As China flexes its muscles in Antarctica, science is the best diplomatic tool on the frozen continent


Adrian McCallum, University of the Sunshine Coast

Science has always drawn people and nations to Antarctica. But territorial claims and political tensions are also part of the history of that continent.

China is investing heavily in infrastructure and capability in Antarctica with research stations, airfields, field camps and plans for more. Science must continue to play a pivotal role in easing territorial tensions, as interest in Antarctica increases.


Read more: How China came in from the cold to help set up Antarctica’s vast new marine park


A brutal scientific history

Some argue that Captain Robert Scott and his team perished on their infamous return journey from the South Pole because of their dogged determination to haul 15kg of geological specimens.

Science has always nestled alongside the dominant motivation of territorial claims. But in Antarctica, it has evolved as a tool of diplomacy between nations, as a means to suppress tensions about national claims to the land.

This tension is not new. It was during his 1929–31 expedition that Sir Douglas Mawson claimed what is now the Australian Antarctic Territory (AAT) as British sovereign territory, with sovereignty eventually being transferred to Australia in 1936.

Australia’s National Antarctic Research Expeditions (ANARE), formalised in 1947, were not established for scientific reasons. Rather, they were meant to support our territorial claims and enable investigation of valuable mineral and marine resources located within the AAT.

A recent event in Hobart held by the Australian Academy of Science, examining the future of antarctic science was underscored by such themes.

A time of increased tensions

In their 2016 book, The Scramble for the Poles, academics Klaus Dodds and Mark Nuttall suggest that the planting of a Russian flag beneath the North Pole in 2007 precipitated a new scramble for resources in the polar regions.

In their view, there is an ongoing and under-discussed unease among Antarctic players when it comes to territory. This is felt particularly keenly by countries that have publicly reserved their right to make a future Antarctic claim (such as the United States and Russia), and those that have made no such claim, nor reserved such a right (such as China).

Australia is one of the original seven Antarctic claimants; we claim 42% of the continent. Our actions in Antarctica are pivotal as we grapple with increasing interest in the continent from assertive states such as China.

In a Special Report to the Australian Strategic Policy Institute in 2017, Anne-Marie Brady of the University of Canterbury outlined three stations, three airfields and two field camps that China has in the AAT. She also noted China’s intention to build a fourth station on King George Island, with plans for a fifth station for the Ross Sea region.

Only weeks ago, Brady released a book, China as a Polar Great Power that further examines the game changing nature of China’s growing strength at the poles.

This power has grown, she argues, thanks to the country “investing more in capacity than any other nation”. This includes investment in BeiDou, China’s own global GPS network, which will enhance capability for the Chinese military.

What is Australia doing about this?

Australia is emerging from a long period of under-investment in Antarctica to slowly address this geopolitical situation.

In 2012, the US released an examination of its need to renew its infrastructure and logistical capability in Antarctica. In 2016, the Australian Antarctic Division released its own Australian Antarctic Strategy and 20 Year Action Plan.

These documents explain Australia’s future role in Antarctica and outline the measures we need to implement to retain our role as an Antarctic leader. These measures include things such as the re-establishment of our overland traverse capability, an upgrade of our ageing Antarctic stations and the investigation of year-round aviation links.

Progress is being made. Australia’s newest icebreaker was recently named and the first steel was cut in June 2017. A Modernisation Taskforce has been established.

Australia’s new icebreaker will be called RSV Nuyina.
Australian Antarctic Division/Damen/DMS Maritime/Knud E Hansen

Without these vital infrastructure and operational assets, we lose the ability to conduct science across our territorial claim. If we lose this, we can no longer wield science as a valuable diplomatic tool.

Science as a bridge builder

Science has long served as a bridge builder in Antarctica, but how long can it sustain this role?

The importance of ongoing scientific collaboration between Australia and China in Antarctica has been discussed.

It is generally asserted that the capacity of science to serve as a form of “soft power” diplomacy is sound and that sovereignty can best be sustained by deploying a continuous and substantial scientific program.


Read more: Revenge served cold: was Scott of the Antarctic sabotaged by his angry deputy?


But, although Antarctica is considered “a reserve for peace and science” under International governance, the robustness of the Antarctic Treaty too is often discussed. Contemporary media continues to illustrate concerns over our claim in Antarctica.

The Chief of the Australian Defence Force spoke recently on such matters in Washington and a colleague and I are currently examining the implications for Australian Defence policy of other states’ assertive actions in Antarctica.

The ConversationScience must continue to play a pivotal role in sustaining peace in Antarctica so that alternative tools need not be called upon.

Adrian McCallum, Lecturer in Science and Engineering, University of the Sunshine Coast

This article was originally published on The Conversation. Read the original article.

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Why are talks over an East Antarctic marine park still deadlocked?



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An Antarctic icebreaker sails past a penguin. But conservationists are still waiting for their own breakthrough.
John B. Weller, Author provided

Cassandra Brooks, University of Colorado

Last week, representatives from 24 countries plus the European Union met in Hobart to discuss plans for a vast marine protected area (MPA) off the coast of East Antarctica.

