Push and pull factors!
These include...
Government: Push
People are fleeing governments who aren't
ruling in the interest of their people or are treating different groups poorly for reasons of ethnicity,
religion, or political opinion. For example, more
than one million people have left Burma where the military government is treating different ethnic groups, or groups fighting for democracy poorly.
Religion: Push
Freedom of religion is a basic human right but some states do not accept
other religions and often actively treat those with different
religious beliefs poorly. Many Christians are leaving states in the Arab world
or Middle East because of bad treatment because of religion, for
example in Egypt, Iraq and Iran.
Nature: Push
Bad environment, climate change, limited
access to water, bad food production are factors forcing many people to leave their countries and will be the main cause
for migration in the coming decades if nothing is being done to prevent
the effects of climate change. Whole islands might dissapear in
increasing water levels. For example, the President of the Maldives, an
Indian Ocean island, has already publicly stated that he may have to
look for land elsewhere if his country "drowns".
Nature: Pull
Conversely, many people will leave for better environments where it
is possible to create living conditions conducive to a better life and
future. However, such moves will eventually cause further pressures on
availability of good land, water and public facilities and may again
lead to onwards migration.