18 November 2015, The Conversation, Shrinking Antarctic glaciers could make Adélie penguins unlikely winners of climate change. Penguin numbers exploded in East Antarctica at the end of the last ice age, according to research published today in BMC Evolutionary Biology. Despite their image as cold-loving creatures, the increase in Adélie penguin numbers seems to be closely linked to shrinking glaciers, raising the possibility the these penguins could be winners from current climate change. Adélie penguins are one of only two penguin species that live on the Antarctic continent. Their cousins, emperor penguins, may be the movie stars, but it is the Adélies that are the bigger players in the Southern Ocean. They outnumber emperors by more than ten to one, with a population of over 7.5 million breeding adults and counting. Given the abundance of Adélie penguins and their crucial role in Southern Ocean ecosystems, there has been a great deal of interest in understanding how the species is likely to respond to future climate change. Sensitivity to sea ice Breeding colonies have been monitored for decades to determine the effects of a changing environment on the penguins. A common finding of many of these studies is that Adélies are highly sensitive to sea ice conditions. Unlike emperor penguins, Adélies do not nest on the sea ice, but they must cross it to reach their nests on land. As everyone knows, penguins are not the most efficient walkers, and in years with a lot of sea ice their journeys to and from the ocean to feed their chicks can become lengthy. With a longer wait between meals chicks are less likely to survive. In an extreme case, extensive sea ice at one breeding colony had a devastating impact in 2014, and not a single chick survived. Read More here
Category Archives: Antarctica
11 November 2015, Climate News Network, West Antarctic ice cascades towards crisis. Scientists warn that continued ocean warming will lead to ice loss in the Amundsen Sea region that could raise sea levels by three metres. It wouldn’t take much to precipitate the complete collapse of the West Antarctic ice sheet, according to new research. Just a few more decades of ocean warming would be enough to destabilise the relatively small region of ice by the Amundsen Sea − starting a cascade of slipping and sliding that would tip enough ice into the ocean to raise sea levels by three metres. The loss of ice would continue for centuries. Two scientists at the Potsdam Institute for Climate Impact Research (PIK) in Germany report in the Proceedings of the National Academy of Sciences that they wanted to take a look at the long-term future of the mass of south polar ice that has been worrying researchers for decades. Planetary temperatures The West Antarctic ice sheet has already been pronounced as being at the point of no return. Scientists have calculated that, were the world ever to burn all its fossil fuels, thus increasing levels of atmospheric carbon dioxide and stoking up planetary temperatures, that would be enough to melt the entire Antarctic continent and raise sea levels by 60 metres. But one of those studies focused on what is happening now; the second looked thousands of years ahead. Read More here
10 November 2015, Science Daily, Geophysics could slow Antarctic ice retreat. Gravitational effects, variations in Earth structure could damp rise in global sea levels. The anticipated melting of the massive West Antarctic Ice Sheet could be slowed by two big factors that are largely overlooked in current computer models, according to a new study. The findings, published online in Nature Communications, suggest that the impact on global sea levels from the retreating ice sheet could be less drastic — or at least more gradual — than recent computer simulations have indicated. Over the past year, numerous studies have warned that parts of the West Antarctic Ice Sheet are on the verge of a runaway retreat. Just last week a high-profile research paper forecast that this could lead eventually to a rise in global sea levels of as much as three metres. The authors of the new Nature Communications paper, however, focus on two geophysical elements that they say aren’t adequately reflected in computer simulations for this region: the surprisingly powerful gravitational pull of the immense ice sheet on surrounding water, and the unusually fluid nature of the mantle beneath the bedrock that the ice sits on. “The fate of the polar ice sheets in a warming world is a major concern for policy makers — and attention is rightly focused on the importance of restraining CO2 emissions and preparing for rising sea levels,” says lead author Natalya Gomez, an assistant professor of Earth and Planetary Sciences at McGill University in Montreal. “But our study shows that for Antarctica, in particular, computer models also need to take into account how gravitational effects and variations in Earth structure could affect the pace of future ice-sheet loss.” Read More here
6 November 2015, Renew Economy, Big step finally taken towards making your fridge and air-con climate friendly. It’s hard to imagine the rhetoric soaring to greater heights. “A great signal for Paris”,”a much needed shot in the arm for climate action”, “provide an example of successful international cooperation”, “provide critical momentum for the climate negotiations”, “a strong signal to the UNFCCC to adopt a robust agreement at COP 21”, “boosting global cooperation ahead of Paris to benefit the planet”… Expectations were almost palpable. “A singular opportunity for countries to take action on climate”,”would set the stage for an ambitious and durable global climate agreement”, “lay the foundation for a global agreement in Paris that will protect generations to come”, “demonstrate that governments around the world have the political will to take bold action to avert a climate catastrophe”, “potentially catalyse far-reaching action at Paris”… Stirring stuff indeed, but who’d have guessed what all the fuss was about? You’d be forgiven for missing the muted clamour anticipating a long overdue agreement on the need to respond to the science calling for international action on the world’s most powerful and rapidly growing greenhouse gases. In a much anticipated gathering of the global community of nations in Dubai over the past week, intense negotiations have been taking place. The ultimate goal of the talks, which began in 2008, is to amend the Montreal Protocol to formally address the need to address the alarmingly rapid rise of the hydrofluorocarbons, or HFCs, highly potent greenhouse gases used across the refrigeration and air conditioning industries. A recent NASA study reported to the meeting also confirmed that contrary to previous understanding HFCs do have a small yet significant effect on ozone depletion, a point poignantly underscored by the appearance of the third largest Ozone hole this year. Read More here