From the viewpoint of a skeptical former Sierra Club activist and USEPA senior analyst
Aug. 19, 2016 – Alan Carlin
Climate alarmism is probably the greatest hoax/scam in world history. The main evidence for catastrophic anthropogenic global warming (CAGW), the principal alleged adverse effect of human emissions of carbon dioxide (CO2), is climate models built by CAGW supporters in a field where models with real predictive power do not exist and cannot be built with any demonstrable accuracy beyond a week or two because climate and weather are coupled non-linear chaotic systems. Without the models, the whole hoax/scam collapses. Even the Intergovernmental Panel on Climate Change (IPCC) has stated (see Section 18.104.22.168 of the 2001 IPCC Report):
In climate research and modeling, we should recognize that we are dealing with a coupled non-linear chaotic system, and therefore that long-term prediction of future climate states is not possible.
Climate Modelers Knew or Should Have Known the Inherent Limitations of Climate Models
The hoax/scam appears to rest on the authors’ assumption that most people will not realize these inherent limitations of global climate models. Since the model authors all work in the field, they either knew this or should have known these limitations (unless they delude themselves, of course). The authors of the models have a self-interest in supporting CAGW since government grants almost always go only to supporters. This self-interest is what makes the hoax into a scam. If true climate believers understood that longer term projections cannot be made on the basis of these models, they would hopefully dismiss the whole hoax/scam for what it is.