Many scales of climate change are in fact natural, from the slow tectonic scale, to the fast changes embedded within glacial and interglacial times, to the even more dramatic changes that characterize a switch from glacial to interglacial. So why worry about global warming, which is just one more scale of climate change? The problem is that global warming is essentially off the scale of normal in two ways: the rate at which this climate change is taking place, and how different the "new" climate is compared to what came before.
We wield an enormous influence over the world through how we choose to vote and what we choose to buy. Again, it's the power of numbers. If voters hold their leaders responsible for doing something about global warming, it will get done. If most people refuse to buy products from companies that, for example, wrap products in more plastic than necessary, pretty soon the plastic wrapping will stop.