Indeed, there's no gun to our heads preventing us voting for taking serious action on climate change. There doesn't need to be.
Imagine I'm a voter in, say, the US or the UK. There is no major party I can vote for that will, if elected, take serious action on climate change. In both nations there is a Green Party which probably would, but it has a firmly established track record of getting approximately zero votes; the only way in which voting Green has ever had any visible impact on US or UK policy is that a bunch of people voting for Ralph Nader in the 2000 US presidential election is part of why we had President Bush instead of President Gore, which is probably not an encouraging precedent to most potential Green voters.
And, of course, voting Green also means voting for all their other policies. Which doesn't matter if you regard climate change as the only important issue, but since you probably don't, you might find them unacceptable on other grounds; and since lots of other voters definitely don't, lots of them are going to be voting not-Green even if they care a lot about climate change ... which means that, once again, the Greens are not actually going to win, and the only real effect of voting for them is to give you less influence on which actually-electable candidate wins instead.
So no, in practice we don't have the option of voting for taking serious action on climate change. We have the option of voting for a big package of things, one of which happens to be serious action on climate change, in the knowledge that (even if a sizeable majority of voters wants serious action on climate change) voting for that package won't actually result in a government that will try to implement it.
It may be that those of us who care about climate change should be voting Green even though it predictably won't help in the near future, in order to "send a message" that might change the political landscape in future elections. Or that we should be putting pressure on the actually-electable parties to change their policies, or starting new parties, or something. But none of that means that we have a realistic way of getting action on climate change just by voting for it.