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.
An excellent example is Brexit. The Brexit referendum existed solely because of UKIP and UKIP have only ever won 2 parliamentary seats. And those were both for sitting MPs that had defected.
However, UKIP did get 4-odd million votes, plenty of local councillors, MEPs etc. In other words, they clearly had a lot of support for their flagship policies and that caused the main parties, that had UKIP voters in their constituencies, to take notice. Unfortunately.
This has also, to a lesser extent, been the case with green issues. The Greens increased their vote from the 80's onwards and the main parties started to adopt green policies accordingly.
So, in the UK at least, there are well worn paths to get policies, like climate change action, to the top of the heap.
I'd argue that there are a few reasons why they're not top of the heap today:
1) Other things are deemed more important. Clearly Brexit is one. Whether you agree that it should be more important, or not, it's fairly undeniable that it's true.
2) The folk that have expressed most interest in green issues have tended to not be very engaged in formal politics. <30s predominantly. That changed somewhat in the 2017 election primarily because of Corbyn (though Greens did particularly badly). So it may be that green issues become more important as a byproduct of other changes.
3) There's a strong argument that UKIP's popularity was, in large part, due to Nigel Farage. He may well be a cock but he's a cock that was on TV a lot reinforcing his message. I mean, I like Sian Berry (no idea who the other bloke is) but she's no Nigel Farage.
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.