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Southern hemisphere also seeing climate disruption

A poleward shift of the subtropical dry zone may be displacing rainfall in parts of the southern hemisphere.

Rainfall being displaced in critical areas

By Summit Voice

FRISCO — As the northern hemisphere grapples with the impacts of the melting polar ice cap, the southern hemisphere is facing a different climate change issue.

A  poleward expansion of the subtropical dry-zone is probably responsible for a significant decline in autumn rainfall over southeastern Australia and may be affecting seasonal precipitation in other areas.

Since most of the world’s landmass and population is in the northern hemisphere, climate change impacts have been recognized and studied more extensively. Much of the southern hemisphere is open ocean, so there’s less good data to work with, but some research has already  suggested a southward shift in the storm tracks and weather systems during the late 20th century. Continue reading

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Climate: Ocean currents play key role in capturing carbon

Currents are pathways for carbon capture in Southern Ocean

The Southern Ocean is critical carbon sink.

By Summit Voice

SUMMIT COUNTY — Carbon isn’t uniformly absorbed in the Southern Ocean, but is drawn down and locked away from the atmosphere by plunging currents a thousand kilometers wide, according to a team of British and Australian scientists.

Winds, currents and massive whirlpools that carry warm and cold water around the ocean — known as eddies — create localized pathways, or funnels, for carbon to be stored.

 

The Southern Ocean is an important carbon sink in the world. About 40 percent of the annual global CO2 emissions absorbed by the world’s oceans are captured in this region.

“The Southern Ocean is a large window by which the atmosphere connects to the interior of the ocean below. Until now we didn’t know exactly the physical processes of how carbon ends up being stored deep in the ocean,” said Dr. Jean-Baptiste Sallée, of British Antarctic Survey. “Now that we have an improved understanding of the mechanisms for carbon draw-down we are better placed to understand the effects of changing climate and future carbon absorption by the ocean,” he said. Continue reading

Changing ocean salinity a ‘clear fingerprint’ of global warming

Rapid intensification of water cycle expected in the next few decades

Global warming may fuel more intense rain in parts of the world that already wet, and more drought in dry regions. PHOTO BY BOB BERWYN.

By Summit Voice

SUMMIT COUNTY — Even as global warming deniers toot their horns at the discredited Heartland Institute‘s annual anti-science conference, a team of researchers say they’ve detected a pattern of changes in ocean salinity that marks a clear “fingerprint of climate change.”

Analyzing observed ocean salinity changes and the relationship between salinity, rainfall and evaporation in climate models, they determined the water cycle has strengthened by four per cent from 1950-2000. This is twice the response projected by current generation global climate models, according to lead author, Dr. Paul Durack, a post-doctoral fellow at the Lawrence Livermore National Laboratory. Continue reading

Global warming: Marine species under pressure

A 1 degree change in ocean temps could force some species to move hundreds of miles to find suitable habitat

Marine species are facing serious challenges as global temperatures rise.

By Summit Voice

SUMMIT COUNTY — an increasing number of ocean-dwelling species are responding to global warming by changing their distributions and the timing of life cycle events such as breeding, spawning and migrations.

And marine life may need to relocate faster than land species, as well as speed up changes in the timing of major life cycle events — despite the fact that global land surface temperatures are increasing three times as fast as ocean temperatures.

“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,” said Dr Elvira Poloczanska from the Commonwealth Scientific and Industrial Research Organisation’s Climate Adaptation Flagship. Continue reading

Global warming: Can species be saved with relocations?

Conservation biologists are debating whether to relocate species like the golden bowerbird to ensure their survival in the face of climate change. PHOTO COURTESY CSIRO.

Researchers try to spell out a rational plan for so-called assisted colonization in the face of climate change

By Summit Voice

SUMMIT COUNTY — As global warming causes ever-greater disruption to plants and animals, conservation biologists are having serious discussions about how and when to relocate species so they they can survive for the long-term.

If society values them enough, some species threatened by climate disruption could benefit from immediate relocation, especially small and vulnerable populations that need time to grow before risking translocation losses, an international group of researchers wrote in a climate change journal article published this week.

The paper is an effort at creating a pragmatic framework for deciding when, if ever, to move species in the face of climate change. University of Queensland and United States Geological Survey researchers also contributed to the research.

“As our climate changes more rapidly than species can adapt or disperse, natural resource managers increasingly want to know what adaptation options are available to help them conserve biodiversity,” said Dr. Eve McDonald-Madden, of the Commonwealth Scientific and Industrial Research Organization.

Managed relocation of species involves moving plants or animals from an area that is, or will become, untenable because of climate change, to areas where there are more suitable climatic conditions but in which the plants or animals have not occurred previously. It’s sometimes called assisted colonization. Continue reading

Researchers study role of wildfires in climate change

Feedback loop could intensify impacts to carbon cycle

Massive fires have burned across more than 3 million acres in Texas. PHOTO COURTESY TEXAS FOREST SERVICE. Click on the image for a gallery of photos from this year's wildfires.

By Summit Voice

SUMMIT COUNTY — Scientists speaking at an international symposium in Australia this week said wildfires are likely play an increasingly important role in climate change, but that more study is needed to determine exactly what those effects will be.

Fires are one of nature’s primary carbon-cycling mechanisms, said Dr. Melita Keywood, a researcher with Australia’s national research agency, the Commonwealth Scientific and Industrial Research Organisation.

A press release from CSIRO highlighted some of the questions Keywood raised in a recent presentation at a gathering of geophysicists. Continue reading

Global warming: Venice storm surges may decrease

Storm surges that can damage historic Venice structures predicted to become less frequent under some climate change scenarios. PHOTO BY BOB BERWYN.

Shifting storm patterns may have implications for preservation of historic city

By Summit Voice

SUMMIT COUNTY — Although sea-level rise caused by global warming is considered a serious threat to Venice, new research suggests that storm surges in the northern Adriatic Sea may decrease in frequency by 30 percent in the next few decades, leaving the historic city less vulnerable to damaging floods.

The storm surges that push water into the maze of canals are generated by the passage of deep low-pressure systems, which cause sea level pressure gradients and strong, south-easterly Sirocco winds along the Adriatic Sea. These forces combine to push water into the northern end of the basin where Venice is located.

Some climate change models show that storm will shift in the coming decades. The climatologists who published the recent study said their work shows changes in extreme tidal levels under climate change must be considered on a location-by-location basis in spite of the projected increase in global sea level. Continue reading

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