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Climate Change Already Affecting Plants, Farms and Habitats |
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CANBERRA, AUSTRAILIA, May. 9 -/E-Wire/-- 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.
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The scientists, members of the Cooperative Research Centre for Greenhouse Accounting, issued the Communiqué from their 2005 Annual Science Meeting.
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"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.
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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."
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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.
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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.
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As a result, plants could act as a positive feedback mechanism, exacerbating rather then ameliorating the changes in climate.
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"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.
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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.
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"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."
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The text of the Communiqué can be found at http://www.greenhouse.crc.org.au/crc/ecarbon/communique_050508.cfm
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