The amount of fresh water on the Earth would fit into…
And over 7 billion people have a straw in the same grain of salt. Some speculate that competition for control of this limited supply between countries could eventually lead to famine, war, or worse. There’s some evidence it’s happening already.
Making sure we preserve clean drinking water for future generations, and figuring out how to distribute it to the people who need it most, are huge challenges that we’ve only just begun to address.
2. How acidic the oceans are becoming.