‘Evil twin of global warming’ threatens world's oceans

Scientists have warned that ocean acidification, which is dubbed the ‘evil twin of global warming’, caused by a rise in human emissions of carbon dioxide (CO2), threatens the world’s oceans.

“Ocean conditions are already more extreme than those experienced by marine organisms and ecosystems for millions of years,” researchers said in the latest issue of the journal Trends in Ecology and Evolution (TREE). “This emphasises the urgent need to adopt policies that drastically reduce CO2 emissions,” they added. Ocean acidification, which the researchers call the ‘evil twin of global warming’, is caused when the CO2 emitted by human activity, mainly burning fossil fuels, dissolves into the oceans. It is happening independently of, but in combination with, global warming.

“Evidence gathered by scientists around the world over the last few years suggests that ocean acidification could represent an equal -or perhaps even greater threat -to the biology of our planet than global warming,” said co-author Professor Ove Hoegh-Guldberg of the ARC Centre of Excellence for Coral Reef Studies and The University of Queensland. More than 30 percent of the CO2 released from burning fossil fuels, cement production, deforestation and other human activities goes straight into the oceans, turning them gradually more acidic.

“The resulting acidification will impact many forms of sea life, especially organisms whose shells or skeletons are made from calcium carbonate, like corals and shellfish. It may interfere with the reproduction of plankton species which are a vital part of the food web on which fish and all other sea life depend,” said Professor Hoegh-Guldberg.

The scientists say there is now persuasive evidence that mass extinctions in past Earth history, like the “Great Dying” of 251 million years ago and another wipeout 55 million years ago, were accompanied by ocean acidification, which may have delivered the deathblow to many species that were unable to cope with it.

According to lead author, Dr. Carles Pelejero, from ICREA and the Marine Science Institute of CSIC in Barcelona, Spain, “These past periods can serve as great lessons of what we can expect in the future, if we continue to push the acidity the ocean even further.” “Given the impacts we see in the fossil record, there is no question about the need to immediately reduce the rate at which we are emitting carbon dioxide in the atmosphere,” he added.

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ISRO exploring low-cost access to space

The Indian Space Research Organisation (ISRO) is exploring low-cost access to space and has begun taking various measures, ISRO Chairman K. Radhakrishnan has said.

He was delivering the inaugural lecture under the Popular Lecture Series organised by the Indian Institute of Science Alumni Association Science Forum here on Saturday.

Dr. Radhakrishnan said that by 2012, low-cost access to space would be made possible by ISRO's GSLV Mk3 with indigenous cryogenic technology. “Right now, the cost per kg is $20,000. With GSLV Mk3, the cost can be reduced by half,” he added.

India had been applauded for its shoestring budget for space programmes, which was three per cent of NASA's budget, 12 per cent of Europe and one-third of China's, he said. He stressed the need to develop innovative technologies for low-cost access to space. Dr. Radhakrishnan said that the human space flight was the next logical step for India. “We have a human space flight programme and ISRO is going to put two Indians in an orbit around the Earth,” he said.

Studies on

“There is a pre-project which is going on to study some critical technologies. A project report regarding the same has been sent to the government for approval.”

The manned mission programme envisaged development of a fully autonomous orbital vehicle carrying two or three crewmembers to over 300 km in the Earth's orbit. Dr. Radhakrishnan said that ISRO was getting ready to launch GSLV-D3 with indigenous cryogenic technology this month. “Preparations are on. The final reviews are also taking place.”

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On the trail of the Olive Ridley

One Sunday morning in mid-March, hundreds of turtles arrived at the Rushikulya beach in Orissa. Every wave brought in more and more females; Olive Ridley Turtles continued to arrive wave after wave to nest on the beach.

Arribada, a Spanish word meaning the arrival, is a phenomenon which is peculiar to the Ridley turtles ( Lepidochelys ). This is observed in two different nesting beaches in India, along the coast of Orissa.

For the 2010 nesting season, the first arribada took place in the Gahirmatha beach in the second week of February. This beach is a protected area under the Bhitarkanika Wildlife Sanctuary. The second took place in Rushikulya between March 15 and the early hours of March 21. Interestingly, this year there was a third mass nesting which began on the evening of March 20. It is estimated that around one lakh turtles nested along the Rushikulya coast between March 15 and 21, this year. The Orissa Forest Department had made arrangements to ensure the safety of the nests, protecting them from predators by fencing the beach along the forest side of the beach and placing forest guards to deter predators during the night. The eggs are expected to hatch by the end of April, flooding the beach with baby turtles that will make their way to the sea.

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Solar desalination system developed by BARC

The Bhabha Atomic Research Centre (BARC) here has developed a desalination system based on solar heat and light.

Solar energy-based small and community level Reverse Osmosis (RO) unit has been developed for producing safe drinking water, Saly T. Panicker of the Desalination Division of BARC said.

In the RO unit, the feed water is passed through the membrane with the help of a DC (Direct Current) pump connected to the Photovoltaic (PV) panels without any batteries.

The unit can be operated for 9 to 10 hours on a sunny day, which can cater to the drinking and cooking requirements of three to four families at an average rate of five litres per person per day, Panicker said.

“It contains a filter cartridge and a spirally wound RO membrane element,” he said, adding there was no significant variation in the rate of power production from the PV panels.

“Thus, the pump is able to maintain its pace, keeping the rate of drinking water production constant,” Mr. Panicker, who has developed the technology along with scientists K. L. Thalor and P. K. Tiwari, said.

Explaining the system, he said the RO is a pressure driven process, where pure water is continuously drawn from salty water through a semi-permeable membrane.

Highlighting the importance of solar-powered system which will be useful especially in remote areas, Mr. Panicker said integrating desalination with renewable energy sources is also important for addressing the issues related to adverse impacts of climate change.

The source of solar energy is inexhaustible and is free. Also, no harmful gases like nitrogen oxide, mercury, carbon dioxide or sulphur dioxide are emitted, he said.

As for cost, he said, “with the improvement in PV efficiencies and the subsidies available, the solar-based desalination system would become very cost effective.”

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