【7】The impact of climate change on water system

• The cryosphere—the frozen water on Earth—is melting. A warmer atmosphere causes the planet's snow pack, glaciers and sea and freshwater ice to melt at an accelerated pace. Melting glaciers and polar ice sheets contribute to sea level rise. As the ice melts, it also exposes more dark ocean waters, which absorbs more sunlight than ice, and thus heats the ocean more, triggering a cycle of melting and heating.

• Weather of all kinds is getting more extreme: The increased evaporation of water is like fuel for storms, exacerbating extreme weather events, such as hurricanes. Rising sea levels make coastal flooding events worse. In more naturally arid areas, droughts and wildfires intensify.

• The oceans are getting hotter, expanding, and becoming more acidic: The oceans are getting hotter, because they soak up 90% of the extra heat in the atmosphere. This causes the oceans to expand, and this also contributes to higher sea levels. Meanwhile, the increased concentration of carbon dioxide in the ocean triggers a chemistry change that makes the water more acidic. The ocean is almost 40% more acidic than it used to be.