects of anthropogenic climate change.

Understanding the rapid summer warming and changes in temperature extremes since the mid-1990s over Western Europe

“…1a). The change in SAT during the recent 16 years (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011) relative to the early period 1964-1993 ranges from 0.93 to 1.10 °C from four data sets, consistent with previous studies (Ruckstuhl et al 2008;Philipona et al 2009;van Oldenborgh et al 2009). The rapid summer mean warming over Western Europe was also accompanied by changes in temperature extremes.…”

“…Understanding the nature and drivers of this variability is an essential step in developing robust climate predictions and risk assessments. In the last few decades, Europe has warmed not only faster than the global average, but also faster than expected from anthropogenic greenhouse gas increases (Ruckstuhl et al 2008;Philipona et al 2009;van Oldenborgh et al 2009). With the warming, Europe experienced record-breaking heat waves and extreme temperatures that imposed disastrous impacts on individuals, and society (Stott et al 2004;Fischer and Schär 2010;Barriopedro et al 2011;Christidis et al 2011Christidis et al , 2012Hegerl et al 2011;Rahmstorf and Coumou 2011;Hoerling et al 2012;Schubert et al Abstract Analysis of observations indicates that there was a rapid increase in summer (June-August) mean surface air temperature (SAT) since the mid-1990s over Western Europe.…”

Global changes in extreme events: regional and seasonal dimension

“…The median is always in between these tendencies. These seasonal warming patterns agree well with results from other studies, which attribute them to snow and soil moisture effects (Seneviratne et al 2006;Diffenbaugh et al 2007;van Oldenborgh et al 2009). A stronger warming of the hot tails of temperature distributions with decreasing soil moisture content is also a feature found in observations from Southeastern Europe .…”

North American extreme temperature events and related large scale meteorological patterns: a review of statistical methods, dynamics, modeling, and trends

“…The additional possibility of biases and changes in LSMPs affecting extreme temperatures must be considered in light of these and other mechanisms. For example, van Oldenborgh et al (2009) found that changes in the large-scale circulation, including a shift towards a more westerly circulation and the North Atlantic current need to be better simulated especially in winter and spring for more realistic simulations of warming over Western Europe in recent decades. Gershunov and Guirguis (2012) noted that three out of four GCMs analyzed did not adequately capture the synoptic causes of California heat waves.…”