Category: Climate change

Extreme weather could become norm around Indian Ocean

One more example of how countries in the poor part of the world will be hit by extreme weather and natural disasters as the globe heats up.

This study shows that there is a great likelihood that the weather in countries around the Indian Ocean is becoming more extreme due to cyclical changes in the ocean temperatures and the impact these have:

What do the torrential rains that swept across a swathe of East Africa in 1997 have in common with the record-breaking drought that Australia has just emerged from? Both can be blamed on El Niño’s Indian Ocean sibling.

A study looking at how climate change will affect this ocean oscillation pattern has predicted that if the world is allowed to warm uncontrollably, these kinds of extreme events will become the norm by 2050.

The Indian Ocean Dipole (IOD) is an oscillation of warm water across the equator. In the oscillation\’s positive phase, sea surface temperatures in the Arabian Sea rise whereas temperatures around Sumatra, Indonesia, fall. In the negative phase, it’s the other way around.

As well as being blamed for Australia’s recent dry spell and the 1997 East African storms, the IOD\’s positive phase has been linked to droughts in Australia and dry weather in Indonesia over the last 6500 years, according to a 2007 study of fossilised coral. The study also concluded that positive events are becoming more frequent, with an unprecedented 11 occurrences over the past 30 years.

via Extreme weather could become norm around Indian Ocean – environment – 29 November 2013 – New Scientist.

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Tibetan glaciers are shrinking at their summits

Read here, from Nature, about how the glaciers high in the Tibetan Plateau are melting. They are at such altitudes, that such melting should not take place.

The Tibetan glaciers are shrinking. Most of the retreat is thought to be taking place at low elevations, but research now shows that the glaciers may also be losing ice at altitudes up to 6,000 metres.

“The glaciers are virtually being decapitated from the top by a warming climate,” says Kang Shichang, a glaciologist at Chinese Academy of Sciences’ Institute of Tibetan Plateau Research in Beijing.

His team looks at signals left in ice by environmental incidents that changed the chemical composition of the atmosphere. “When air bubbles were trapped in glacial ice, so were chemical compounds” in the air, says Kang.

Among those incidents are nuclear tests that were especially frequent between 1952 and 1963, releasing radioactive compounds such as tritium. “This left a distinctive signature in glaciers around the world,” says Kang.

He got a gloomy feeling when examining ice cores drilled from two Tibetan glaciers at about 6,000 metres, he explained at the 28th Himalayan Karakoram Tibet Workshop and the 6th International Symposium on Tibetan Plateau Joint Conference in Tubingen, Germany, last month.

A core from the Lanong glacier in southern Tibet shows neither the tritium peak associated with nuclear testing nor any trace of radioactive compounds from the Chernobyl nuclear disaster in Ukraine in 1986. This suggests that ice layers laid down on the glacier from the 1950s onwards have melted or sublimated away.

The second ice core, from the Guoqu glacier in central Tibet, has the chemical fingerprints of the nuclear tests and the Galunggung volcanic eruption in Indonesia in 1982, but not the Chernobyl signal. Moreover, the core’s mercury content, which tracks well with global and regional emission trends, ends abruptly in the 1980s. “The glacier has been losing ice in the past three decades,” says Kang.

via Tibetan glaciers are shrinking at their summits : Nature News & Comment.

Global warming ‘hiatus’ unlikely to last

The climate deniers are repeatedly telling us that Global Warming is not happening, and that the temperatures have not changed during the last decade.

Here you can read, from Reuters, about how the Intergovernmental Panel on Climate Change (IPCC) in their soon the be leased report write that the slow down in climate change can be explained by natural variations and volcanic ash.

(Reuters) – A “hiatus” in global warming so far this century is partly caused by natural variations in a chaotic climate and is unlikely to last, a draft United Nations report by leading climate scientists says.

The 127-page draft, and a shorter summary for policymakers that is due for release in Stockholm on September 27 after editing, say factors including a haze of volcanic ash and a cyclical dip in energy emitted from the sun may also have contributed to a slower warming trend.

Explaining what the Intergovernmental Panel on Climate Change (IPCC) draft calls a “hiatus” in warming is vital for governments, which have promised to agree a U.N. deal by 2015 to limit temperature rises, largely by shifting from fossil fuels. France called on Friday for bolder EU cuts in greenhouse gases and said it would halve its own energy consumption by 2050.

The fact that temperatures have risen more slowly in the past 15 years despite rising emissions of greenhouse gases has emboldened skeptics who challenge the evidence for man-made climate change and question the need for urgent action.

But the IPCC draft reports do not project any long-term respite. Instead, they forecast a resumption in the warming trend that is likely to cause ever more heatwaves, droughts, floods and rising sea levels.

“Barring a major volcanic eruption, most 15-year global mean surface temperature trends in the near-term future will be larger than during 1998-2012,” according to the 127-page Technical Summary dated June 7 and obtained by Reuters.

via Global warming ‘hiatus’ unlikely to last: draft U.N. report | Reuters.

Yosemite Rim Fire is taste of things to come – 28 August 2013 – New Scientist

Yosemite Rim Fire is taste of things to come

Here you can read about how huge devastating fires are becoming more common and how Global Warming will lead to more of this kind.

28 August 2013

SAN FRANCISCO is in a state of emergency, its power and water supplies threatened by one of the largest Californian wildfires on record – just 250 kilometres to the east of the city, on the fringes of Yosemite National Park. It is a grim warning of profound changes that may lie ahead. Wildfires have always been a part of life in the US west, but activity is on the rise as climate change takes hold. In Californias Sierra Nevada mountains, the main problem is the earlier onset of spring. “The snow melts earlier, especially at lower elevations,” says Michael Wehner of the Lawrence Berkeley National Laboratory. That gives forests longer to dry out, producing tinderbox conditions by late August. As New Scientist went to press, the Rim Fire had torched over 700 square kilometres and was approaching the Hetch Hetchy reservoir, which provides San Francisco with most of its water and generates hydroelectric power for the citys General Hospital, transit system and airport. It serves as a warning that wildfires can have effects far beyond the area they burn.

via Yosemite Rim Fire is taste of things to come – 28 August 2013 – New Scientist.