Why should we believe Skeptical Science Basic Answers, TIA, rather than (for example) Watts Up With That? Skeptical Science is a well-known warmista site (and I acknowledge that WUWT may not be entirely impartial). So unless we trade cites/sites forever (which I decline to do) we have to make up our minds on other criteria.

Your quotation has at least one apparent inconsistency: "In fact, as temperature recording has improved in coverage, it's become apparent that ... global temperature trends were in fact relatively steady during the period prior to 1970." The implication is that improved temperature-recording post 1970 has showed that temperature-recordings pre 1970 were misleading. How does that work then? I'm not saying it's wrong, but it needs explanation at least.

Also, your quote concludes, "...we've reached a clear scientific consensus: 97% of working climate scientists agree with the view that human beings are causing global warming."

Ah, the ad populum logcal fallacy (and that apart from the fact that science is never "settled" - new findings tomorrow may completely overturn today's consensus). In today's zeitgeist, research funding is unavailable unless "AGW" appears in the application. What a surprise, then, that almost all "working climate scientists" support AGW, when all the others are no longer working because they can't get funding.

Governments like the implications of AGW: they can put up taxes, crying, "but it's green! green!" and if governments like anything more than controlling what we do it's spending our money. The cash they pour into climate research (but only for those projects which don't rock the AGW boat) makes any research money spent by big oil look like small change. Then there's all that money to be made by trading carbon credits...

I don't think that there's any evidence that climate change is significantly affected by human activity. I make this prediction: in 10 years from now AGW will be remembered only as a historical curiosity. I have made predictions on this site before: 11 years ago I predicted that the euro would fall apart within five years. I was wrong on the timescale, admittedly; but, given the situation in Greece, would anyone bet on the euro being around for another decade? (Sorry: I'm conflating two different hobby-horses.)