Skip to comments.Antarctic peninsula was 1.3°C warmer than today 11,000 years ago
Posted on 08/23/2012 5:47:29 PM PDT by Ernest_at_the_Beach
August 23, 2012
From the British Antarctic Survey
New climate history adds to understanding of recent Antarctic Peninsula warming
Results published this week by a team of polar scientists from Britain, Australia and France adds a new dimension to our understanding of Antarctic Peninsula climate change and the likely causes of the break-up of its ice shelves.
The first comprehensive reconstruction of a 15,000 year climate history from an ice core collected from James Ross Island in the Antarctic Peninsula region is reported this week in the journal Nature. The scientists reveal that the rapid warming of this region over the last 100 -years has been unprecedented and came on top of a slower natural climate warming that began around 600 years ago. These centuries of continual warming meant that by the time the unusual recent warming began, the Antarctic Peninsula ice shelves were already poised for the dramatic break-ups observed from the 1990′s onwards.
The Antarctic Peninsula is one of the fastest warming places on Earth average temperatures from meteorological stations near James Ross Island have risen by nearly 2°C in the past 50 years.
Lead author Dr Robert Mulvaney OBE, from British Antarctic Survey (BAS) says,
This is a really interesting result. One of the key questions that scientists are attempting to answer is how much of the Earths recently observed warming is due to natural climate variation and how much can be attributed to human activity since the industrial revolution. The only way we can do this is by looking back through time when the Earth experienced ice ages and warm periods, and ice cores are a very good method for doing this.
Dr Mulvaney continues,
We know that something unusual is happening in the Antarctic Peninsula. To find out more we mounted a scientific expedition to collect an ice core from James Ross Island on the northernmost tip of the Peninsula. Within the 364m long core are layers of snow that fell every year for the last 50,000 years. Sophisticated chemical analysis at BAS and the NERC Isotope Geosciences Laboratory (part of British Geological Survey) was used to re-create a temperature record over this period.
For this study we looked in detail at the last 15,000 years from the time when the Earth emerged from the last ice age and entered into the current warm period. What we see in the ice core temperature record is that the Antarctic Peninsula warmed by about 6°C as it emerged from the last ice age. By 11,000 years ago the temperature had risen to about 1.3°C warmer than todays average and other research indicates that the Antarctic Peninsula ice sheet was shrinking at this time and some of the surrounding ice shelves retreated. The local climate then cooled in two stages, reaching a minimum about 600 years ago. The ice shelves on the northern Antarctic Peninsula expanded during this cooling. Approximately 600 years ago the local temperature started to warm again, followed by a more rapid warming in the last 50-100 years that coincides with present-day disintegration of ice shelves and glacier retreat.
Co-Author Dr Nerilie Abram formerly from British Antarctic Survey and now with the Research School of Earth Sciences, at The Australian National University says,
The centuries of ongoing warming have meant that marginal ice shelves on the northern Peninsula were poised for the succession of collapses that we have witnessed over the last two decades. And if this rapid warming that we are now seeing continues, we can expect that ice shelves further south along the Peninsula that have been stable for thousands of years will also become vulnerable.
Olivier Alemany, from the French Laboratoire de Glaciologie et Géophysique de lEnvironnement was part of the expedition. He says,
The international polar science community has collected and analysed ice cores from Antarctica and Greenland as part of an effort to reconstruct the Earths past climate and atmosphere. Our team wanted to understand how the recent warming and the loss of ice shelves compared to the longer term climate trends in the region.
This research makes a significant contribution to the understanding of the role that Antarcticas ice sheets play in influencing future climate and sea-level rise. It was funded by NERC (Natural Environment Research Council).
Regarding that rapid warming of 2C in the last 50 years, just remember that most weather stations in the Antarctic are near humanity, and humanity requires warmth to survive. For example:
The Antarctic peninsula is the most populated place in Antarctica.
Because their snow mobiles were gas guzzlers AND the dogs farted a lot.
Whoa...that’s it. We’re doomed!!!
How much is that 11,000 year old thermometer selling for? It ought to be a collector’s item.
Slap the editor that wrote the headline up side the head.
What a joke! Just effect me not with any of your policies. I have 200 incandescent light bulbs in storage. I suffer nothing from you idiots.I drill water restrictors out of my three shower heads. I have well water in 72 feet of ocean under my vast property and I pump it endlessly into my fishing lakes and grass.( because I own it!!). I use freon!!!
Hot, cold; who gives a flying crap anymore?
WTF? Why go off at me?
|GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach|
I seriously question how the temperature 11,000 years or more ago can be estimated to within a tenth of a degree.
Dog farts might account for the .3 degree C, but I think Mammoth farts accounted for the 1.0 degree C.
Thanks for the ping.
I would submit that Al Gore would rather have members of the press do the scientific work on these climate phenomena. :)
Thanks for the posts. I have been working a lot. Just enough time to keep up the home front.
Having studied this, more scientists are leaning to a period around 16,000 years ago as the first initial warming and glacier melt from the last ice age.
Ironically, the polar ice cap began on the continents millions of years ago as the Tectonic plates began to move or an area where they were all joined was one of the polar ice caps. India, Brazil and such were all part of this initical glacier action millions of years ago with all the plates were joined at the hip.
So where are we now, for the last 2,000 years the earth has overall cooled a few degrees based on tree-ring research. Right now, other than for the drought, we are in a warm period that is coming to an end and the cooling period will be over around 2035 before we warm up again.
I said that to say this, stock up on canned food and wood.
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