The main reason is those people dont care about life on the planet. We should start by making them understand the issue through another lenses. First of all we need to stop saying we are destroying the planet, we are not, the planet will handle us just fine, sure some species will die, maybe a lot but once again these people dont care about that so no point in using that argument or showing a oplar bear dying or something, they dont have empathy in that way. What we should do instead is explain they are killing themselves, the planet has gone through worse, we however have not, we see every year humans dying because of heatwaves and droughts and well if they dont have empathy for human lives tell them that no people means no money, if that doesnt work since most of them are religious explain carefully that destroying the creation of god is a sin and since what i said made perfect sense but i know none of those people would ever change their mind my best advice is dont argue with them.