<span> The himilayas are an example of an intervening obstacle, but that is an enviromental obstacle. You could have an economic obstacle such as a town along the way that may be in harsh poverty and you may not be able to continue migrating. Or a political obstacle: Migrating through a country that is ruled under a law that despises something about you like race, gender, culture, or personal status.</span>
The united states is going to see a big population growth compared to japan and other countries because alot of immigration is happening both legally and illegally to the united states and will see a population surge of more than 5 billion population growth within 2 years
