Potsdam Institute’s Stefan Rahmsdorf trashes the concept of mean global temperature since it hasn’t worked for warmists in 17 years.
…Climate change caused by greenhouse-gas emissions from fossil-fuel burning does not bring a uniform global warming. In the Arctic, the warming is amplified by the loss of snow and ice. This in turn reduces the temperature difference between the Arctic and, for example, Europe. Yet temperature differences are a main driver of air flow, thereby influencing the planetary waves. Additionally, continents generally warm and cool more readily than the oceans.
These two factors are crucial for the mechanism now detected. They result in a changing pattern of the mid-latitude air flow, so that for extended periods the slow waves get trapped. The irregular surface temperature patterns disturb the global air flow. This analysis is based on equations that our team of scientists developed, mathematically describing the wave motions in the extra-tropical atmosphere. The conclusions drawn from the equations were tested using standard daily weather data from the US National Centers for Environmental Prediction (NCEP).
During recent periods in which several major weather extremes occurred, the trapping and strong amplification of particular waves – like “wave seven” (which has seven troughs and crests spanning the globe) – was observed. The data show an increase in the occurrence of these specific atmospheric patterns.
This analysis helps to explain the increasing number of unprecedented weather extremes. It complements previous research that already showed that climate change strongly increases the number of heat records around the world, but which could not explain why previous records were broken by such stunning margins. The findings should significantly advance the understanding of weather extremes and their relation to man-made climate change…