Hi Jeff. I'll be brief.
Our planet's climate is complex and interwoven. I don't know if you are a career scientist, but I am. I worked as a weapon systems development scientist, though some of my early studies included biology subjects. It was routine for me to review and assess studies of all manner of military related scientific investigations, covering a lot of territory, without being a subject matter expert across all topics. No one can be. But scientists understand the processes we all use to undertake good research and advance human knowledge. We know that when almost all of the researchers in a particular field (say, climate science) are providing the same advice, there is almost zero chance that they've got it wrong. To ignore this is to be unwise.
It is easy to understand how sensitive our climate is. You mentioned the mini ice-ages. No need for me to provide examples. You're aware of the impact of disruptions, but are you properly considering the consequences of tipping points? The impacts will not be minor. If you're worried about migration now, stand-by! Before then we'll be troubled by food security, fire impacts, or even just insurance costs. Don't buy a house near the coast.
You're right; the lifestyle of a particular individual can't make a difference. To slow anthropogenic climate change will require cooperation by many; billions of individuals, all helping. What I find so disturbingly fascinating is how the American ideals of freedom and individuality so often manifest in the form of selfishness and disregard for the welfare of others who share this beautiful planet. How can burning tyres ever be a sensible thing to do?
All people want freedom but not all of them are selfish. You would lend your neighbour a hose if their house was on fire. We'd see you running in to rescue them. You wouldn't pour petrol on the fire. In this light, how can you be insensitive to peoples' islands being flooded, or whole countries being flooded? The argument, 'There's nothing I can do,' doesn't hold up. Only minor adjustments to your lifestyle would be required to become part of the community that is helping instead of hindering. If you wouldn't pour petrol on your neighbour's house fire, why would you burn tyres? Now extrapolate.
I'm sorry but I don't see humour in your suggestion that we will cancel each other out. Rather, I see one more person who is unable to make the simple connection, 'I'm part of this.'