Immigration and the Environment
I'm very pro-European. I favour a federal European state and hope that one day the European Union will grow to become a world government, yet even I don't support free movement of people throughout Europe. Firstly, if Europe did expand to become a world government then there would be no immigration controls at all; which history has shown not to work, and secondly the link between free movement of goods and the free movement of people is tenuous. People could be considered goods in a service economy, and free movement would boost economic prosperity, but people are far more than economic units.
Ultimately, over-population is an environmental issue and the environmental problems the world is sufferering at the moment; principally mass-extinction due to habitat loss, and global warming, are caused by human over-population. Immigration controls exist to preserve local environments, that is all. Countries can exist with very dense populations, but this is harmful to both their and the global environment.
The word environment also means the human environment and well-being, countries can feel 'too full' of people, and animals appear to have an instinctive notion of a population of the right size. Perhaps this feeling the root of anti-immigration feelings, an instinctive preservation of space. Perhaps feelings of wanting to keep things as they are, a resistance to change, reflects an unconscious desire to limit population growth.
Population growth and immigration controls are destined to be the two biggest issues of the 21st century, and this is because of their impact on the environment. Environmentalists perhaps think, due to urgency, that politicians are not taking global environmental issues seriously, but even now, most international political business concerns it. Environmental issues are principally the balance between economic growth and population growth, and perhaps even issues like terrorism and the current pandemic have a cause in population imbalances, economic imbalances, and immigration; these are ultimately, therefore, environmental issues.
Population controls and immigration controls will be necessary components of a long term, sustainable solution to global environmental problems.