Tag: Nature Reports Climate Change

  • Confronting the biodiversity crisis

    Confronting the biodiversity crisis

    In 2002, the world’s governments agreed to significantly slow the rate of biodiversity loss by 2010. Time is almost up, and by most accounts they’ve failed. Now that climate change is emerging as one of biodiversity’s greatest threats, scientists are proposing new ways to tackle the crisis. Hannah Hoag reports.

    Barcoding life

    In July 2009, for the fourth year in a row, a swarm of biologists fanned out across the tundra near Churchill, Manitoba, in northern Canada. They plucked fragments of plants and animals — feathers and fur, mayflies and moths — from land, lakes, rivers and ocean. At the lab, the specimens were ground up and identified using short stretches of DNA — a unique barcode for every species. So far, the team — led by Paul Hebert, an evolutionary biologist at the University of Guelph in Canada, who invented DNA barcoding (Proc. R. Soc. B 270, 313–321; 2003) to speed up the process of taxonomy — has identified more than 4,000 species from its northern expeditions, including parasitic wasps that have been observed across North America but were previously overlooked in the Canadian Arctic.

    “The first business of conservation is telling species apart,” says Hebert. Before barcoding, biological specimens were identified on the basis of morphology, behaviour and genetics. The technique will offer a “quantum jump” in the rate that species are registered, says Hebert. What once took months can now take a few hours. It also gives biodiversity a boost: barcoding has repeatedly shown that one species is, in fact, three, or ten (Evol. Biol. 7, 121; 2007).

     

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  • The missing greenhouse gas

    Growth of the electronics industry will boost emissions of a ‘hidden’ — but extremely potent — greenhouse gas.

    Our insatiable appetite for gadgets — mobile phones, MP3 players and flat-screen TVs — may be adding a hidden greenhouse gas to the Earth’s atmosphere. Countries that ratified the Kyoto Protocol committed to reducing their emissions of carbon dioxide and five other heat-trapping gases: methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. But these aren’t the only climate-altering chemicals being produced by human activity. In the 13 years since the Protocol was first drawn up, scientists have discovered that other gases, such as nitrogen trifluoride (NF3), could become an increasing part of the climate problem.

    :: Read more in Nature Reports: Climate Change ::

  • Rapid Ice Retreat Threatens Arctic Interior

    Rapid Ice Retreat Threatens Arctic Interior

    Nature Reports: Climate Change

    The rapid decline of sea ice could accelerate inland warming over the Arctic region, radically transforming the landscape.

    One of the Northern Hemisphere’s natural cycles is the expansion and contraction of the floating Arctic ice cap. Typically, sea ice decreases during the Arctic summer, reaching a low in September, before recovering as temperatures drop in winter. From as far back as satellite measurements began in 1978 until 2000, the average sea-ice extent, or the area of ocean covered by at least 15 per cent ice, has routinely hovered around 7 million square kilometres during the summer minimum.

    But in 2002, scientists noticed a sharp drop in the region’s minimum ice coverage. By September 2007, the area covered by ice had been whittled down to a startling 4.3 million square kilometres — 40 per cent smaller than in the 1980s. Scientists say the retreat witnessed last year was drastic, unexpected and more than 20 per cent below the previous record minimum.

    Not only will the loss affect the marine ecosystem and its dependents, from indigenous communities to marine mammals that rely on the ice for hunting and travel; it stands to alter the Arctic landscape much further afield. According to a new study in the 13 June issue of Geophysical Research Letters, the rapid retreat of Arctic sea ice could accelerate warming 1,500 kilometres inland in northern Alaska, Canada and Russia. During rapid ice retreat, the rate of inland warming could be more than three times that previously predicted from global climate models.

    :: Read more in Nature Reports: Climate Change ::