I feel that in this argument, the onus is on you to provide evidence that most people are ignoring a serious risk.

I don't have a good way of assigning probabilities either, but I feel obliged to try.

I estimate the probability that scarcity of natural resources leads to a fifty percent decline in real GDP per capita in many wealthy countries in the next fifty years is less than one percent.

Conditional on my being wrong, I would be very confused about the world, but at this point would still assign less than a five percent risk of large scale nuclear war between major powers which are both aware there is a very high risk of mutual destruction.

I don't think I'm looking at the world through rose colored glasses. I think the risk of small scale nuclear conflict, or threats such as the use of a bioengineered virus by terrorists, is much greater.