Friday, April 28, 2017

Antarctica: Scientists stunned by huge discovery in Antarctica, somethin...

Half of All Species Are on the Move—And We're Feeling It


[National Geographic] The shrubs probably responded first. In the 19th century, alder and flowering willows in the Alaskan Arctic stood no taller than a small child—just a little over three feet. But as temperatures warmed with fossil fuel emissions, and growing seasons lengthened, the shrubs multiplied and prospered. Today many stand over six feet.
Bigger shrubs drew moose, which rarely crossed the Brooks Range before the 20th century. Now these spindly-legged beasts lumber along Arctic river corridors, wherever the vegetation is tall enough to poke through the deep snow. They were followed by snowshoe hares, which also browse on shrubs.
Today moose and hares have become part of the subsistence diet for indigenous hunters in northern Alaska, as melting sea ice makes traditional foods like seals harder to chase.
That's just one of thousands of ways in which human-caused climate change is altering life  for plants and animals, and in the process having direct and sometimes profound impacts on humans. As the planet warms, species are shifting where, when, and how they thrive. They are moving up slopes and toward the poles. That is already altering what people can eat; sparking new disease risks; upending key industries; and changing how entire cultures use the land and sea.
"We're talking about a redistribution of the entire planet's species," says Gretta Pecl, lead author of a new study in Science that examined the implications of wildlife on the move.

The changes already are quite dramatic. Malaria, for example, now appears higher up mountain slopes in Colombia and Ethiopia, as rising thermostats make way for mosquitoes at higher elevations. Leishmaniasis, a sometimes-fatal, once primarily tropical affliction, has moved into northern Texas as the sandflies that host the disease-causing parasite head north.
Agriculture is feeling the effects too, as crop pests expand their range. Diamondback moths, which ravage the cabbages, kale, and cauliflower grown by poor urban farmers, are spreading in South Africa. In Latin America, coffee plant funguses and pests are appearing in new areas, threatening a key industry. The same is happening to French olives, wine grapes, and lavender. And in the United States, scientists suspect climate change has promoted the increasingly rapid spread of Johnson grass, a highly invasive weed that reduces yields for legumes, corn, sorghum, and soybean. Read More

Scientists keep increasing their projections for how much the oceans will rise this century

[Spokesman Review] A report by a leading research body monitoring the Arctic has found that previous projections of global sea level rise for the end of the century could be too low, thanks in part to the pace of ice loss of Arctic glaciers and the vast ice sheet of Greenland.
It’s just the latest in a string of cases in which scientists have published numbers that suggest a grimmer picture than the one presented in 2013 by an influential United Nations body, the Intergovernmental Panel on Climate Change.
The new Snow, Water, Ice and Permafrost in the Arctic report presents minimum estimates for global sea level rise by the end of the century, but not a maximum. This reflects the fact that scientists keep uncovering new insights that force them to increase their sea level estimates further, said William Colgan, a glaciologist with the Geological Survey of Denmark and Greenland, who contributed to the sea level rise section.
“Because of emerging processes, especially related to the Greenland ice sheet and the Antarctic ice sheet, it now looks like the uncertainties are all biased positive,” Colgan said.
The assessment found that under a relatively moderate global warming scenario – one that slightly exceeds the temperature targets contained in the Paris climate agreement – seas could be expected to rise “at least” 52 centimeters, or 1.7 feet, by the year 2100. Under a more extreme, “business as usual” warming scenario, meanwhile, the minimum rise would be 74 centimeters, or 2.4 feet.
The new findings were published Tuesday as part of a broader overview report by the Arctic Monitoring and Assessment Program, a working group of the intergovernmental Arctic Council, which unites eight Arctic nations, including the United States, and six organizations representing the indigenous peoples of the Arctic.
It is the work of 90 scientists and 28 peer reviewers and is expected to be presented in Fairbanks, Alaska, next month at the next summit of Arctic political leaders.
The report bluntly contrasts its sea level findings with a previous 2013 report from the U.N. Intergovernmental Panel on Climate Change, which had put the “likely” low end sea level rise number for these two scenarios at 32 centimeters (about 1 foot) and 45 centimeters (1.5 feet) for the period between 2081 and 2100. That global body – whose high end sea level rise number for the year 2100 was just shy of one meter, or 3.2 feet – has often seen its assertions on sea level rise faulted by scientists for being too conservative. Read More

New visualizations show worst-case scenario for sea levels by 2100

[USA Today] The U.S. Naval Academy, JFK Airport, the Jefferson Memorial and President Donald Trump's Mar-A-Lago estate all could be underwater by the year 2100.
That's the doomsday prediction of a worst-case scenario of sea levels rising out of control by the end of the century, according to the National Oceanic and Atmospheric Administration and Climate Central, a non-profit environmental research group.
NOAA's report in January included an extreme sea-level rise forecast of 10 to 12 feet of sea-level rise by 2100 around the U.S., compared to the previous estimate of about 8 feet.
Climate Central then created images that showed what such extreme water rises would look like.
In New York City, for instance, an average high tide would be 2 feet higher than Hurricane Sandy’s flood level, covering an area inhabited by more than 800,000 residents.
Florida would be the most affected state by total population, followed by New York, California, Virginia, and New Jersey. Hawaii and Louisiana would rank second and third by percentage of population affected, after Florida, also first in this category
“It’s a scenario that we hope never occurs,” said William Sweet, a NOAA oceanographer who coordinated production of the agency’s January report, “It’s probably very unlikely, but definitely possible.”
The seas have risen and fallen before. What's new is the enormity of coastal development that will need to be protected, moved or abandoned.
Sea level has risen nearly 8 inches worldwide since 1880 but, unlike water in a bathtub, it doesn't rise evenly. In the past 100 years, it has climbed about a foot or more in some U.S. cities because of ocean currents and land subsidence — 11 inches in New York and Boston, 12 in Charleston, 16 in Atlantic City, 18 in Norfolk and 25 in Galveston, Texas, according to NOAA. Read More