Tag: global warming

Higher-than-normal sea-level pressure Accelerated melting of two fast-moving outlet glaciers that drain Antarctic ice into the Amundsen Sea Embayment is likely the result, in part, of an increase in sea-surface temperatures in the tropical Pacific Ocean, according to new University of Washington research.Higher-than-normal sea-level pressure north of the Amundsen Sea sets up westerly winds that push surface water away from the glaciers and allow warmer deep water to rise to the surface under the edges of the glaciers, said Eric Steig, a UW professor of Earth and space sciences."This part of Antarctica is affected by what's happening on the rest of the planet, in particular the tropical Pacific," he said.The research involves the Pine Island and Thwaites glaciers on the West Antarctic Ice Sheet, two of the five largest glaciers in Antarctica. Those two glaciers are important because they drain a large portion of the ice sheet.As they melt from below, they also gain speed, draining the ice sheet faster and contributing to sea level rise. Eventually that could lead to global sea level rise of as much as 6 feet, though that would take hundreds to thousands of years, Steig said.NASA scientists recently documented that a section of the ...

Warmer, greener, and less ice An international team of scientists who monitor the rapid changes in the Earth's northern polar region say that the Arctic is entering a new state - one with warmer air and water temperatures, less summer sea ice and snow cover, and a changed ocean chemistry. This shift is also causing changes in the region's life, both on land and in the sea, including less habitat for polar bears and walruses, but increased access to feeding areas for whales.Changes to the Arctic are chronicled annually in the Arctic Report Card, which has been recently released. The report is prepared by an international team of scientists from 14 different countries."This report, by a team of 121 scientists from around the globe, concludes that the Arctic region continues to warm, with less sea ice and greater green vegetation," said Monica Medina, NOAA principal deputy under secretary of commerce for oceans and atmosphere. "With a greener and warmer Arctic, more development is likely. Reports like this one help us to prepare for increasing demands on Arctic resources so that better decisions can be made about how to manage and protect these more valuable and increasingly available resources."Among the 2011 highlights ...

Arctic Report Card The Arctic is entering a new state with warmer air and water temperatures, less summer sea ice and snow cover, and changed ocean chemistry, finds the annual Arctic Report Card. Less habitat for polar bears and walruses but increased access to feeding areas for whales characterizes the new Arctic pattern.The 2012 Arctic Report Card was prepared by an international team of scientists from 14 different countries and issued today by the National Oceanic and Atmospheric Administration, NOAA."This report, by a team of 121 scientists from around the globe, concludes that the Arctic region continues to warm, with less sea ice and greater green vegetation," said Monica Medina, NOAA principal deputy under secretary of commerce for oceans and atmosphere."With a greener and warmer Arctic, more development is likely," Medina said. "Reports like this one help us to prepare for increasing demands on Arctic resources so that better decisions can be made about how to manage and protect these more valuable and increasingly available resources."The Report Card tracks the Arctic atmosphere, sea ice, biology, ocean, land, and Greenland. This year, new sections were added, including greenhouse gases, ozone and ultraviolet radiation, ocean acidification, Arctic Ocean primary productivity, and lake ...

Tracking recent environmental changes Arctic Report Card: Update for 2011 - Tracking recent environmental changes, with 23 essays on different aspects of the environment, by a team of 112 international authors, and independently peer-reviewed by the Arctic Monitoring and Assessment Programme of the Arctic Council.

Environmental observations throughout the Arctic The Arctic Report Card considers a wide range of environmental observations throughout the Arctic, and is updated annually. A major conclusion of the 2011 Report is that there are now a sufficient number of years of data to indicate a shift in the Arctic Ocean system since 2006. This shifted is characterized by the persistent decline in the thickness and summer extent of the sea ice cover, and a warmer, fresher upper ocean.As a result of increased open water area, biological productivity at the base of the marine food chain has increased and sea ice-dependent marine mammals continue to lose habitat. Increases in the greenness of tundra vegetation and permafrost temperatures are linked to warmer land temperatures in coastal regions, often adjacent to the areas of greatest sea ice retreat. A second key point in the 2011 Report is the repeated occurrence of 2010 Arctic winter wind patterns that mark a departure from the norm.These changes resulted in higher than normal temperatures in the Arctic, with record ice sheet mass loss, record low late spring snow cover in Eurasia, shorter lake ice duration, and unusually lower temperatures and snow storms in some low latitude regions. ...

