In response to Madhav Khandekar and Tom Harris’s interview in PJ Media titled
which starts with
Subjected to a continual bombardment of catastrophism from climate activists, the public can be forgiven for assuming that recent extreme weather events, especially heat waves in North America, are unusual. Citizens would have little reason to suspect that most records for these phenomena were set many years ago.
But they were.
Madhav has provided us with the following summary:
” The current long, hot & dry summer in many parts of the US has prompted a number of climate scientists to sugget that this heat wave in the US and similar heat waves in Europe ( in 2010 & 2003) are linked to human-added CO2 over the past several years. I believe it is important to analyse past heat waves in the US and eslewhere before linking current heat wave to human-added CO2.
In the North American context, the decades of 1920s and 1930s ( known popularly as the Dust Bowl years) witnessed possibly the most anomalous climate of the 20th century, with recurring droughts and heat waves on the Great American Plains ( Canada as well as the US). The decade of the 1930s saw long and recurring droughts on the Canadian-America Prairies. There were locations (in Canada and US) where very little rain fell for the entire year or more in the 1930s! The highest temperature (at 45C) ever recorded in Canada was in a town in Saskatchewan in July 1937. Toronto, the largest city in Canada recorded its highest temperature ( at 41C ) on three days in July 1936. Several locations in US Midwest and in the Canadian Prairies recorded unusually high temperatures during the 1920s and 1930s. Meteorologists and climate scientists still do not fully understand why the North American climate was so anomalous! Human-added CO2 was certainly NOT a factor for such the long and recurring droughts (and associated heat waves) then!
The European heat waves of 2003 and 2010 have been now attributed to large-scale atmospheric patterns ( with a blocking development) and NOT to increasing concentrations of atmospheric CO2. In the monsoonal climate of India ( and south Asia) , a heat wave of few days to a week or longer duration often develops during the premonsoon months of April-June. Such heat waves ( with maximum temperatures at 43C and above) are associated with mid-tropospheric flow and possible delay in the arrival of monsoon rains. Heat waves in Australia are generally linked to ENSO phase producing less rainfall (reduced cloud cover) and dry soil condition. Heat waves in central Africa in particular, are associated with the movement of the ITCZ and associated rainfall patterns.
There is a definite need to understand the mechanics of heat waves in different parts of the world before linking recent heat waves in Europe and the US to human-added CO2.”