The proposed area, spanning almost 1 million square km, is crucial for a vast array of marine life. Scientists, conservationists and governments have been pushing for the protection of this area for upwards of seven years.

Why, then, has the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) failed to deliver, despite having agreed similar protections for other areas of the Southern Ocean?

Competing national incentives among member states, and complex international relations extending far beyond the negotiations themselves, have stymied consensus as states negotiate power and fishing access in this icy commons at the bottom of the world.


Read more: Why Antarctica depends on Australia and China’s alliance


CCAMLR committed to establishing a network of marine parks in the Southern Ocean in 2002 and has enjoyed success. In 2009 it established the world’s first international MPA, covering 94,000 square km south of the South Orkney Islands. Then, in 2016, the Commission made headlines when it successfully negotiated the world’s largest marine park, covering 1.55 million square km in the Ross Sea.

This raised hopes for a similar breakthrough for East Antarctica at this year’s meeting. But those hopes were put on hold for another year.

Vast protections

According to plans first proposed to CCAMLR in 2012 by Australia, France and the EU, the East Antarctic marine park was designed as a representative system of seven marine protected areas, covering 1.8 million square km that would capture key ecosystem processes.

By 2017 the seven zones had been scaled back to three, covering just under 1 million square km – largely to accommodate some member states’ economic interests and political concerns.

CCAMLR current MPAs in the South Orkney Islands (adopted in 2009) and Ross Sea (adopted in 2016) and proposed MPA off the East Antarctic. Original 2012 East Antarctic MPA proposal shown in light purple and current 2017 proposal in dark purple. Figure modified after Brooks et al. 2016.

Coming into 2017, proponents had worked to strengthen the East Antarctic MPA proposal, achieving the support of all states except Russia and China.

This obstruction is not novel. These two states have been the most vocal opponents of MPAs throughout the history of the negotiations, citing a variety of concerns including fishing interests, sufficiency of science, conservation need, and political accusations.

Fishing interests

Fishing interests have been a crucial factor in the negotiations, not just for China and Russia but also for the bulk of fishing states, which make up the majority of the Commission.

One of the reasons the South Orkney Islands reserve was adopted swiftly in 2009 was because it did not interfere with current or future fishing interests. Following this precedent, the Ross Sea marine reserve was designed largely around the lucrative fishing grounds for toothfish, and China only agreed to the plans after a krill-fishing zone was added in 2015 – despite the fact that neither China nor any other member state currently fishes for krill in the Ross Sea.

Small toothfish fisheries are scattered throughout the East Antarctic, including within the proposed MPA. However, this proposal has a multiple-use design, and none of the areas are explicitly closed to fishing. Yet some of Russia’s and China’s opposition concerned potential limitations to fishing. Why?

As a commons where sovereignty is suspended under the Antarctic Treaty, the Southern Ocean continues to be a contested space. Fishing can be used as a means to occupy space in this global commons, meeting geopolitical as well economic goals by asserting power and securing future access.

In recent years China has used the debate over MPAs to challenge the intentions of the very CCAMLR Convention as one inherently offering members a right to fish rather than a responsibility to conserve. A new Chinese krill fishing effort in the East Antarctic that initiated last year may be worth more in terms of geopolitics than it is in terms of money.

Finding opportunities to break the deadlock

How can the deadlock be broken? Perhaps negotiators can learn from the success of the Ross Sea marine park plan where high-level diplomacy created a political window of opportunity. China’s support was secured in 2015, after presidential-level bilateral meetings with the United States.


Read more: How China came in from the cold to help set up Antarctica’s vast new marine park


That left Russia as the only nation not to support the plan – a bad look, given that it was preparing to chair the 2016 meeting, and President Vladimir Putin had declared 2017 a special Year of Ecology. Russia had the opportunity and incentives to demonstrate leadership.

But also importantly, the US Secretary of State John Kerry was personally invested in the outcome, and throughout 2016 he had been liaising with his counterparts in Russia. Pressure was building both inside and outside the meeting room. After securing concessions to increase the amount of toothfish fishing in certain zones, Russia eventually approved the plans.

The process of building consensus for adopting CCAMLR MPAs, with particular focus on the Ross Sea MPA during the 2013–2016 time period. Figure modified after Brooks 2017.

In managing one of the great oceanic commons, despite political plays, CCAMLR has demonstrated leadership in adopting marine protected areas. The Southern Ocean now harbours the world’s largest marine park in the Ross Sea. Despite the latest setback a proposal for the East Antarctic remains on the table as well as plans for other marine parks in the Weddell Sea and off the Antarctic Peninsula.

The ConversationSecuring international agreements takes patience and it is often unclear in the moment how a political window of opportunity opens. It may still take some time to align national incentives and generate international diplomacy for the East Antarctic MPA and the others to come. The Commission’s 25 members ultimately need to find the political will to see it through.

Cassandra Brooks, Assistant Professor Environmental Studies, University of Colorado

This article was originally published on The Conversation. Read the original article.

What if Antarctica’s dormant, ice-covered volcanoes wake up?



