Climate Change Already
Affecting Plants, Farms and Habitats
May 09, 2005 — By Cooperative Research Centre for Greenhouse Accounting
CANBERRA, AUSTRALIA — Climate change is already affecting the growth of
plants, the productivity of farms, and habitats for animals, according to a
Communiqué from a meeting of about 80 research scientists from across
Australia.
The scientists, members of the Cooperative Research Centre for Greenhouse
Accounting, issued the Communiqué from their 2005 Annual Science Meeting.
"Atmospheric temperatures are increasing, oceans are becoming warmer, sea
levels are rising, rainfall patterns are changing. The amount of sunlight
reaching the earth's surface directly is falling, as are evaporation rates from
land-based water bodies and potential evaporation rates from the soil and
vegetation," they said.
Releasing the Communiqué, CRC for Greenhouse Accounting Chief Executive Dr
Michael Robinson stressed both the urgent need for action to address global
climate change, and the scale of actions required. "Even 50 per cent
reductions in global emissions of greenhouse gases would see carbon dioxide
levels in the atmosphere rise to about three times their natural levels,"
he said. "Over the past six years the Cooperative Research Centre for
Greenhouse Accounting has made significant advances in developing our
understanding of how forests, farms, grasslands and woodlands can play a part in
the battle to limit climate change and its impacts."
In their Communiqué, the scientists said sustainably managed forests, farms and
grasslands had the capacity to ameliorate climate change by storing more carbon
in soils, plant material and wood products, effectively removing significant
amounts of the major greenhouse gas carbon dioxide from the atmosphere.
But they warned that water, nutrient and temperature stresses common in
Australia and global dimming - the widely observed decrease in direct sunlight
arriving at the earth's surface over recent decades - could inhibit the enhanced
plant growth which might otherwise have been expected from increasing
concentrations of carbon dioxide in the atmosphere.
As a result, plants could act as a positive feedback mechanism, exacerbating
rather then ameliorating the changes in climate.
"Likewise, if climate change increases the frequency and extent of fire in
Australia, some of the large quantities of carbon stored in vegetation and soil
will be released to the atmosphere in the form of greenhouse gases," they
said.
They said that while scientific knowledge was much improved, many uncertainties
remained and continued research was vital. " While we have identified some
plant responses to atmospheric and climate changes, our understanding of
underlying causes is far from complete. The cause of global dimming and its
future course remain subject to scientific debate. Further fundamental research
is required if we are to reduce the many uncertainties in our understanding of
how plants and soils will respond to continuing increases in the concentrations
of greenhouse gases in the atmosphere and the resulting changes in
climate," the Communiqué said.
"Understanding of plants' interaction with climate change is central to
sustainable management of our landscapes, productivity of our farms, and in the
battle to minimise adverse impacts from our emissions of greenhouse gases."
The text of the Communiqué can be found at www.greenhouse.crc.org.au/crc/ecarbon/communique_050508.cfm.
For more information, contact:
Bruce Wright
Program Manager - Communication and Education
Cooperative Research Centre for Greenhouse Accounting
Phone: +61 2 6125 5593
Fax: +61 2 6125 5095
Mobile: 0412 632 703
bruce.wright@greenhouse.crc.org.au
www.greenhouse.crc.org.au