As much as i would like to, i can't agree that gun-nuts should be lumped together in the same category as climate change deniers.
Australia had a mass shooting, banned guns, and then had no more mass shootings. But with a population of only ~30 million (i haven't looke this up, so it is from memory) Australia is like one american state.
You take new york city and place all kinds of fire arms bans (because the city has a high gun-crime rate) and the crime rate either drops, remains stable, or increases, but regardless you still end up with guns available just across the state border/cury boundary. So New Yorkers can still buy (hand guns, assault rifles, whatever else you can politically ban...) various weapons.
Politically it is impossible to ban guns actoss the US, and that leaves New York with a high gun-crime rate - despite implementing tighter gun control than everywere else.
Proof therefore that the gun control in NYC didn't work. Now maybe the crime rate came down, maybe there were less mass shootings, and maybe New Yorkers are better off, BUT unlike climate change, the facts show that cities in the US with the tigthest gun controls continue to have the worst crime rates.
So it does take a certain kind of political propoganda/brain-washing to belief this perspective. BUT, we're not talking about solid scientific facts. If you choose to live in a country of state with a certain culture of gun use, that is your choice, and if your politics supports that culture, then you should be happy.
If you don't like that gun crime rate, then that is a political issue which you may struggle with. Fine, struggle away, you are not wrong for holding different political views to mine. (Which, to be clear, are i prefer to live in a country where the majority of the police are not armed, because virtually nobody has access to firearms, i feel much safer)
Now climate change is based on fact. You can prefer to live in a society with guns, and your feelings (ie that you are safer with guns) are true, even if they are different from my feelings (ie that i am safer without guns) you are entitled to your own feelings. You are not entitled to your own facts.
You can disagree about what the appropriate responce to climate change is. You can even think that the vast majority of climate scientists are wrong. But that doesn't change the facts.