For example, when an oxygen atom binds to one of hemoglobin's four binding sites, the affinity to oxygen of the three remaining available binding sites increases; i.e. oxygen is more likely to bind to a hemoglobin bound to one oxygen than to an unbound hemoglobin.
These are all phases of cells multiplying without this we would all be one cell organisms
Rainfall will increase due to rising temperatures which will increase the risk of flooding.