Amazon rainfall projections ‘underestimated’


Amazonian forests may be less vulnerable to dying off from global warming than feared because many projections underestimate rainfall, Reuters reports.

A study by UK researchers suggested that Brazil and other nations in the region would also have to act to help avert any irreversible drying of the eastern Amazon, the region most at risk from climate change, deforestation and fires.

“The rainfall regime in eastern Amazonia is likely to shift over the 21st Century in a direction that favours more seasonal forests rather than savannah,” the team write in the journal Proceedings of the National Academy of Sciences.

Seasonal forests have wet and dry seasons rather than the current rainforest, which is permanently drenched.

It is argued that this shift in precipitation patterns could result in the emergence of new species of trees, other plants and animals.

The findings challenge past projections that the Amazon forest could die and be replaced by savannah.

The Intergovernmental Panel on Climate Change reported in 2007: “By mid-century, increases in temperature and associated decreases in soil water are projected to lead to gradual replacement of tropical forest by savannah in eastern Amazonia.”

The new study said that almost all of 19 global climate models underestimated rainfall in the world’s biggest tropical forest.

Lowland forests in the Amazon have annual average rainfall of 2,400 mm (94 inches), it said.

Projected cuts in rainfall meant the region would still be wet enough to sustain a forest.

The experts also examined field studies of how the Amazon might react to drying.

It said that seasonal forests would be more resilient to the occasional drought but more vulnerable to fires than the current rainforest.

“The fundamental way to minimise the risk of Amazon dieback is to control greenhouse gas emissions globally, particularly from fossil fuel combustion in the developed world and Asia,” said Yadvinder Malhi, the lead author from Oxford University.

But he said that governments led by Brazil also needed to improve their forest management policies.

Global warming is “accompanied by an unprecedented intensity of direct pressure on the tropical forests through logging, deforestation, fragmentation, and fire use,” the scientists wrote.

And fires, including those touched off by lightning, were more likely to cause wide damage to forests already fragmented by roads or by farmers clearing land to plant crops, such as soya beans.

Source: Reuters

Date: 09/02/2009

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Drought threatens Jordan’s olive trees


Persistent drought in southern Jordan could lead to the decimation of thousands of olive trees in the city of Karak, 120km south of Amman, reports the UN’s IRIN news service.

“We witness in summer a dramatic increase in temperatures and in winter a lack of rain,” said Ahmed Koufahi, executive director of the Jordan Environment Society.

“Our problem will worsen in the future and drought could strike all around the kingdom,” Koufahi told IRIN.

Olive trees could end up dying in the town ahead of the coming winter season, said Abdullah Fadel, a farmer from Iraq town, 20km south of Karak.

“Last year we had little rain during winter. This resulted in a small output of olives compared with previous years, but now we fear that all trees will die because we have not been able to water them for a while now,” said Fadel.

Farmers said at least 30,000 olive trees were on the brink of dying after freshwater springs in the area dried up.

Many farmers resorted to purchasing water from tanks in the city, but the high cost prevented them from splashing out continuously.

“We are still far from the winter season. I don’t know what will happen until the first drop of rain comes, but it looks like all the trees in the town could die,” said Fadel.

At least 20 springs have provided the olive groves with water over the past decades, helping residents turn their town into a small green oasis.

But successive declines in levels of rain water have dried up almost 15 springs, said environmentalists.

Local residents use the springs for washing and cooking as the authorities often ration water to households in cities and towns across the kingdom because of chronic shortages.

In addition, the government has adopted a policy against digging underground water springs in an attempt to preserve water.

According to Aktham Mdanat, head of the Karak agriculture department, the drought is expected to lead to a 50% fall in this year’s olive harvest.

Residents of the town, which has a population of 7,000 people, have called for the construction of dams to help collect as much rainwater as possible during the winter season.

Jordan is one of the 10 most water-impoverished countries in the world.

The desert kingdom has no river capable of providing the country with enough water as the Jordan River has turned into a small stream after its tributaries were diverted by Israel for agricultural purposes, according to Salameh Hiari, a professor at the University of Jordan.

Jordan does not have natural lakes either. It’s population of 5.6m depends solely on rainfall for its water supply.

Source: IRIN News

Date: 17/09/2008

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