AGW may well be gubbins, but climate change isn't. It's always gone on, and can be very sudden (with an equally sudden halt).
The thing to remember is that there is no steady state. In any given year, decade, century or millennium there are fluctuations on the micro (daily/weekly/monthly/annual) through to the macro (ages and aeons) level, and there are a great many factors in play (relative distance from the sun, the solar cycle itself, the chemical composition of the atmosphere at any given time, to name but a few). Naturally, we think that there is some kind of steady state because our personal experiences are so limited. Paradoxically, we also argue that it is warmer now than it used to be because, again, our experience is skewed (I've yet to read a proper study into the short, middle and longer term effects of all those nuclear tests, for example, even though they must have thrown all kinds of stuff into the atmosphere that made winters colder and longer on average from about 1945 through to the 1970s, and then of course there were the effects from several volcanic eruptions to factor in).
Another problem comes down to our apparent willingness to separate ourselves from the planet in some ways. It's all 'We're doing this' and 'We are not!'...when the truth is, we are having some kind of effect simply because we are here. It's not 'Planet System' and 'Human System' in conflict but a single system of which we are an integral (as well as an accidental and ultimately unnecessary) part.
So, we might not be the sole or even the largest cause of climate change - it'd happen no matter what - but we are having an influence that could be accelerating the natural process, or diverting it along unnatural lines (so instead of the northern polar ice cap shifting to cover, say, a large part of Russia, it shifts more towards Scandinavia and Britain - with the rest of northern Europe becoming markedly colder while a chunk of Canada and the northern states of the US warm up. Or vice versa).
And don't forget, no steady state also means that we are still, technically, emerging from the last Great Ice Age, so it'll get incrementally warmer until Whatever happens and we start sliding into the next one.
In the meantime, do what you can to stop habitat destruction in the Amazon and invasive livestock farming in the Serengeti, protest shark-finning and tiger trapping, and avoid products made with or from palm oil (habitat loss is driving the Sumatran tiger to extinction), as well as attempting to disengage from the consumer society. It'll have to end anyway when the world's resources run out (we're using the resources of 3 Earths despite having ~55% remaining of the one we're on: in other words, our economic model uses at least six times what the planet can afford to sustain - and that's without increased demand from elsewhere and the demand for ever-increasing economic growth).
Better to start the social and economic shifts now, when we can manage it properly, than wait until there's no option and the crap hits the fan.