Climate

Arctic Warming Continuing, Approaching Tipping Point?
February 14, 2012 07:20 AM - Jeremy Hance, MONGABAY.COM

Last year the Arctic, which is warming faster than anywhere else on Earth due to global climate change, experienced its warmest twelve months yet. According to recent data by NASA, average Arctic temperatures in 2011 were 2.28 degrees Celsius (4.1 degrees Fahrenheit) above those recorded from 1951-1980. As the Arctic warms, imperiling its biodiversity and indigenous people, researchers are increasingly concerned that the region will hit climatic tipping points that could severely impact the rest of the world. A recent commentary in Nature Climate Change highlighted a number of tipping points that keep scientists awake at night.

Himalayan Ice melt less than thought
February 10, 2012 07:04 AM - Miguel Llanos, msnbc.com

Estimates from satellite monitoring suggest the melt rate from the Himalayas and other high-altitude Asian mountains in recent years was much less than what scientists on the ground had estimated, but those monitoring the satellite data warn not to jump to the skeptical conclusion. The region's ice melt from 2003-2010 was estimated at 4 billion tons a year, far less than earlier estimates of around 50 billion tons, according to the study published Wednesday in the peer-reviewed journal Nature.

Marguerite Bay Glaciation
February 9, 2012 02:24 PM - Editor, ENN

Marguerite Bay or Margaret Bay is an extensive bay on the west side of the Antarctic Peninsula, which is bounded on the north by Adelaide Island and on the south by Wordie Ice Shelf, George VI Sound and Alexander Island. A new paper reports glacial geological data that provide evidence for the timing of ice-sheet retreat and thinning at the end of the last glaciation (~10,000 years ago) in Marguerite Bay. The length of time that rock outcrops have been exposed was dated which allow dating of the thinning of the ice sheet, and the record from seabed sediments. This then allows the determination of how the ice sheet retreated across the continental shelf. The dating shows a surprising pattern. About 9,600 years ago, the ice in Marguerite Bay appears to have thinned very quickly indeed, an observation that turns out to be consistent with several other datasets from the same area (ice-shelf collapse histories, raised beaches and lake sediment cores).

Tree Rings and Volcanic Eruptions
February 8, 2012 11:28 AM - Andy Soos, ENN

Counting the number of tree rings and observing the relative growth for each ting can give an age for when something happened. However, it may not be that simple. Some climate cooling caused by past volcanic eruptions may not be evident in tree-ring reconstructions of temperature change, because large enough temperature drops lead to greatly shortened or even absent growing seasons, according to climate researchers who compared tree-ring temperature reconstructions with model simulations of past temperature changes.

Rising ocean acidity worst for Caribbean and Pacific
February 7, 2012 03:35 PM - Lisbeth Fog, SciDevNet

The current trend of increasing ocean acidification, which threatens fisheries around the world, is driven mainly by man-made changes and is higher even than that seen at the end of the last ice age, some 11,000 year ago, a study has said. Much of the carbon released by human activity ends up in the oceans, increasing their acidity and reducing the growth of corals and molluscs, which in turn may affect fisheries and aquaculture.

Dune Flows
February 7, 2012 10:00 AM - Andy Soos, ENN

Sand dunes flow over the land subject to the winds like ocean waves or rivers. What makes them move? What makes them start or stop? In a study at the White Sands National Monument in New Mexico, University of Pennsylvania researchers have uncovered a unifying mechanism to explain the beautiful dune patterns that occur. The findings may also hold implications for identifying when dune landscapes like those in Nebraska's Sand Hills may reach a tipping point under climate change, going from valuable grazing land to barren desert.

Once, men abused slaves. Now we abuse fossil fuels
February 6, 2012 04:51 PM - Andy Gryce, Population Matters

Pointing out the similarities (and differences) between slavery and the use of fossil fuels can help us engage with climate change in a new way, says Jean-François Mouhot, visiting researcher at Georgetown University, USA. In 2005, while teaching history at a French university, I was struck by the general disbelief among students that rational and sensitive human beings could ever hold others in bondage. Slavery was so obviously evil that slave-holders could only have been barbarians. My students could not entertain the idea that some slave-owners could have been genuinely blind to the harm they were doing. At the same time, I was reading a book on climate change which noted how today's machinery – almost exclusively powered by fossil fuels like coal and oil – does the same work that used to be done by slaves and servants. "Energy slaves" now do our laundry, cook our food, transport us, entertain us, and do most of the hard work needed for our survival.

The Super Green Bowl
February 3, 2012 07:20 AM - Kara Scharwath, Triple Pundit

For the past 18 years, the NFL has been working to decrease the environmental footprint of the largest annual sporting event in the U.S. – the Super Bowl. Two years ago, we wrote about several initiatives aimed at reducing the events’ impacts. Last year, we covered how Super Bowl XLV was slated to be the greenest NFL championship game in history. This year, the NFL is trying to outdo itself yet again by working with the Green Mountain Energy Company and the Indianapolis community to make Super Bowl XLVI the greenest yet. I talked with Jack Groh, Director of the NFL’s Environmental Program, to get the details on this year’s efforts.

Carbon Source or Carbon Sink: Greenhouse Gases in the Tropics
February 2, 2012 09:47 AM - David A Gabel, ENN

The lush vegetation wrapping the center of the globe is one of the most important features for regulating a stable climate in the world. Much excess CO2 emissions from industrialized regions find their way to the equator to be absorbed by abundant CO2-consuming plant life. However, as large tracts of tropical rainforest are cut down in the Amazon, Congo, and Southeast Asia, worries have grown that this vital region may turn from a carbon sink to a carbon source. Those worries can be put at ease somewhat thanks to a recent study from the Woods Hole Research Center (WHRC). Their report suggests that carbon storage of forests, shrublands, and savannas in the tropics are 21 percent higher than previously believed.

Early Ice Ages
February 1, 2012 02:04 PM - Andy Soos, ENN

New research led by scientists from Oxford University and Exeter University has shown that the invasion of the land by plants in the Ordovician Period (488-443 million years ago) cooled the climate and may have triggered a series of ice ages. During this period sea levels are very high and at the end of the period there was a mass extinction event. At the beginning of the period, around 480 million years ago, the climate was very hot due to high levels of CO2, which gave a strong greenhouse effect. The marine waters are assumed to have been around 45°C, which restricted the diversification of complex multi-cellular organisms. But over time, the climate become cooler, and around 460 million years ago, the ocean temperatures became comparable to those of present day equatorial waters. The dramatic cooling of the planet between 300 and 200 million years ago was also the result of the evolution of large plants with large rooting systems that caused huge changes in both of these processes. In the current results it was shown that the appearance of the first land plants had a similar effect and much earlier in time.

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