The Malaysian Insider :: Features
The Malaysian Insider :: Features |
| World suffered unprecedented climate extremes in past decade Posted: 03 Jul 2013 05:59 AM PDT The world suffered unprecedented climate extremes in the decade to 2010, from heatwaves in Europe and droughts in Australia to floods in Pakistan, against a backdrop of global warming, a United Nations report said today. Every year of the decade except 2008, was among the 10 warmest since records began in the 1850s, with 2010 the hottest, according to the study by the World Meteorological Organization (WMO). The number of daily heat records far outstripped lows. It said many extremes could be explained by natural variations - freak storms and droughts have happened throughout history - but that rising emissions of man-made greenhouse gases also played a role. "Rising concentrations of heat-trapping greenhouse gases are changing our climate, with far-reaching implications for our environment and our oceans, which are absorbing both carbon dioxide and heat," WMO Secretary-General Michel Jarraud said. The study said damaging extremes included Hurricane Katrina in the United States in 2005, Cyclone Nargis in Myanmar in 2008, floods in Pakistan in 2010, droughts in the Amazon basin, Australia and East Africa and a retreat of Arctic sea ice. Deaths from extreme events totalled 370,000 people, up 20 per cent from the 1990s, the Geneva-based WMO said, though the world population also rose sharply over the period, from 5.3 billion in 1990 to 6.9 billion in 2010. The jump in the death toll was caused mainly by a heatwave in Europe in 2003 which killed 66,000 and a heatwave in Russia in 2010 in which 55,000 people died. However, casualties from storms and droughts fell, partly because of better preparedness for disasters. The study said that 44 per cent of nations recorded the highest daily maximum temperature of the past half-century in the decade 2001-10 but only 11 per cent reported a new low. It also said that the decade "continued an extended period of accelerating global warming" with average decadal temperatures 0.21 degree Celsius (0.4 F) warmer than 1991-2000, which was in turn 0.14 C warmer than 1981-1990. Slowing rate of increase? Other reports have found that the rate of temperature rises has slowed this century. "Global mean surface temperatures have not increased strongly since 1998" despite rising greenhouse gas emissions, according to a draft report by the UN's panel of climate scientists due for release in September. Some experts say the apparent rise from the 1990s is magnified because a volcanic eruption in the Philippines in 1991 dimmed sunlight and cut temperatures. The WMO also said it was hard to link any individual extreme events to climate change rather than to natural variability. However, warmer air can hold more moisture, raising risks of downpours - the study said that 2010 was the wettest year since records began. And sea levels have risen about 20 centimetres in the past century, increasing risks of storm surges. One 2004 study, for instance, said that climate change had at least doubled the risks of the European heatwave in 2003. Peter Stott of the UK Met Office who led that study, said scientists were now trying to see if there was a human fingerprint behind other extremes in 2012, such as Superstorm Sandy or drought in Australia. "You can't just take a record-breaking event and say 'that's climate change'," he said. - Reuters, July 3, 2013. |
| Some forms of IVF linked to risk of autism, mental disability Posted: 02 Jul 2013 04:14 PM PDT  Couples who have certain types of fertility treatment have a higher chance of having a child with autism or learning difficulties - although the overall risk is still extremely small, scientists said on Tuesday. The experts said couples should not consider abandoning or avoiding in-vitro-fertilisation (IVF) on the basis of their research findings. The study, conducted by Swedish researchers based in Britain, Sweden and the United States, found children born after IVF treatments for the most severe forms of male infertility were more likely to be diagnosed with autism or an intellectual disability. But the actual numbers were low - children born after one form of IVF treatment had a 0.136 percent risk of having autism - a developmental disorder characterised by poor communication skills - compared with a 0.029 percent risk for children conceived naturally, they said. "The main message ... is a positive one, suggesting that any risk of these disorders is very low, or absent, in comparison to children conceived naturally," said Allan Pacey, who was not involved in the research and is a fertility expert at Sheffield University and Chairman of the British Fertility Society. The study was the largest of its kind and the first to compare all available IVF treatments and the risk of neurodevelopmental disorders in children. The researchers analysed more than 2.5 million birth records from 1982 and 2007 and followed up whether children had been diagnosed with autism or intellectual disability - defined as an intelligence quotient (IQ) score below 70 - until 2009. Of the 2.5 million children, just under 31,000, or 1.2 percent, were born following IVF treatment. Standard IVF treatment involves an egg being fertilised with sperm in a laboratory dish, while intracytoplasmic sperm injection (ICSI) fertility treatments - now used in about half of cases and often recommended for male fertility problems - involve injecting a single sperm directly into an egg. "When we looked at IVF treatments combined, we found there was no overall increased risk for autism, but a small increased risk of intellectual disability," said Sven Sandin of King's College London's Institute of Psychiatry, who co-led the study. "When we separated the different IVF treatments, we found traditional IVF is safe, but that IVF involving ICSI, which is specifically recommended for paternal infertility, is associated with an increased risk of both intellectual disability and autism in children," he told a briefing in London. Rates of autism have been rising rapidly in recent years, to around 1 in 100 children in Europe and as many as 1 in 88 in the United States. Since IVF births are also increasing, some researchers have wondered whether the two might be linked. But Sandin said that while he could not entirely rule out an effect from IVF, it was certainly not the whole answer to why autism rates are going up. "This cannot explain the increased rates we're seeing," he said. "If it does contribute anything, it's a very, very, very small fraction." The study, published in the Journal of the American Medical Association (JAMA), found that children born after IVF treatments with ICSI had a 0.093 percent risk of intellectual disability, compared with a base risk of 0.062 percent. Children born after IVF with ICSI using fresh embryos and surgically extracted sperm - rather than sperm ejaculated naturally - had the higher risk of autism. Avi Reichenberg, who led the study with Sandin at the Institute of Psychiatry and Mount Sinai School of Medicine in New York, said the results showed a link between some IVF treatments a higher risk of developmental disorders in children, but stressed the study did not identify a cause. "The exact mechanism is unclear, but there are a number of risk factors, from selection of IVF procedures, to multiple embryos, and to preterm birth," he told reporters. Pacey said doctors and patients should consider preferentially using standard IVF rather than ICSI wherever possible, and also using ejaculated sperm rather than sperm recovered surgically from the testicles. - Reuters, July 3, 2013. |
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