Climate scientists’ theories, flawed as they are, ignore some fundamental data.
IN THE theory of man-made climate change, two-thirds of the predicted warming comes from changes in humidity and clouds, and only one-third comes directly from the extra carbon dioxide (CO2) and other greenhouse gases.
The theory assumes humidity and clouds amplify the warming directly due to CO2 by a factor of three: extra CO2 warms the ocean surface, causing more evaporation and extra humidity. Water vapour, or humidity, is the main greenhouse gas, so this causes even more surface warming.
Not many people know that. It is the most important feature of the debate, and goes a long way to explaining why warmists and sceptics both insist they are right.
The warmists are correct that CO2 is a greenhouse gas and it causes warming, that CO2 levels have been rising, and that it has been warming.
Serious sceptics agree with all that, but point out that it does not prove that something else isn’t causing most of the warming. By way of illustration, if the main cause of warming was actually Venusians with ray guns, then all those things would still be true.
The sceptic’s main suspect is the sun. While the sun’s radiation is roughly constant, its magnetic field varies considerably. This field shields the earth from cosmic rays that, according to recent experiments at the world’s premier atom smasher CERN, might seed clouds. Clouds cool the planet, so if the sun’s magnetic field wanes, then it might get cooler here on earth.
We scientists can calculate how much warming results directly from an increase in CO2 levels. We know how much CO2 levels and temperature have risen since pre-industrial times, but the warming directly due to CO2 is only a third of the observed warming. The theory assumes no other major influence on temperature changed, so the effect of the CO2 must have been amplified threefold, presumably by changes in the atmosphere due to humidity and clouds.
There is no observational evidence for this amplification, but it is nonetheless built into all the models. Sceptics point out that if the extra humidity simply forms extra clouds, then there would be no amplification.
If the CO2 theory of global warming is right, the climate models should predict the climate fairly well. If the CO2 theory is wrong, because there is another, larger driver of the temperature, then the climate models will perform indifferently.
According to the latest data from mankind’s best and latest instruments, from impeccable sources, the climate models are doing poorly.