There are certain boundaries we shouldn't cross to keep our world sustainable. Scientists dub it the Sustainability Doughnut. At our current state we already passed a couple of these boundaries. Some of which being Climate Change and Freshwater Use. Scientists believe that all 9 of these listed below are essential for human survival.
1. Climate Change - The most popular controversy out there. Some believe that it's a problem and some don't. I think it should be fixed.
2. Freshwater use - People don't understand how much water we actually have in the world. How much drinkable fresh water we have.
3. Chemical Pollution - This is any kind of pollution from vehicles polluting the earth with carbon, to drowning the ocean in nitrogen.
4. Land System Change - We're using up too much land on agriculture.
5. Ocean acidification - The increase of carbon dioxide is making the oceans more acidic.
6. Biogeochemical Loading - The 5 cycles, carbon, nitrogen, oxygen, phosphorus, and the water cycle needs to act in equilibrium.
7. Biodiversity laws - We need variety of life in our world. The world isn't made to survive the way humans are living right now.
8. Atmospheric Aerosol loading - Aerosols can affect cloud formation and patterns.
9. Ozone deletion - Ozone destroying chemicals were banned in 1987, preventing anyone from damaging the precious layer.