1) If we pollute the water -> we will have no fresh water to use
2) If you cut down the trees in the forests -> there will be big floods every year
3) If there is too much exhaust fume in the air -> more and more people will cope with respiratory problems
4) If you keep your neighborhood clean -> you will have an ideal to live
5) If people stop using dynamite for fishing -> a lot of sea creatures will be well preserved