We don't need to assume a or b. It is the scientific consensus and is as close to fact as you're likely to get.
But regardless, you do realise all the things you're concerned about will be result from the lack of action to address climate change and not becuase of action to tackle it, right?
The availability of resources including land, food, and water will be reduced significantly if we do not change our ways.
How do you think you and your children will cope when as many as 3bn people are displaced by climate related events and extreme weather and are looking for a new place to live?
How will they cope when 1 in 4 people will be living in areas of extremely high water stress, as is predicted to be the case by 2040? And this won't just be some far off places, England specifically is looking down the barrel of a gun with that one, with 12/17 regions expected to face extreme water stress by 2040.
What will they do when global food systems start to collapse? Almost 40% of all calories consumed by humans come from 3 crops (wheat, corn, and rice) and for 2 of them (corn and rice) yields are either predicted to reduce or already are (24% for corn by 2050 and 10% for every 1°C increase in temperature for rice).
If you actually cared about your kids future you would be demanding action now not arguing for the status quo because you think change is hard.
I also think it's a bit disingenuous to say talk about making our kids lives harder when the country has kept the tories in power for the last 13 years, but that's another matter.