Friday, August 14, 2009

Greenland ice sheet

The Greenland Ice Sheet is a vast body of ice covering roughly 80% of the surface of Greenland.


It is the second largest ice body in the world, after the Antarctic Ice Sheet.

The ice sheet is almost 2,400 kilometres long in a north-south direction, and its greatest width is 1,100 kilometres at a latitude of 77° N, near its northern margin.

The ice sheet, consisting of layers of compressed snow from more than a hundred thousand years, contains in its ice today's most valuable record of past climates.

In the past decades, scientists have drilled ice cores up to three kilometres deep.

With the ice cores, scientist have obtained information on (proxies for) temperature, ocean volume, precipitation, chemistry and gas composition of the lower atmosphere, volcanic eruptions, solar variability, sea-surface productivity, desert extent and forest fires.

This variety of climatic proxies is greater than in any other natural recorder of climate, such as tree rings or sediment layers.

The Greenland Ice Sheet has experienced record melting in recent years and is likely to contribute substantially to sea level rise as well as to possible changes in ocean circulation in the future..

Wednesday, August 5, 2009

Bolivia’s Indians feel the heat

Mount Illimani looming over the village of Khapi. Photo: Mark Chilvers
Many believe Mt Illimani will have completely lost its glaciers in a few decades

By James Painter
BBC News, Khapi, Bolivia

Marcos Choque is a 67-year-old Aymara Indian with holes in his trousers and battered sandals. He appears remarkably cheerful.

Sitting among his fellow villagers from Khapi, perched high up in the Bolivian Andes, he seems to delight in cracking jokes.

But ask him about Illimani - the 6,400m (21,000-ft) mountain that towers above his village - and his mood turns more sombre.

map

"When I was young, the snow often came down as far as there," he says, pointing to the hills. "But in the past few years, the snow-line has risen 500m. It's getting hotter, which is melting the mountain."

Mr Choque and the 40 families that make up his community have been watching Illimani with increasing alarm. They depend on it for part of their water supply - both to drink and to irrigate their small, terraced parcels of land.

"We calculate that there will be no snow or ice left on Illimani in the next 30 or 40 years. It will be black, or what we call peeled of its whiteness," he says.

Water supply worries

The glaciers on Illimani are estimated to have been there for thousands of years. Its white peaks tower over the nearby city of La Paz, Bolivia's administrative capital.

Many of La Paz's residents swear the snow-line is gradually creeping upwards.

38-year-old Lucia Quispe and son. Photo: Mark Chilvers
If we don't have water, how will we live? Water is life
Lucia Quispe

Some were shocked when a newspaper recently published a photo of what Illimani could look like in 2039 - with no sign of any whiteness on top.

Hydrologists from La Paz are planning to measure the glacial loss of the mountain. They already know that the nearby glacier of Mururata has lost more than 20% of its surface area since 1956 due to higher temperatures, and probably a greater percentage of its volume.

Earlier this year, the Paris-based Development Research Institute (IRD) estimated that the glaciers in the Cordillera Real mountain range in Bolivia, of which Illimani forms a part, had lost more than 40% of their volume between 1975 and 2006.

The IRD said that the volume had remained pretty constant until 1975, but had diminished quickly since then.

If this tendency continued, the IRD said, it could have a very negative impact on the water supply in the dry season to some cities like La Paz.

Unpredictable

In the case of Khapi, the water from Illimani plays a crucial role in the life and religious beliefs of the community.

Every September, they carry out a ritual, involving offerings called Waxt'a in Aymara. This includes the sacrifice of a llama and other offerings like coca leaves, alcohol and cigarettes to Illimani.

They go through the elaborate ceremony so that, in their words, "Illimani gives them water through the year".

18-year-old Rogelio Churqui Quispe from Khapi tends his plot of parsley. Photo: Mark Chilvers
For Khapi residents such as Rogelio, Mt Illimani is a lifeline

The villagers think that the snow and ice from Illimani accounts for up to half of their annual water supply, although they are not sure.

