[Multiculturalism]
ageism
ancestors
belief
civil union
convert
descendant
dual citizenship
foreigner
human rights
inequality
mainstream
racial prejudice, racism
sacred
same-sex couple
seek refuge
threaten
tribal conflict

[Other world problems]
poverty, poor
terrorism
economic/financial crisis
homelessness
overpopulation
hunger
starvation (and malnutrition)
genocide (war/conflict)
health
disease: malaria, HIV/AIDS
crime
drugs - addiction

[Natural Disasters]
drought
flooding
earthquake
avalanche
mudslide/landslide
tsunami
heat wave
tornado
hurricane

[Environmental Issues]
oil spill
exhaust fumes
ecological disaster
greenhouse effect
acid rain
ozone layer
global warming
smog
pollution
developing countries
forest conservation 		
water shortage 
climate change
fossil fuels
nuclear power, nuclear meltdown
deforestation
litter
waste
dump/landfill