ecological disaster	carbon dioxide	pollutant
ecological catastrophe	sulphur dioxide	air pollutant
endangered species	car exhaust	water pollutant
environmental degradation	greenhouse effect	polluter
environmental destruction	greenhouse gases	pollution
global warming	hazardous substance	air pollution
overpopulation	hazardous waste	noise pollution
overpopulated	litter	water pollution
acid rain	oil slick	radiation
contamination	oil spill	sewage
emission	ozone depletion	raw sewage
untreated sewage	to discharge	forest fire
smog	to harm	hurricane
waste	to poison	landslide
industrial waste	to waste	lava
nuclear waste	avalanche	tornado
toxic waste	cyclone	volcanic eruption
wastewater	disaster	volcano
to be contaminated (with sth)	disaster area
to destroy	drought
to die out	earthquake
to disappear	flood