The trouble with OpenID is it's still one identity that you're carting around, allowing yourself to be tracked across multiple sites.

A better solution is just to use a password manager (KeepassX, Last Pass, etc.) which lets you manage your own multiple identities in a secure way. This gives you the convenience of a single sign-on with the security of a distinct identity for every site where you want it.

> No one has proven a link between "greenhouse gas" emissions and any periods of climatic change.

This is true, it isn't proven. But, in the last 650,000 years, there is a strong correlation between greenhouse gases and temperature. And, the process by which greenhouse gases work to increase temperature is understood. Given this evidence, how much more "proof" do you need? Do you have an alternative theory that describes the evidence more accurately and simply?

Or perhaps you still think epicycles are a valid theory... We can never be sure, after all.