Biodiversity tends to increase with the area of land or water conserved and intact ecosystems play a major roles in mitigating climate change. Yet only 16% of global land is in protected areas. In the US, it’s closer to 12%. In many places in the world it is as low as 7%.
The 30x30 goal set by 50+ countries to conserve 30% of land and water by 2030 is a great start but not enough. In fact, there’s no specific scientific basis for 30%.
Estimates from studies considering a wide set of biodiversity values suggest that 30 to 70% of land and water should be under some sort of protection. The call for 50% of the Earth is a mid-point of these values and is supported by a range of studies.
Conservation does not exclude humans from these areas, it simply focuses on the importance of protecting rich ecosystems before they are bulldozed, drained, deforested, or abandoned.
As an example, Marine Protected Areas restore and enhance commercial fisheries in and out of the MPA, provide recreation and tourism income as well as numerous spiritual and cultural values.
A biogeographic scan of Earth’s principal habitat shows that a full representation of its ecosystems and the vast majority of its species can be saved within half the planet’s surface. At one-half and above, life on Earth enters the safe zone. Within half, existing calculations from existing ecosystems indicate that more than 80 percent of the species would be stabilized.
Half Earth by EO Wilson
A goal is not always meant to be reached, it often serves simply as something to aim at.
Bruce Lee