Preserving Biodiversity

For the environmental controversy you read and researched ecological restoration. Keeping with that topic, only about 12% of the Earth's land area has been set aside as parks and nature reserves, a lot of this land is unprotected from human intruders or includes areas with low biodiversity (glaciers, tundra, and deserts). To maintain the Earth's biodiversity, many environmentalists want at least 20% of the Earth's land area, including examples of all major biomes, protected from human exploitation.

Opponents argue that it's too expensive and difficult to effectively protect 20% of the Earth's land area from billions of people. Resources are needed to support people in developing countries. Greedy or impoverished individuals would simply poach and illegally cut timber in the expanded reserves.

Do you agree or disagree that 20% of the Earth's land area should be put aside, or is it to difficult to protect that much land? Please explain your answer.