Paul Homewood has a post today: Who Is Lying? John Holdren, Jennifer Francis, Or NOAA?
The issue revolves around claims of global warming changing the jet stream, resulting in extreme weather, including colder winters in the US. That’s a neat trick: Getting global warming to produce cold weather.
Lying presumes they know the truth and speak falsely. This is more a case of saying what they believe but being wrong. (“Love of Theory is the Root of all Evil” –William Briggs)
Seasoned meteorologist Judah Cohen of AER sees it differently.
My colleagues, at AER and at selected universities, and I have found a robust relationship between two October Eurasian snow indices and the large-scale winter hemispheric circulation pattern known as the North Atlantic or Arctic Oscillation pattern (N/AO).
The N/AO is more highly correlated with or explains the highest variance of winter temperatures in eastern North America, Europe and East Asia than any other single or combination of atmospheric or coupled ocean-atmosphere patterns that we know of. Therefore, if we can predict the winter N/AO (whether it will be negative or positive) that provides the best chance for a successful winter temperature forecast in North America but certainly does not guarantee it.
He goes on to say that precipitation is the key, not air temperatures, and ENSO is a driving force:
As long as I have been a seasonal forecaster, I have always considered El Nino/Southern Oscillation (ENSO) as a better predictor of precipitation than temperature across the Eastern US. I think this is supported by the observational or statistical analysis as well as the skill or accuracy of the climate models.
There have been recent modeling studies that demonstrate that El Nino modulates the strength and position of the Aleutian Low that then favors stratospheric warmings and subsequently a negative winter N/AO that are consistent with our own research on the relationship between snow cover and stratospheric warmings. So the influence of ENSO on winter temperatures in the Mid-Atlantic and the Northeast may be greater than I acknowledge or that is represented in our seasonal forecast model.
As Cohen’s diagram shows, there is an effect from warming, but in the stratosphere. Global warming theory claims CO2 causes warming in the troposphere and cooling in the stratosphere. So whatever is going on, it is not due to CO2.
Cohen’s interview with the Washington Post.