Global warming or climate change may be debatable, but what is not debatable and is fact is the rate at which human activity is literally destroying hundreds of species each week, hundreds of kilometres of rainforest cut down that will most likely never grow back again, seas lakes and rivers polluted with mercury.. The list doesn't stop.
Soon there will be no tigers, there will be no birds, there will be no more marine life that hasn't been poisoned with mercury, or there may just be none at all. Rather than now all these animals becoming extinct may only affect those that are animal lovers, one day if it carries on it will effect absolutely everyone. The world population won't stop increasing, and soon countries like India and China will be demanding to eat meat on a regular basis. There will be a food shortage.