Serious addendum: Sweden, Norway and Finland have population densities lower than Brasil, and I think we should all expect to take in at least 100 million climate refugees during the next few decades. Another reason why we need to keep the countryside communities alive.

@Loukas I think the vast majority of people have yet to start understanding this.
The largest human migration ever is starting. And the response needed isn't machine guns at the borders & telling the coast guard to sink ships with refugees on them.
The action needed is the plan for the growing cities and growing need for (sustainable) logistics.