Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Global Garden Grows Greener

06.06.2003


A NASA-Department of Energy jointly funded study concludes the Earth has been greening over the past 20 years. As climate changed, plants found it easier to grow.


Global change in NPP
Between 1982 and 1999, the climate became warmer, wetter, and sunnier in many parts of the world. These changes increased the overall productivity of land plants by 6 percent. This map shows productivity increases during the time period in green, while decreases are shown in brown. Productivity, which is the net uptake of carbon, increased the most in tropical regions, where climate change resulted in fewer clouds and more sunlight.
Credit: NASA Earth Observatory


Percent change in annual global Net Primary Production (NPP) change from 1982-1999. Purple represents the highest increase (2%) in NPP per year. Areas of blue and red represent decreasing annual NPP. Credit: University of Montana



The globally comprehensive, multi-discipline study appears in this week’s Science magazine. The article states climate changes have provided extra doses of water, heat and sunlight in areas where one or more of those ingredients may have been lacking. Plants flourished in places where climatic conditions previously limited growth.

"Our study proposes climatic changes as the leading cause for the increases in plant growth over the last two decades, with lesser contribution from carbon dioxide fertilization and forest re-growth," said Ramakrishna Nemani, the study’s lead author from the University of Montana, Missoula, Mont.


From 1980 to 2000, changes to the global environment have included two of the warmest decades in the instrumental record; three intense El Niño events in 1982-83, 1987-88 and 1997-98; changes in tropical cloudiness and monsoon dynamics; and a 9.3 percent increase in atmospheric carbon dioxide (CO2), which in turn affects man-made influences on climate. All these changes impact plant growth.

Earlier studies by Ranga Myneni, Boston University (BU), and Compton Tucker, NASA’s Goddard Space Flight Center (GSFC), Greenbelt, Md., also co-authors of the study, reported increased growing seasons and woody biomass in northern high-latitude forests.

Another co-author, Charles Keeling, Scripps Institution of Oceanography, La Jolla, Calif., cautions no one knows whether these positive impacts are due to short-term climate cycles, or longer-term global climate changes. Also, a 36 percent increase in global population, from 4.45 billion in 1980 to 6.08 billion in 2000, overshadows the increases in plant growth.

Nemani and colleagues constructed a global map of the Net Primary Production (NPP) of plants from climate and satellite data of vegetation greenness and solar radiation absorption. NPP is the difference between the CO2 absorbed by plants during photosynthesis, and CO2 lost by plants during respiration. NPP is the foundation for food, fiber and fuel derived from plants, without which life on Earth could not exist. Humans appropriate approximately 50 percent of global NPP.

NPP globally increased on average by six percent from 1982 to 1999. Ecosystems in tropical zones and in the high latitudes of the Northern Hemisphere accounted for 80 percent of the increase. NPP increased significantly over 25 percent of the global vegetated area, but decreased over seven percent of the area; illustrating how plants respond differently depending on regional climatic conditions.

Climatic changes, over approximately the past 20 years, tended to be in the direction of easing climatic limits to plant growth. In general, in areas where temperatures restricted plant growth, it became warmer; where sunlight was needed, clouds dissipated; and where it was too dry, it rained more. In the Amazon, plant growth was limited by sun blocking cloud cover, but the skies have become less cloudy. In India, where a billion people depend on rain, the monsoon was more dependable in the 1990s than in the 1980s.

The climate data for NPP calculations came from the National Oceanic and Atmospheric Administration (NOAA) National Center for Environmental Prediction. Researchers used two independently derived 18-plus-year satellite datasets from the Advanced Very High Resolution Radiometers on NOAA satellite. The team processed and improved the data at GSFC and BU.

"Systematic observation of global vegetation is being continued by NASA’s Earth observing satellites. Earth observing satellites are paving the way to find out if these biospheric responses are going to hold for the future," adds Steve Running, another co-author from the University of Montana.

NASA’s Earth Science Enterprise is committed to studying the primary causes of the Earth system variability, including both natural and human-induced causes.

Krishna Ramanujan | Goddard Space Flight Center
Further information:
http://www.gsfc.nasa.gov/topstory/2003/0530earthgreen.html
http://www.gsfc.nasa.gov/

More articles from Ecology, The Environment and Conservation:

nachricht Dune ecosystem modelling
23.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>