Where is the evidence for catastrophic climate change from human action?

A piece by Dr Chris de Freitas is here.

Excerpt:

The robustness or otherwise of the science underpinning the role of greenhouse gases in the atmosphere is the key to assessing the risk from human induced climate change issue. But seldom if ever are the uncertainties of the science discussed.

Seldom if ever is the question asked: Where is the evidence for catastrophic climate change from human action?

Rather than search for the evidence, groups like Greenpeace defer to authorities, such as the Intergovernmental Panel on Climate Change (IPCC), a political entity which appears to have a monopoly on wisdom in global warming matters.

Rather than debate the issues, they attack those who disagree, using defamatory labels. Yet the opposite of scepticism is gullibility.

The fanatical name calling and personal attacks expose the strong ideological elements that drive global warming alarmist thinking. It's as if the depth of passion is overcompensation for doubt and uncertainty.

Why else would environmentalists squander so much effort trying to discredit individuals and organisations who disagree?

Few scientists are willing to put their head above the parapet, for a variety of reasons, not the least of which is that, to paraphrase Voltaire, it is dangerous to be right when the authorities are wrong.