Slap them in the face. If they complain, tell them the pain is real but human activity didn’t contribute to it.

Just show them that one xkcd about how abrupt the current warming is and how nicely it lines up with industrialization. The comparison between the natural slow shifts in global climate vs. what's been happening the last century or so is the clearest counter to "but the climate has always been changing".

The other times that things have changed in comparable timescales, it's been caused by supervolcanoes or other such calamities.

Edit: Oh yeah one caveat: The xkcd is ten years old and we're now actually already around +1.5°C.

Nothing. You can’t logic someone out of a position they didn’t use logic to get to in the first place. There’s way more unmotivated and un-mobilized people out there that believe in human caused climate change that are more worth your time and energy.

If your house is too warm and you're running 20 electric heaters but for some reason think it's something else causing the heat, it'd still pay to turn off some of those heaters to compensate for the external cause since you actually have control over the heaters.

If you really think that anything you say will have any impact on them then maybe it doesn't matter what the cause is as long as you can get them onboard with the solution. The two are inextricably linked so if they're really adamant about this you'll probably not be successful in this endeavour but it's worth a try if you have some faith in them. If they think it's all long term cyclical solar patterns or some other non anthropogenic cause it might be worth pointing out that it's still happening and causing consequences. The trouble will be not implying too heavily as I have in my heaters example, that the solution is obviously linked to the cause, even if it is. Otherwise they will not believe you have common ground.

This seems to have worked with my boomer mom: "be that as it may, wouldn't we all be better off by reducing pollution?"

Nothing, having arguments with people that lack basic critical thinking skills is a waste of time. A simple google search can give you all the data and numbers and you can show it to them but it doesn't matter if they believe they know better than actual scientists. There are people out there that believe the Earth is flat.

I tell people that burning a 100 million barrels of oil a day, everyday, has to have an impact.

Imagine how much exhaust that is everyday.

The idea that burning a million barrels of oil everyday would not have an impact on the atmosphere is absurd.

Maybe show them this:

I told my dad that even if climate change isn't real, or if it is humans don't contribute... what's the harm in doing something about it? What's the harm in doing something to help your grandkids have a world to grow up in and enjoy?

He installed solar panels a few years ago and now likes to talk about how he heats and cools his home without paying ConEd

Save your breath. It's honestly not worth it.

Don't. Nothing you could say is going to change their mind. They'd need to hear it from new sources they trust and their peers and then it still wouldn't be guaranteed they'd reconsider their position. Confirmation bias and a whole host of other brain stuff makes changing someone's mind incredibly difficult. Save your breath.

So... where's the extra heat coming from? If you acknowledge it exists where's it from?

Is it a problem? If it is shouldn't we prevent or prepare for it?

Personally, now I would say 'fine, it doesn't matter what you believe. We are severely fucked and we are going to be lucky to survive. Making one person accept reality is not going to change anything.'

I've become more and more pessimistic.. simon Clark on YouTube has a bunch of accurately hopeful climate content that helps a bit, but so much hinges on 'if we don't actively make it worse' which is exactly what is happening.

My one hope is we will have enough mortally devasting weather before it's too late so that doubters will convince themselves.

We have people like this running Egypt. They're constantly cutting down trees!

Nothing, there's no use in making him feel bad for something he has no control over.

Tell them you're proud of them, they seem to be a high functioning mentally disabled person and are doing great in life.

What if that person think CO2 is good for life?

Just be like, "Okay, what about the pacific garbage patch? Did human activity cause that? Should we be trying to fix it?" It's pretty hard to argue that the fish made all the used water bottles themselves.

Highlight the speed of change now, since industrial revolution, compared to historical data.

Do research. Give them that. Walk away and never think or talk about it with them again.

You can't fix stupid.

Ideally? As little as possible.

Nothing. You benefit more from having someone who will help you plan and prepare for the effects of climate change than you do from having someone who agrees with you about the causes.

The reason for that is you and your comrade can’t do anything impactful about the human sources of climate change.

Ask them what prompted them to be a geologist.

Nothing. Just walk away. I don't understand why people would willingly engage in completely pointless arguments at all... it's a huge part of why I left Facebook and Reddit and come here now instead. People on there literally just to argue and pick fights with other people.

I don't care if it's my dad, my neighbour, or an old friend from school ... if they believe that, they believe that, and nothing I can say is going to change their mind - and it's not my place to change their mind.

If my son said that to me, yes, it is my place to make sure he is properly educated, so we'd go through some Wikipedia articles and/or watch a couple documentaries about it, so people who understand all of it a hell of a lot better than I do can explain it to him properly. I am not a climate scientist.

I tell them their brain is fried and I move on. Nothing will convince these people.

What do they think caused it? Just time passing?

Ozone. 🤷