Global climate change doesn't have a definable and agreeable source and/or event that can be confined to definite set of parameters. The cause and effect chain

Global climate change doesn't have a definable and agreeable source and/or event that can be confined to definite set of parameters. The cause and effect chain is nebulous in comparison. But damage caused by radiation is well known, definable criteria which is well studied as part of health studies. What would be more comparable would be studies of heart disease for example based on consumption of certain foods. We readily accept such studies as advice on what is health, what is not, and also what drugs work and which do not. The principle is the same.