A new study, "Acceleration of snow melt in an Antarctic Peninsula ice core during the twentieth century," published in the journal, Nature Geoscience, indicates that the rate of the summer Antarctic ice melt has increased by nearly ten times between the 15th and 20th Centuries. That increased melting has been caused by a progressively warmer environment. The truly disturbing finding, however, is that most of the increased ice melt in Antarctica has occurred in the last 50-60 years. Let me highlight the relevant portion of the Abstract (to see the full article you need to subscribe to Nature Geoscience):
The warming has occurred in progressive phases since about AD 1460, but intensification of melt is nonlinear, and has largely occurred since the mid-twentieth century. Summer melting is now at a level that is unprecedented over the past 1,000 years. We conclude that ice on the Antarctic Peninsula is now particularly susceptible to rapid increases in melting and loss in response to relatively small increases in mean temperature.
Most of us are aware of the dramatic loss of sea ice in the Arctic, which has been well documented and linked to a dramatic rise in rise in temperatures there, but Antarctic has been undergoing its own rapid rise in temperature, one that had been previously underestimated, but which we now know occurred as a rate twice as fast as previously believed according to a prior study published in Nature Geoscience in December 2012.
The record reveals a linear increase in annual temperature between 1958 and 2010 by 2.4±1.2 °C, establishing central West Antarctica as one of the fastest-warming regions globally. We confirm previous reports of West Antarctic warming, in annual average and in austral spring and winter, but find substantially larger temperature increases. In contrast to previous studies, we report statistically significant warming during austral summer, particularly in December–January, the peak of the melting season.
To put that in layperson's terms, here is an excerpt from an article published in Forbes regarding that study:
West Antarctic temperatures are rising twice as fast as previously estimated, according to new research published in Nature Geoscience. Temperature records compiled from the Byrd Research Station show that since 1958, the region has seen average temperature increases of 2.4 degrees Celsius (4.3 degrees Fahrenheit). That poses a danger of causing sea levels to rise even faster than previously predicted.The more recent study published online yesterday confirms the intensification of the increased ice melt and and makes a connection with rising temperatures in the Antarctic:
Summer ice is melting at a faster rate in the Antarctic peninsula than at any time in the last 1,000 years, new research has shown.Call climate change a hoax created by Gerge Soros, Moveon.org, Michael Moore and Al Gore all you want, Senator Inhofe, but every day the facts keep piling up that our climate is undergoing radical change over the last half-century at a rate which literally boggles the mind. Changes that correlate with, and which 97% of climate scientists agree are caused by, the rapid rise in Carbon Dioxide and other greenhouse gases emitted into our atmosphere.
The evidence comes from a 364-metre ice core containing a record of freezing and melting over the previous millennium. [...]
Lead researcher Dr Nerilie Abram, from the Australian National University and British Antarctic Survey (BAS), said: "We found that the coolest conditions on the Antarctic peninsula and the lowest amount of summer melt occurred around 600 years ago. [...]
"Summer melting at the ice core site today is now at a level that is higher than at any other time over the last 1,000 years. And while temperatures at this site increased gradually in phases over many hundreds of years, most of the intensification of melting has happened since the mid-20th century."
Levels of ice melt on the Antarctic peninsula were especially sensitive to rising temperature during the last century, he said.
"What that means is that the Antarctic peninsula has warmed to a level where even small increases in temperature can now lead to a big increase in summer melt," Abram added.
Carbon dioxide levels measured at at Mauna Loa observatory in Hawaii jumped by 2.67 parts per million (ppm) in 2012 to 395ppm, said Pieter Tans, who leads the greenhouse gas measurement team for the US National Oceanic and Atmospheric Administration (NOAA). The record was an increase of 2.93ppm in 1998.
The jump comes as a study published in Science on Thursday looking at global surface temperatures for the past 1,500 years warned that "recent warming is unprecedented", prompting UN climate chief, Christiana Figueres, to say that "staggering global temps show urgent need to act. Rapid climate change must be countered with accelerated action."
Tans told the Associated Press the major factor was an increase in fossil fuel use. "It's just a testament to human influence being dominant", he said. "The prospects of keeping climate change below that [two-degree goal] are fading away."