As life becomes more difficult for people to survive in China and parts of South America and Central America more people will migrate north to the U.S.

Right now over 10,000 migrants through the Mexico border show up in the U.S. every day but I think this number can only rise over the years unless the U.S. pays Mexico to slow the traffic of people down heading north. And this is very possible that this is exactly what the U.S. will do over time since there is no humane way to handle this problem, passing it off onto the Mexican Government to stop people from heading north might be one solution that the U.S. reverts to to prevent basically 30 times 10,000 people from sneaking across the border monthly or 300,000 people entering the U.S. illegally each month. 

To think that these numbers won't continue to increase over time is to be unrealistic.Why?

Because of Global warming destroying people's ability to farm without canals and rivers. There is no longer enough predictable rain coming down around the world. So, it is either flooding or droughts and light rains which is what crops need isn't happening as much around the world. So, crops are either drying up or they are flooded out instead. As a result people can stay where they are and starve to death or be killed by roving Gangs or they can come to Europe or the U.S. or other developed richer countries in an attempt to survive at all.

So, people trying to come to where they might survive will eventually cause millions of people to be on the move worldwide by 2025 or 2030. Global Warming is killing people mostly through droughts and flooding and starvation now worldwide. So, preparing for these kinds of problems is for many a matter of life or death for both the people living in developed countries and for those desperate people trying to come to more developed countries in order to survive at all.