,
http://cheapjordansstock.com
Assembling a detailed timeline surrounding the Antarctic ice sheet’s inception around 34 million years ago, scientists have identified a carbon dioxide “danger zone” for the ice sheet’s demise.
Based on CO2 levels when the ice sheet formed,
cheap wholesale jordans
, the researchers report that Antarctica’s ice will be “dramatically” more vulnerable to melting once CO2 surpasses 600 parts per million?in the atmosphere. Concentrations of the greenhouse gas reached 400 ppm last year,
cheap jordans
, well above its 280 ppm preindustrial level.
“With present-day emission rates,
cheap real jordans
, it’s expected that we’ll reach 600 ppm before the end of this century,” says study coauthor Simone Galeotti,
cheap jordans online
, a paleoclimate scientist at the University of Urbino in Italy. The ice sheet stockpiles enough water to raise sea levels by around 60 meters and reshape Earth’s coastlines.
The new work, published online March 10 in Science,
cheap retro jordans
, provides the best estimate yet for the CO2 threshold that fostered the Antarctic ice sheet’s appearance,
cheap jordans for sale
, Galeotti says. Scientists previously traced the ice sheet’s beginnings using indirect measurements such as falling sea levels. Those methods aren’t definitive,
cheap air jordans
, however.
Galeotti and colleagues studied a roughly 900-meter-long ocean sediment core drilled in 1999 off the coast of East Antarctica. The core provided a detailed record of the Antarctic ice sheet’s size from around 34 million to 31 million years ago. As the ice sheet expanded,

https://www.gauthampda...re-modules#comment-399153

http://www.angelrockpr...amp;PID=12593283#12593283

http://ezyrecon.com/files/