Once again, climate scientists use a single tree to define global change

From Keele University and the “It’s like deja vu all over again”  department with the leader of the “ship of fools” thrown in for comic relief. Long-time WUWT readers surely remember the single “Most influential tree in the world” from the Yamal fiasco, where the “signal” in one tree (YAD06) biased an entire paper making it worthless. Well, here we are again with another single tree used to define the entire globe. Obviously they’ve learned nothing, then again, it’s Chris Turney.

Loneliest tree in the world marks new age for our planet

An international research team, including Professor Christopher Fogwill from Keele University, has pinpointed a new geological age, the Anthropocene.

When humans first set foot on the moon in 1969, the people of that decade thought the world had changed forever. Little did they know the world had already laid down the precise marker of a far greater global change four years earlier, signalling our planet had entered an entirely new geological epoch, a time period defined by evidence in rock layers, the Anthropocene.

That new epoch began between October and December 1965 according to new research published today in Scientific Reports by members of the Australasian Antarctic Expedition 2013-2014, which was co-led by co-author Professor Christopher Fogwill from Keele University.

The researchers were able to mark this profound change so precisely because of a “golden spike” found in the heartwood of a strange and singular tree, a Sitka Spruce found on Campbell Island, a World Heritage site in the middle of the Southern Ocean (pictured top left, credit: Pavla Fenwick). The spruce is locally referred to as ‘the loneliest tree in the world’ with the next closest tree over 200km away on the Auckland Islands.

The isolated Sitka spruce on the South Ocean’s Campbell Island is considered the “loneliest tree in the world.” Photo by Chris S. M. Turney, et al./Scientific Reports

The radioactive carbon spike was created by the culmination of mostly Northern Hemisphere atmospheric thermonuclear bomb tests in the 1950s and 1960s. The signal was fixed in the wood of the Campbell Island Sitka spruce by photosynthesis.

Professor Fogwill, Head of the School of Geography, Geology and the Environment at Keele University, said:

“The impact that humanity’s nuclear weapons testing has had on the Earth’s atmosphere provides a global signal that unambiguously demonstrates that humans have become the major agent of change on the planet. This is an important, yet worrying finding. The global atomic bomb signal, captured in the annual rings of this invasive tree species, represents a line in the sand, after which our collective actions have stamped an indelible mark, which will define this new geological epoch for generations to come.”

Various researchers from around the world have been talking about declaring a new geological epoch called the Anthropocene, indicating the point where human influence on the planet fundamentally changed the natural world. However, for a new epoch to be officially declared there must be a clear and precise “global” signal that can be detected in the geological forming materials of the future. This radiocarbon spike is that signal.

Lead author Professor Chris Turney, from University of New South Wales, said:

“We were incredibly excited to find this signal in the Southern Hemisphere on a remote island, because for the first time it gave us a well defined global signature for a new geological epoch that could be preserved in the geological record. Thousands of years from now this golden spike should still stand as a detectable marker for the transformation of the Earth by humankind.”

In the Northern Hemisphere, the atmospheric radiocarbon peak occurred in 1964 where the signal is preserved in European trees. That same peak took until late 1965 to reach the Southern Hemisphere atmosphere. With that, the signal became global, precise and detectable in the geological record, meaning it fitted the requirements as a marker for a new epoch.

Levels of radiocarbon recorded on Campbell Island peaked in late 1965. Image: Turney et al

The 100-year-old tree itself is an anomaly in the Southern Ocean. It is naturally found along the North American Pacific Coast but it is credited with being planted on Campbell Island by the Governor of New Zealand in 1901. The oceanic climate has had an unusual effect on the spruce. Although it has grown to 10m tall, the tree has never produced cones, suggesting it has remained in a permanently juvenile state.

If traces of nuclear testing were present even on Campbell Island then the bombs must have had a truly global impact. Image: Turney et al.

Co-author Professor Mark Maslin, from University College London, said:

“It seems somehow apt that this extraordinary tree, planted far from its normal habitat by humans has also become a marker for the changes we have made to the planet, it is yet further evidence, if that was needed, that in this new epoch no part of our planet remains untouched by humans.”

The study:

Global Peak in Atmospheric Radiocarbon Provides a Potential Definition for the Onset of the Anthropocene Epoch in 1965

Abstract

Anthropogenic activity is now recognised as having profoundly and permanently altered the Earth system, suggesting we have entered a human-dominated geological epoch, the ‘Anthropocene’. To formally define the onset of the Anthropocene, a synchronous global signature within geological-forming materials is required. Here we report a series of precisely-dated tree-ring records from Campbell Island (Southern Ocean) that capture peak atmospheric radiocarbon (14C) resulting from Northern Hemisphere-dominated thermonuclear bomb tests during the 1950s and 1960s. The only alien tree on the island, a Sitka spruce (Picea sitchensis), allows us to seasonally-resolve Southern Hemisphere atmospheric 14C, demonstrating the ‘bomb peak’ in this remote and pristine location occurred in the last-quarter of 1965 (October-December), coincident with the broader changes associated with the post-World War II ‘Great Acceleration’ in industrial capacity and consumption. Our findings provide a precisely-resolved potential Global Stratotype Section and Point (GSSP) or ‘golden spike’, marking the onset of the Anthropocene Epoch.

Open access here: https://www.nature.com/articles/s41598-018-20970-5

 

 


So who says 1965 is the beginning of a new Epoch? There’s no consensus, and they can’t even decide if that’s the name. From Wikipedia’s definition of the Anthropocene:

As of August 2016, neither the International Commission on Stratigraphy nor the International Union of Geological Sciences has yet officially approved the term as a recognized subdivision of geological time,[3][5][6] although the Working Group on the Anthropocene (WGA) voted to formally designate the epoch Anthropocene and presented the recommendation to the International Geological Congress on 29 August 2016.

In January 2015, 26 of the 38 members of the International Anthropocene Working Group published a paper suggesting the Trinity test on 16 July 1945 as the starting point of the proposed new epoch.[20] However, a significant minority supports one of several alternative dates.[20] A March 2015 report suggested either 1610 or 1964 as the beginning of Anthropocene.[21] Other scholars point to the diachronous character of the physical strata of the Anthropocene, arguing that onset and impact are spread out over time, not reducible to a single instant or date of start.[22]

A January 2016 report on the climatic, biological, and geochemical signatures of human activity in sediments and ice cores suggested the era since the mid-20th century should be recognised as a distinct geological epoch from the Holocene.[23]

Turney is just looking to get his name listed as the identifier of the Anthropocene, nothing more. Fortunately, it won’t be decided by him.

The study is nothing but a headline grabber posing as science, just like Chris Turney’s original “Spirit of Mawson” aka “ship of fools” fiasco.

via Watts Up With That?

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February 19, 2018 at 12:27PM

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