"Climategate" has been vastly exaggerated.
I said before on another thread that, in any other field of science, the apparent discrepancies, changes to modelling, new numbers, etc, would be seen as progress. Climate Science is perhaps unique in being so susceptible to political interpretation, and that has apparently given licence to its being used and abused appallingly by people who simply don't have the faintest experience in how to separate truth from fiction, "good" science from "bad" (here, I stress, I mean the methodology, rather than the conclusions -- it is clearly possible ab initio for "good science" to reach many different 'answers').
Take, for example, 10CS's point that the Sun is the only influence on the planet's climate. This is simply wrong: the Sun is clearly a major influence on our climate, there's no doubt about that, but what also matters is the atmosphere and its contents. Compare the climates of Venus and Earth, for example: unsurprisingly, Venus is hotter, but that higher temperature is down far more to the different atmospheres than it is to the distance to the Sun*. Likewise, Mars is far colder than you'd expect from its distance to the Sun, relative to Earth at least.
Or, to be even more obvious, compare the Climates of Earth and the Moon. On its own that destroys any suggestion that the atmosphere and what makes it up is somehow irrelevant, and it's clear that anyone who suggests that the Sun is the *only* influence has never really thought about the problem beyond what's needed to sound authoritative and dogmatic.
The Sun, then, is far from the only contributor, even though it's obviously important. What makes up the atmosphere matters too, in quantifiable ways. In particular, the greenhouse effect is uncontroversial; the fact that human activity is increasing greenhouse gas concentrations is also uncontroversial; and the fact that a change in the latter may affect the former is also pretty clear, even if the response is highly non-linear in ways we still have yet to understand.
Long story short: predictions about the future path of Climate Change are always subject to corrections and updates, and sadly those have been given way more attention than they deserved -- but the conclusion that human activity is having, and will continue to have, a measurable influence on the planet's climate is a very simply chain of common-sense links, now supported by incredibly robust science. Only those who have a transparent political motive can seriously argue against it, and the number of those is rapidly, and mercifully, diminishing.