Bolivian scientists are trying to answer the crucial question of just how much of the water comes from glacial melt at different times of the year. Precipitation and underground aquifers provide the rest.

The more immediate concern of the villagers is the changing climate. They say there is no longer any predictability about when the rains come, compared to the past. And they are sure that there is less rain, and that the weather is getting hotter.

Theirs is not the international language of global warming and carbon emissions.

"Our weather is coming up from where it used to be further down," says Severino Cortez, a community leader, pointing down the mountain from Khapi, which is 3,600m high.

Not everything is bad news. The warmer temperatures mean that some of them can now grow peaches and maize where previously they could not.

Vulnerable

But the Khapi villagers are very worried for the future. "I am getting old," says Marcos Choque.

"I am not going to see Illimani melting away completely, but the young will."

Lucia Quispe, a 38-year-old mother of three, wonders where the water will come from to irrigate her plot of land, where she grows potatoes, maize and beans.

"I am sad and very worried when I think about the future of my children," she says. "If we don't have water, how will we live? Water is life."

67-year-old Marcos Choque. Photo: Mark Chilvers
Marcos Choque fears his children will see Illimani bare of glaciers

Non-governmental organisations working with Khapi and other nearby communities high up in the Andes say it is particularly unjust that Aymara villagers will suffer the fall-out from global warming when they are amongst the least responsible for it.

Some of the communities are active members of a new civilian pressure group formed this year, called the Platform of Civil Society against Climate Change.

One of the Platform's demands is for the formation of an international tribunal on climate justice, and for an international compensation fund for victims of climate change.

"What's happening at Khapi is typical of what hundreds of poor, indigenous and vulnerable communities throughout Bolivia, Peru and Ecuador are facing," says Juan Carlos Alurrade, executive director of Agua Sustentable (Sustainable Water), which is helping communities to adapt to climate change.

"They depend on glacial melt for irrigation, but the glaciers are doomed."

Monday, August 3, 2009

India monsoon rain 'below normal'


A farm in India
There are fears of drought if the rains are patchy

Indian officials say that monsoon rains in the country are likely to be "below normal" triggering off fears about crop failure and high food prices.

Forecasters say that rainfall is likely to be lower than predicted in April, when they said it would be near normal.

The government says there is no need for panic, and that heavy rains in July are likely to avert a drought.

A heat wave is sweeping the country and rains are delayed in many parts. Rains usually last from June to September.

"It [the monsoon] is late," federal minister Prithviraj Chavan told reporters.

North-west India appeared to be worst affected by the slow rains with only 81% rains forecast.

Critical

Monsoon rains are critical to India's farm prospects, which account for a sixth of economic output.

Up to 70% of Indians are dependent on farm incomes, and about 60% of India's farms depend on rains. Irrigation networks are dismissed by critics as inadequate.

The summer rains are crucial to crops such as rice, soybean, sugarcane and cotton.

The Indian media has been full of reports about the patchy rains so far.

Delhi heat wave
A heat wave is scorching the country

"Praying for rain, bracing for worst" headlined the Hindustan Times on its front page on Wednesday.

The newspaper said that in at least eight states, monsoon rains so far had been 60 to 90% below normal.

"There is concern but no worry as yet. There is still time," Farm Secretary T Nanda Kumar told the newspaper.

One analyst said delay in the rains in some parts of India could hit economic growth.

"Delay in monsoon will play the spoilsport and may hit GDP by at least 1 to 1.5 percentage points," stockbroker VK Sharma, told the Reuters news agency.

Economists agree that the delay will cause further stress in a country where food prices are already high.

"The delay is not a good signal. Food prices are already high and any delay could push food prices higher. Food price inflation could emerge as a concern," said DK Joshi, principal economist at credit ratings agency Crisil.

Politicians in many states are holding special prayers for the rains - the farm minister in central Chhattisgarh state held a prayer for the state to get rains soon.