Your source is incorrect. The future will wonder why there were so many people unwilling or unable to examine the data and draw the same conclusion as the consensus of climate scientists, or at a minimum, recognize that these people's opinions are more informed than their own and defer to them, just as they will wonder why there were so many that did the same with vaccination rate versus death rate data. They'll wonder why we let this happen to them and their planet, and resent us for it.
Leftism fights against opposing views.
Why shouldn't it? But it does so democratically and civilly.
The American right is completely characterized by fighting opposing views, and there is nothing democratic or civil about it. The want to suppress the vote of those who would vote against their party. They want to suppress teaching racial history or gender identity issues in the public schools. They want to ban books. Anything they disagree with becomes PC or woke in an effort to inhibit such expression by mocking and demeaning it. The Republican party has only purpose when not in power, and that is to obstruct the Democratic president because he represents an opposing view. It attempted to obstruct the January 6th committee from forming and now does what it can to impede its purpose. It beset the recent Supreme Court nominee for no better reason than that they oppose everything from the left.
Liberalism has nothing to do with understanding climate science and its implications. People who oppose climate deniers do so not because they are liberal, but because they have developed a defense to indoctrination, critical thinking, which not only teaches one to look for a compelling argument before believing, but also teaches one how to do that - how to evaluate evidence properly to arrive at sound conclusions. Without that skill, one has to be able to decide who to trust. If one chooses to trust conservative media uncritically, he will be consistently lied to and he will accept the lies, because he has no defense against them, no test to decide if they are lies. But with those skills, one can say with confidence what is the case and who is wrong, and not be successfully lied to the propagandists.
Think about why you are promoting what you are here. Whose agenda are you serving? Not your own. You don't benefit at all by convincing others that you are correct. Whose agenda then? Somebody else's. That's pretty much always the case when being indoctrinated by anybody that doesn't know or love you. They also want you to hate liberals because liberals oppose them, and most conservatives comply uncritically. They want you to oppose taxing the wealthy. Do you think that that's because it benefits you? They want you to oppose Social Security, Medicare, and virtually any form of government support for ordinary people. Aren't you also one of those? Nothing they teach their uncritical audiences is for the benefit of the listeners.