The problem with climate “science” is that the data – which are telling us to relax – fly in the face of the strong tendency of its advocates to bully us into a panic.
We are asked to drop all common sense and to accept that CO2 – a monumentally insignificant fraction of the air – is the control knob of the climate.
I consider climate science’s recommendations to be less worthy of acceptance in comparison with those of biotechnology for five main reasons.
First, established physics theories are precise and have a single set of equations but we have over a hundred different climate models. One can understand different parametric estimates for sensitivity analysis but when hundreds of different sets of equations purport to forecast the future we know that the science is not settled.
Second, the average predictions of climate models have grossly exceeded observed temperatures. This has been found not only in James Hansen’s model but in charts in the IPCC’s own 2013 report. A paper by Fyfe, Gillett and Zwiers in Nature in 2013 showed how badly climate models have performed. John Christy’s subsequent comparison of model predictions with satellite temperature measurements has come to the same conclusion. The Economist magazine said it well in 2013 that “If climate scientists were credit-rating agencies, climate sensitivity would be on negative watch”.
In addition, Roy Spencer’s analysis of ocean warming, using data in IPCC’s own report shows much lower climate sensitivity than even in the moderate IPCC scenarios. Recently he mentioned a 2018 peer-reviewed paper that re-confirms this. And I don’t even want to start off on the tens of false alarms that have splattered newspapers over the past century.
Third, the suggested strong correlation between CO2 and temperature simply does not exist. I looked at IPCC’s first report and found no correlation at all: (a) there were extensive variations in the climate over the past few thousand years despite CO2 remaining pretty much constant, and (b) when CO2 actually started increasing rapidly from 1950, the temperature plummeted for three decades. At that time, in the 1970s, climate scientists scared us about an impending Ice Age.
Many independent and bigger underlying natural causes than CO2 are at work including forces that pulled us out of the Little Ice Age (c.1400 to c.1800). One of these causes relates to the Atlantic multidecadal ocean oscillation that Judith Curry and other scientists have studied. Her study of the oscillation’s effect on Arctic ice is illuminating.
Such forces add sinusoidal and non-linear overlays to the trend of recovery of temperatures from the Little Ice Age and explain not only the significant warming of the first part of the 20th century (which took place without any CO2 emissions) but the subsequent cooling till the late 1980s and the small subsequent warming surge followed by a pause over the first twenty years of this century.
In fact, the increase in temperatures in the past thirty years is principally no different to the increase of the first half of the 20th century except that it comes on top of a higher base because of the longer-term trend since 1800. Yes, the climate is changing and yes, the greenhouse gas effect is rock-solid science but the observed sensitivity of the climate to increases in CO2 is very low.
Fourth, I want to briefly touch upon data quality since no science can succeed without high quality data. The reader will notice I have deliberately cited the first IPCC report’s charts, not its recent reports informed by a controversial (and arguably defective) study. Geologists who have studied this issue tell us that there definitely was medieval warming and a Little Ice Age – there is too much circumstantial evidence to “disappear” them.
It is concerning that IPCC has tried to erase both these well-established periods. More problematically, we see regular reports in newspapers that physically measured temperatures of the past are being changed to fit the “panic” claims. The book “Evidence-Based Climate Science”, edited by highly respected scientist Don Easterbrook and published by Elsevier, contains a chart at page 130 that confirms these suspicions.
I have come to the view that we can trust only four pieces of data: temperature measurements by satellites – particularly of the troposphere, sea level measurements (which are getting better due to satellites), ocean temperature measurements and counts of extreme events and their intensity over the past 100 years. All four of these measures provide strong assurance that the planet’s sensitivity to CO2 is extremely low.