Can you provide the citations for that? Migration forecasts are absolutely enormous [1] and 10 million seems very low in terms of relation to the numbers and how humanity will react to it all. Just think of the current reactions to migration currently and multiply that 10-fold or more. And I can see that happening in the next 20 years.
I mean there are a bunch of studies and articles, with an extreme wide range. It also difficult to count. For instance if a heat wave leads to heart attack in an obese person, should that be included, etc.
Thanks. For me, I just do not think humanity in its current state could handle the the massive amount of migration that could potentially happen without ugly political upheavals and conflict. I guess we will find out.
[1] this is just one I found from a quick search, there is a lot more out there: https://www.theguardian.com/news/2022/aug/18/century-climate...