Planet Earth produces over 100 billion metric tons of new plant matter on land each year.

And humans consume about 20% of it as food, fuel and construction materials – according to a 2004 study by Marc Imhoff of Goddard Space Flight Center and his colleagues. Other studies have estimated 50%. Imhoff’s team plotted human consumption of plant materials on a map of the world.

Marc Imhoff: And then what we saw was that many areas of the Earth where you have high populations are of course consuming far, far more than the local landscape could provide.

In some cities, people consume 300 times as much material from plants as local plants can provide. And that puts pressure on ecosystems far from people.

Marc Imhoff: . . . we could look at the interplay between consumption and supply and how dependent we are . . . just as a human culture on this planet, on transportation systems and agricultural production systems that produce a huge amount of food and fiber in other areas and then transport it to the areas where we all live.

And total global consumption of plant material is increasing. Imhoff suggests that technology might help limit the effects of our rising consumption by, for example, making agricultural harvesting more efficient.

Special thanks to NASA – explore, discover, understand.

Our thanks to:
Dr. Marc L. Imhoff
ESSP Project Scientist
NASA Goddard Space Flight Center
Greenbelt, MD