Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 


Man’s impact on planet enigmatic


Man’s share of the earth’s resources is hard to gauge.
© Photodisc

Environmental even keel or global crisis - no one knows.

... mehr zu:
»But »Earth »Human »NPP

Calculating man’s impact on the planet is difficult. So it’s hard to say whether we are on an environmental even keel or hurtling towards a global crisis, new research concludes.

The slice of global land net primary productivity (NPP) - a measure of the food and carbon-containing resources that land plants make available - that humans consume could be 10 per cent or 55, according to Stuart Rojstaczer and colleagues at Duke University in Durham, North Carolina1.

"[The research] highlights the incompleteness of our understanding of the whole Earth system," says Chris Field, who studies global ecology at Stanford University in California.

Global NPP is shared between man and the rest of life on the planet. "The fraction appropriated by humans indicates the breadth of our actions and suggests the fraction left for other species," says Field.

An influential 1986 study put that fraction at 32 per cent - alarmingly high according to many experts, especially given projected increases in the global human population2. Taking into account the share of NPP required by other organisms, man’s consumption seemed close to the total capacity of the planet.

Rojstaczer’s team set out to update this assessment using the latest satellite data on agriculture, grazing and forestry. Using the latest satellite data on agriculture, grazing and forestry, they extrapolated results from small-scale studies of land use. They also estimated the uncertainty of the measurements used in their model.

They too came up with 32 per cent for man’s average appropriation of NPP. But many of the factors that give rise to this figure are highly uncertain, they warn.

Farming out

Measuring agricultural productivity accurately on a global scale is particularly fraught, the team found. Variations in fertilizer use, irrigation and crop type mean that productivity can vary as much as fivefold, they say. Man’s use of, and impact on, tropical forests is also very hard to gauge.

Nonetheless, the new study "gives the best feel for the most likely impact", says Field. What’s more, it identifies the areas where hard facts are lacking.

Field suspects that 32 per cent may still be an underestimate. Calculations do not yet include factors such as climate change and pollution, which may significantly alter plant growth and therefore NPP. But it is clear, says Field, that humans take a huge slice of NPP - "probably more than any other species in Earth history".

Estimates of NPP consumption can only improve as better data become available from satellites and agricultural ministries. Until then, says Rojstaczer, "the magnitude of the human footprint on Earth is open to much speculation".


  1. Rojstaczer, S., Sterling, S. M. & Moore, N. J. Human appropriation of photosynthesis products. Science, 294, 2549 - 2552, (2001).
  2. Vitousek, P. M., Ehrlich, P. R. & Matson, P.A. Human appropriation of the products of photosynthesis. Bioscience, 36, 368 - 373, (1986).

TOM CLARKE | © Nature News Service
Weitere Informationen:

Weitere Berichte zu: But Earth Human NPP

Weitere Nachrichten aus der Kategorie Ökologie Umwelt- Naturschutz:

nachricht Ökobilanzstudie: Mehrwegtransportverpackungen schonen die Umwelt
15.03.2018 | Fraunhofer-Institut für Umwelt-, Sicherheits- und Energietechnik UMSICHT

nachricht Mikropartikel aus Kunststoff im Einzugsgebiet von Rhein und Donau nachgewiesen
15.03.2018 | Hessisches Landesamt für Naturschutz, Umwelt und Geologie

Alle Nachrichten aus der Kategorie: Ökologie Umwelt- Naturschutz >>>

Die aktuellsten Pressemeldungen zum Suchbegriff Innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Bewegungskontrolle mit Fotopigmenten

Forscher der Universität Göttingen entdecken zusätzliche Funktion von Opsinen

Die Fotorezeptoren in den Augen von Tieren fangen Licht mithilfe von Fotopigmenten ein. Forscher der Universität Göttingen haben nun entdeckt, dass diese...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Neue Methode der Röntgenholographie

Röntgenholographie im Flug - Eine neue Methode der Röntgenholographie erzeugt Bilder von Partikeln in der Gasphase

Wissenschaftlerinnen und Wissenschaftler in der Arbeitsgruppe von Prof. Thomas Möller am Institut für Optik und Atomare Physik der TU Berlin ist es gemeinsam...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Alle Focus-News des Innovations-reports >>>



Industrie & Wirtschaft

Ultraschneller Funk und Chip Design bei der DATE-Konferenz 2018 in Dresden

16.03.2018 | Veranstaltungen

Arktis, Antarktis und Hochgebirge unter Druck

16.03.2018 | Veranstaltungen

Internationale Spring-Campus-Konferenz an der Freien Universität Berlin vom 9. bis 13. April 2018

15.03.2018 | Veranstaltungen

Wissenschaft & Forschung
Weitere VideoLinks im Überblick >>>
Aktuelle Beiträge

Per Erbgut-Schalter Alzheimer aufhalten

16.03.2018 | Biowissenschaften Chemie

Mobiler Roboter pflegt Fassadenbegrünung

16.03.2018 | Biowissenschaften Chemie

UV-Kugel macht Lackieren einfach und schnell

16.03.2018 | Verfahrenstechnologie

Weitere B2B-VideoLinks
im innovations-report
in Kooperation mit academics