10 Sept 2001
Studart L. Pimm's The World According to Pimm: a scientist audits the Earth (McGraw-Hill 2001) is an extraordinarily useful and timely book in the contexts of Human Geography and Global Stewardship. I discovered it via Peter Raven's review in Science, and read most of it during the weekend. Many of the sources Pimm cites are available to W&L readers in online full text, so I decided to gather many of them onto a page.

Pimm's 'Ledger of Biological Accounts' can be summarized in a series of estimates of global activity, which I quote:

  1. We eat about 1 billion tons of plant growth each year.
  2. Our domestic animals eat about 2 billion tons of plant growth each year.
  3. We consume about 2 billion tons of plant growth each year for wood and fuel.
  4. Croplands produce 26 billion tons of biomass each year.
  5. Our cities and roads cover an area that would have generated 3 billion tons of biomass each year.
  6. Forests converted to grazing lands account for 3 billion tons of plant production each year.
  7. Temperate and boreal forests are harvested, burned, and otherwise used to an amount equivalent to three-quarters of a billion tons each year.
  8. Tree plantations account for 3 billion tons of biomass used each year.
  9. Some 160,000 km2 of tropical forest are cleared each year.
  10. Fires burn and selective logging and fragmentation damage areas several times larger than the area of forest cleared each year.
  11. At least 5 million km2 of tropical forest have been converted to pastures, degraded, or otherwise changed from their original state.
  12. Salt accumulation destroys about 15,000 km2 of irrigated land each year, and it diminishes the potential biomass production across 450,000 km2.
  13. Agricultural practices destroy about 20,000 km2 of rain-fed cropland each year, and they diminish the potential biomass production across 2 million km2.
  14. About 6 million km2 of pasture lands are burned each year.
  15. Grazing has degraded biomass production across 35 million km2 of dryland.

It's instructive to glance through the sources Pimm uses. Linked here are only those we have online access to:

Pimm starts from the global biomass figures presented in
Vitousek et al. 1986
Human appropriation of the products of photosynthesis (BioScience 36:6:368-373),
which he identifies as "the first scientific effort to approach these big numbers... a brilliant paper, one of the most important of the twentieth century" (pg. 10).

Olson et al. 1985
Carbon in Live Vegetation of Major World Ecosystems Report ORNL-5862. Oak Ridge National Laboratory, Oak Ridge, Tennessee

Field et al. 1998
Primary Production of the Biosphere: Integrating Terrestrial and Oceanic Components (Science 281, Number 5374, Issue of 10 Jul 1998, pp. 237-240)

Ehrlich and Holdren 1971
Impact of Population Growth (Science Vol. 171, No. 3977. (Mar. 26, 1971), pp. 1212-1217) (I=PAT : Impact equals number of people times consumption or affluence per person times technologies used to supply consumption)

Skole and Tucker 1993
(290-odd citations since 1996) Tropical Deforestation and Habitat Fragmentation in the Amazon: Satellite Data from 1978 to 1988 Science, New Series, Vol. 260, No. 5116. (Jun. 25, 1993), pp. 1905-1910. (290-odd citations since 1996)

Hahn et al. 2000
AIDS as a Zoonosis: Scientific and Public Health Implications Science Volume 287, Number 5453, Issue of 28 Jan 2000, pp. 607-614

Pimentel et al. 1995
Environmental and Economic Costs of Soil Erosion and Conservation Benefits Science Vol. 267, No. 5201, Feb. 24, 1995 pp. 1117-1123

Kessler et al. 1978

Bousquet et al. 2000
Regional Changes in Carbon Dioxide Fluxes of Land and Oceans Since 1980 Science 2000 November 17; 290: 1342-1346

Fung 2000
Variable Carbon Sinks Science Volume 290, Number 5495, Issue of 17 Nov 2000, p. 1313

Postel et al. 1996
Human Appropriation of Renewable Fresh Water (Science 271:785-788) (86 citations)

Dynesius and Nilsson 1994
Fragmentation and Flow Regulation of River Systems in the Northern Third of the World (Science 266: 753-762) (124 citations )

Micklin 1988
Dessication of the Aral Sea: a water management disaster in the Soviet Union. Science 241:1170-1176

Daly and Smith 1993
Physical-Biological Interactions Influencing Marine Plankton Production, Annual Review of Ecology and Systematics, Vol. 24, 1993 pp. 555-585

Goldammer 1999
Forests on Fire (Science Volume 284, Number 5421, Issue of 11 Jun 1999, pp. 1782-1783. )

Cochrane et al. 1999
Positive Feedbacks in the Fire Dynamic of Closed Canopy Tropical Forests (Science Volume 284, Number 5421, Issue of 11 Jun 1999, pp. 1832-1835. )

Stone 1999
Coming to Grips With the Aral Sea's Grim Legacy (Science Volume 284, Number 5411, Issue of 2 Apr 1999, pp. 30-33. )

Pauly et al. 1998
Fishing Down Marine Food Webs Science Volume 279, Number 5352, Issue of 6 Feb 1998, pp. 860-863

Hardin 1968
The Tragedy of the Commons Science Vol. 162, No. 3859. (Dec. 13, 1968), pp. 1243-1248

Casey et al. 1998
Near Extinction of a Large, Widely Distributed Fish Science Volume 281, Number 5377, Issue of 31 Jul 1998, pp. 690-692 (barndoor skate) (see also HISTORICAL EXTINCTIONS IN THE SEA James T. Carlton et al. Annu. Rev. Ecol. Syst. 1999. 30:515-538.

Baker et al. 2000
Scientific Whaling: Source of Illegal Products for Market? Volume 290, Number 5497, Issue of 1 Dec 2000, pp. 1695-1696

Baker and Palumbi 1994
Which Whales Are Hunted? A Molecular Genetic Approach to Monitoring Whaling Science Vol. 265, No. 5178, Sep. 9, 1994

Klicka and Zink 1997
The Importance of Recent Ice Ages in Speciation: A Failed Paradigm Science 1997 September 12; 277: 1666-1669

Steadman 1994
Prehistoric Extinctions of Pacific Island Birds: Biodiversity Meets Zooarchaeology Science vol 267 pp. 1123-1131

Some Web pages:

Central Asia Research and Remediation Exchange (CARRE) at San Diego State University (Aral Sea in detail)

Butakoff's 1853 map of Aral Sea

Coastal Zone Color Scanner ("This data set is historical global ocean color data observed from Nimbus-7 satellite. During the 91 months of its operation (October 1978 - June 1986), CZCS acquired nearly 68,000 images, each covering up to 2 million square kilometers of ocean surface.")

SeaWiFs, the successor to CZCS

12 Sept
Today's mail brought the 7 September issue of Science, in which is an article that addresses issues absolutely central to Global Stewardship: Humans as the World's Greatest Evolutionary Force (Stephen R. Palumbi Issue of 7 Sep 2001, pp. 1786-1790). The first article cited in the text is Human Domination of Earth's Ecosystems (Peter M. Vitousek, Harold A. Mooney, Jane Lubchenco, Jerry M. Melillo Science Volume 277, Number 5325, Issue of 25 Jul 1997, pp. 494-499). The 'Similar articles found in Science' feature for the latter article is similarly instructive.