This post (in Spanish) wonderfully explains the small amount of water there is in the earth compared to the size of the planet and the even tinier proportion of freshwater.
- In fact, freshwater is less than 4% of the water in earth as 96,54% is in the oceans and seas.
- Almost all the rest is in form of snow/ice, 1.76%, at least for the moment, and underground 1.69%
- The lakes only hold 0.013% of the water, half freshwater, half salty. 130 ppm
- The rivers are even more insignificant with a tiny 0.0002%, 2 ppm of the water. So, if we apply this stupid comment about the small amount of 450 ppm of CO2, we would have been lost as we depend on roughly 72 ppm of freshwater. I know this is nonsense, it is just to remember that in some cases ppms are critical.
Most dramatic consequences of climate change are related with water somehow: droughts, extreme rainfalls, floods,… Being conscious of the big figures can help us remember how delicate are water equilibria.