Why Blame Carbon Dioxide?
Can there be evidence that carbon dioxide causes global warming? We can see that there is less arctic ice and shrinking of glaciers but the explanation could conceivably be that snowfall in their catchments has reduced. Even if there is warming, attributing these effects to it cannot be tested because causality is invisible and cannot be identified with certainty. Attributing the effect to carbon dioxide cannot be observed or tested directly. It’s too important to guess.
Scientists often establish causality by testing with a physical model. If there warming was observed in many tests and few results were without warming, nor many with cooling, then by the principle of induction the warming could be associated with carbon dioxide, under those conditions. No physical model can be large enough to approximate the Earth’s atmosphere and oceans. Models could possibly corroborate that carbon dioxide does cause warming (I haven’t heard of any such tests). Even so, models could add their logic to the theory but can never verify it absolutely.
People who use the reduced ice effects as evidence can be deceived by an a priori result, because melting was assumed to cause the reduction in ice observed, a circular argument and false.
Increased carbon dioxide in the atmosphere is not a smoking gun. Warming of the oceans is causing them to release some of their dissolved store of carbon dioxide. Warming has caused the carbon dioxide increase, not vice versa.
Attributing the cause of ice reduction to carbon dioxide with reasonable confidence requires that possible alternative causes are eliminated. The effect on ice of co-products of fossil fuel combustion, heat and water vapour, could also be to reduce it. Alternatively, Earth warming by the Sun has variable solar processes and Earth orbits that could cause warming and melting.
Other science theories, such as gravity, evolution and relativity, also have invisible causality and were adopted before their science was fully understood. Philosophies of science were modified to accommodate these theories. Carbon dioxide’s culpability could be accepted without evidence, provided it is logical, if it is not contradicted and if other explanations are not credible.
I have mentioned several alternative theories of ice reduction. William of Occam wanted preference to be given to the simplest theory. Thermal emissions explain warming more simply than does carbon dioxide. The significance of carbon dioxide needs to be reconsidered.
My coming novel Animal Farm 2 is a sequel to George Orwell’s Animal Farm and satirizes totalitarianism, animal liberation and climate change. martinknox.com