ENVIRONMENT by Peter WestmoreNews Weekly
NASA presents Antarctic ice-melt conjecture as fact
, June 6, 2015
A speculative article published by five researchers in the online journal, Earth and Planetary Science Letters, predicting the breakdown of a minor ice shelf in Antarctica, has been widely reported by NASA and the media as evidence that the Antarctic ice sheet will disappear by 2020.
The authors of the study looked at the Larsen B ice shelf, one of many which circle the Antarctic continent.
It is located high on the Antarctic peninsula, a mass of mountains and ice which stretch upwards from the Antarctic continent towards South America, to a latitude of 67 degrees south. (Cape Horn, the southern-most point in the South American continent, reaches down to 58 degrees south.)
Ice shelves are constantly forming and breaking off, under the influences of glacial flows, warm and cold ocean currents, solar energy and the fierce winds which circle Antarctica.
The Larsen shelves are subject to complex interactions of cold and warmer waters originating in the tropics, which flow down the east side of South America, then flow into the Falklands Current in the South Atlantic Ocean.
To give an idea of its relative size, the Larsen B ice shelf consisted of about 3250 square kilometres of ice, compared with the 48,000-square-kilometre Larsen C ice shelf, which is stable, and the nearby Ronne-Filchner ice shelf, which is 422,000 square kilometres, and the Ross ice shelf, which is 473,000 square kilometres.
The Larsen B ice shelf largely disintegrated in 2002, and the latest article speculated that remainder of Larsen B could disappear by 2020.
The text of the research paper was hedged with qualifications. The researchers’ title was “The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers”.
By the time the paper was reported by NASA, it was headlined, “NASA study shows Antarctica’s Larsen B Ice Shelf nearing its final act”.
The NASA media release declared: “A new NASA study finds the last remaining section of Antarctica’s Larsen B Ice Shelf, which partially collapsed in 2002, is quickly weakening and likely to disintegrate completely before the end of the decade.”
This was then exaggerated further by other media. The U.S. NPR (National Public Radio) network reported, “Massive Antarctic Ice Shelf will be gone within years, NASA says”.
It said: “In 2002, NASA released dramatic images that showed a portion of Antarctica’s Larsen B Ice Shelf collapse and disappear. Now, the space agency says what’s left of the massive feature will be gone before the end of the decade.
“As NPR’s Christopher Joyce reported in March, climate change has been accelerating the pace of disintegration of the 625-square-mile, 1600-foot-thick Larsen B. Now a team led by Ala Khazendar of NASA’s Jet Propulsion Laboratory has found that the ice is melting so fast that the shelf will be gone before 2020” (May 15, 2015).
The headline on the story in the London Telegraph was equally dramatic. It said, “After 10,000 years giant Antarctic Ice Shelf will be gone by 2020, NASA report says.”
It introduced the story with the words: “New NASA studies warn of ‘bad news for our planet’ as looming crack threatens to shatter Larsen B Ice Shelf into pieces” (May 17, 2015).
The left-wing Guardian headlined its story, “Vast Antarctic ice shelf a few years from disintegration, says NASA”.
It reported: “The last intact section of one of Antarctica’s mammoth ice shelves is weakening fast and will likely disintegrate completely in the next few years, contributing further to rising sea levels, according to a NASA study released on Thursday.”
Earlier reports in the Guardian include: “Thinning Antarctic ice shelf could contribute to sea-level rise, says study” (May 13, 2015), and “Melting Antarctic: failure to act now on emissions could raise oceans by metres” (May 5, 2015).
To put these reports into context, on 8 October last year, NASA itself reported, “Antarctic sea ice reaches new record maximum”. Its statement said: “Sea ice surrounding Antarctica reached a new record high extent this year, covering more of the southern oceans than it has since scientists began a long-term satellite record to map sea ice extent in the late 1970s.”
The increase in sea ice around the Antarctic continent is only part of the story. Far more important is whether the amount of snow and ice on the continent is increasing or declining.
The quantity of snow and ice on the continent is very difficult to determine, because Antarctica is almost completely covered in a thick blanket of ice, and there is constant calving (breaking off) of glaciers into the sea.
A recent 2012 study, led by Jay Swally of NASA (a global-warming enthusiast) found that from 2003 to 2008, “the mass gain of the Antarctic ice sheet from snow accumulation exceeded the mass loss from ice discharge by 49 gigatonnes/year.”
Clearly, reports of Antarctic ice melting are wildly exaggerated.