The past decade has been the warmest and ocean acidity levels continue to increase New research providing critical information about how climate change is affecting Australia's Pacific island neighbours and East Timor has been released by the Australian Government's Pacific Climate Change Science Program (PCCSP).The landmark, peer-reviewed publication, Climate Change in the Pacific: Scientific Assessment and New Research, presents the most comprehensive scientific analysis to date of climate change in the Pacific region.Co-editor of the report, the Bureau of Meteorology's Dr Scott Power, said the findings would be presented at an event during the 2011 United Nations Climate Change Conference being held from next week in Durban, South Africa."The research provides clear evidence of how the climate has changed across this region. For example, the past decade has been the warmest on record and ocean acidity levels are continuing to increase in response to rising atmospheric carbon dioxide concentrations," Dr Power said.According to co-editor, CSIRO's Kevin Hennessy, the research indicates future decreases in droughts in most parts of the Pacific and decreases in the frequency of tropical cyclones by the end of the century."We also expect widespread increases in extreme rainfall events, large increases in the incidence of hot days ...

The rate at which marine life needs to relocate is very fast Marine life may need to relocate faster than land species as well as speed up alterations in the timing of major life cycle events. This challenges previous thinking that marine life in the ocean would respond more gradually than species on land because of slower warming in the oceans."Analyses of global temperature found that the rate at which marine life needs to relocate is as fast, or in some places faster, than for land species. This is despite ocean warming being three times slower than land" says paper co-author, Dr Elvira Poloczanska from CSIRO's Climate Adaptation Flagship.Dr Poloczanska said that globally, an increasing number of species are responding to climate change by changing their distributions and the timing of life cycle events such as breeding, spawning and migrations.She said that a one degree change in ocean temperature may mean that marine plants and animals will have to travel hundreds of kilometres to stay in their comfort zones. This can present major problems for marine organisms, particularly those that are unable to move long distances such as corals.This collaborative work was led by Dr Mike Burrows from the Scottish ...

The loss represents 51 per cent of the mussel bed The biodiversity loss caused by climate change will result from a combination of rising temperatures and predation -- and may be more severe than currently predicted, according to a study by University of British Columbia zoologist Christopher Harley.The study, published in the current issue of the journal Science, examined the response of rocky shore barnacles and mussels to the combined effects of warming and predation by sea stars.Harley surveyed the upper and lower temperature limits of barnacles and mussels from the cool west coast of Vancouver Island to the warm shores of the San Juan Islands, where water temperature rose from the relatively cool of the1950s to the much warmer years of 2009 and 2010."Rocky intertidal communities are ideal test-beds for studying the effects of climatic warming," says Christopher Harley, an associate professor of zoology at UBC and author of the study. "Many intertidal organisms, like mussels, already live very close to their thermal tolerance limits, so the impacts can be easily studied."At cooler sites, mussels and rocky shore barnacles were able to live high on the shore, well beyond the range of their predators. However, as temperatures rose, barnacles ...

Even very small changes in the ocean's surface temperature can have an enormous impact elsewhere A new study suggests that the rate of global warming from doubling of atmospheric carbon dioxide may be less than the most dire estimates of some previous studies -- and, in fact, may be less severe than projected by the Intergovernmental Panel on Climate Change report in 2007.Authors of the study, which was funded by the National Science Foundation's Paleoclimate Program and published online this week in the journal Science, say that global warming is real and that increases in atmospheric CO2 will have multiple serious impacts.However, the most Draconian projections of temperature increases from the doubling of CO2 are unlikely."Many previous climate sensitivity studies have looked at the past only from 1850 through today, and not fully integrated paleoclimate date, especially on a global scale," said Andreas Schmittner, an Oregon State University researcher and lead author on the Science article. "When you reconstruct sea and land surface temperatures from the peak of the last Ice Age 21,000 years ago -- which is referred to as the Last Glacial Maximum -- and compare it with climate model simulations of that period, you get a much ...

Sea ice coverage in the Arctic shrank this summer to the second-lowest level ever Sea ice coverage in the Arctic shrank this summer to the second-lowest level ever measured, and an energy and mineral rush is gathering steam in pursuit of nearly a quarter of the world's oil and gas. Meanwhile, a tanker ship has just set the speed record for crossing the Arctic sea in 6 days.At the same time, Vladimir Putin, prime minister of the country with the most Arctic territory, has proclaimed that the Arctic Ocean is going to rival the Suez Canal as a trade route, and that we are upon an era of Arctic industrialization. Even China -- with no Arctic land of its own -- is making significant investments to explore the region, which has a vast expanse of international waters that is for the first time becoming navigable.We should proceed with caution in the Arctic. Home to eleven global "ecoregions," one-fifth of the world's freshwater, and one of the largest contiguous wilderness areas on earth, the Arctic should provide a store of resources for our future generations. But as Bellona Foundation's President, Frederic Hauge, explained at the BSR conference last week, those resources ...