US: NASA satellite images have revealed that the biosphere is under increasing strain due to rising population and consumption of crops and animals. If the situation continues at present rates then by 2050 more than half of the new plant material generated on Earth each year will be required for humans. These findings were presented by NASA scientists at the American Geophysical Union (AGU) Fall Meeting.
Marc Imhoff of the NASA Goddard Space Flight Center presented the results of a global survey for 1995–2005. Using data from NASA’s AVHRR and MODIS satellites, Imhoff and his colleagues tracked the amount of plant material produced on Earth. These satellites scan the Earth at 600 km a second, monitoring the colour of light emitted from the surface; light near the green part of the spectrum is taken to indicate the presence of vegetation.
To create a “currency” for natural consumables, the researchers considered plants and animals in terms of the amount of carbon that they draw from the atmosphere – referred to as “net primary-production (NPP) carbon”.
Imhoff believes that the need for more plant products will have big implications for land management. As more land is required for agriculture, planning authorities will be faced with difficult decisions as they try to protect important ecosystems, such as boreal forest.
Rama Nemani, another member of the NASA team believes that the next generation of Earth-monitoring satellites will play a key role in informing these discussions. These will include NASA’s National Polar-Orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project and ESA’s Sentinel satellites.
Nemani also said that he would like to see the creation of an international body to monitor global biodiversity, in the same way that the climate is assessed by the IPCC – Intergovernmental Panel on Climate Change (IPCC).