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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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Global warming will shift South Pacific rain band

A 2004 NASA satellite image shows a volcano erupting on Vanuatu, in the South Pacific.

Island nations can expect to see more drought and flooding

By Summit Voice

SUMMIT COUNTY — Already under the gun from rising sea levels, some South Pacific island nations could also be swamped by more extreme floods and hit by drought as global temperatures rise in response to more heat-trapping greenhouse gases in the atmosphere.

The international study, led by CSIRO oceanographer Dr. Wenju Cai, examines how the South Pacific rain band will respond to greenhouse warming.

The South Pacific rain band is largest and most persistent of the Southern Hemisphere, spanning the Pacific from south of the Equator, south-eastward to French Polynesia. Occasionally, the rain band moves northwards towards the Equator by ip to 1,000 kilometers, inducing extreme climate events. Continue reading

Global warming drives dramatic changes in ocean currents

Changes in global wind patterns have pushed the East Australian Current southward and warmed temperatures in the ocean off Tasmania by several degrees in the past few decades. (NASA SATELLITE IMAGE)

Researchers see a global pattern of emerging  hotspots as currents migrate toward poles

By Summit Voice

SUMMIT COUNTY — An ever-expanding network of sensitive measuring devices, including ocean buoys is enabling researchers to get a better handle on the magnitude and scale of global climate change, including a patterned emergence of ocean hotspots alongside currents that wash the east coast of the major continents.

The warming in those areas far exceeds the average rate of ocean warming, according to research published the journal Nature Climate Change this week.

“We would expect natural change in the oceans over decades or centuries but change with such elevated sea surface temperatures in a growing number of locations and in a synchronised manner was definitely not expected,” said  Dr. Wenju Cai, of the Commonwealth Scientific and Industrial Research Organisation. 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

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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