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Harvepino / shutterstock

John Smellie, University of Leicester

Antarctica is a vast icy wasteland covered by the world’s largest ice sheet. This ice sheet contains about 90% of fresh water on the planet. It acts as a massive heat sink and its meltwater drives the world’s oceanic circulation. Its existence is therefore a fundamental part of Earth’s climate.

Less well known is that Antarctica is also host to several active volcanoes, part of a huge “volcanic province” which extends for thousands of kilometres along the western edge of the continent. Although the volcanic province has been known and studied for decades, about 100 “new” volcanoes were recently discovered beneath the ice by scientists who used satellite data and ice-penetrating radar to search for hidden peaks.

Some of the volcanoes known about before the latest discovery.
antarcticglaciers.org, Author provided

These sub-ice volcanoes may be dormant. But what would happen if Antarctica’s volcanoes awoke?

We can get some idea by looking to the past. One of Antarctica’s volcanoes, Mount Takahe, is found close to the remote centre of the West Antarctic Ice Sheet. In a new study, scientists implicate Takahe in a series of eruptions rich in ozone-consuming halogens that occurred about 18,000 years ago. These eruptions, they claim, triggered an ancient ozone hole, warmed the southern hemisphere which caused glaciers to melt, and helped bring the last ice age to a close.

Mt Takahe grew over hundreds of thousands of years and its 8km-wide caldera now towers above the ice sheet.
NASA / Jim Yungel, CC BY-SA

This sort of environmental impact is unusual. For it to happen again would require a series of eruptions, similarly enriched in halogens, from one or more volcanoes that are currently exposed above the ice. Such a scenario is unlikely although, as the Takahe study shows, not impossible. More likely is that one or more of the many subglacial volcanoes, some of which are known to be active, will erupt at some unknown time in the future.

Eruptions below the ice

Because of the enormous thickness of overlying ice, it is unlikely that volcanic gases would make it into the atmosphere. So an eruption wouldn’t have an impact like that postulated for Takahe. However, the volcanoes would melt huge caverns in the base of the ice and create enormous quantities of meltwater. Because the West Antarctic Ice Sheet is wet rather than frozen to its bed – imagine an ice cube on a kitchen work top – the meltwater would act as a lubricant and could cause the overlying ice to slip and move more rapidly. These volcanoes can also stabilise the ice, however, as they give it something to grip onto – imagine that same ice cube snagging onto a lump-shaped object.

In any case, the volume of water that would be generated by even a large volcano is a pinprick compared with the volume of overlying ice. So a single eruption won’t have much effect on the ice flow. What would make a big difference, is if several volcanoes erupt close to or beneath any of West Antarctica’s prominent “ice streams”.

A velocity map of Antarctic ice streams as they move toward the ocean.
NASA/JPL, CC BY-SA

Ice streams are rivers of ice that flow much faster than their surroundings. They are the zones along which most of the ice in Antarctica is delivered to the ocean, and therefore fluctuations in their speed can affect the sea level. If the additional “lubricant” provided by multiple volcanic eruptions was channelled beneath ice streams, the subsequent rapid flow may dump unusual amounts of West Antarctica’s thick interior ice into the ocean, causing sea levels to rise.

Under-ice volcanoes are probably what triggered rapid flow of ancient ice streams into the vast Ross Ice Shelf, Antarctica’s largest ice shelf. Something similar might have occurred about 2,000 years ago with a small volcano in the Hudson Mountains that lie underneath the West Antarctica Ice Sheet – if it erupted again today it could cause the nearby Pine Island Glacier to speed up.

The volcano–ice melt feedback loop

Most dramatically of all, a large series of eruptions could destabilise many more subglacial volcanoes. As volcanoes cool and crystallise, their magma chambers become pressurised and all that prevents the volcanic gases from escaping violently in an eruption is the weight of overlying rock or, in this case, several kilometres of ice. As that ice becomes much thinner, the pressure reduction may trigger eruptions. More eruptions and ice melting would mean even more meltwater being channelled under the ice streams.

Mt Erebus is one of Antarctica’s most active volcanoes. The rocks in the foreground are the remnants of several younger subglacial volcanoes.
antarcticglaciers.org, Author provided

Potentially a runaway effect may take place, with the thinning ice triggering more and more eruptions. Something similar occurred in Iceland, which saw an increase in volcanic eruptions when glaciers began to recede at the end of the last ice age.

So it seems the greatest threat from Antarctica’s many volcanoes will be if several erupt within a few decades of each other. If those volcanoes have already grown above the ice and their gases were rich in halogens then enhanced warming and rapid deglaciation may result. But eruptions probably need to take place repeatedly over many tens to hundreds of years to have a climatic impact.

The ConversationMore likely is the generation of large quantities of meltwater during subglacial eruptions that might lubricate West Antarctica’s ice streams. The eruption of even a single volcano situated strategically close to any of Antarctica’s ice streams can cause significant amounts of ice to be swept into the sea. However, the resulting thinning of the inland ice is also likely to trigger further subglacial eruptions generating meltwater over a wider area and potentially causing a runaway effect on ice flow.

John Smellie, Professor of Volcanology, University of Leicester

This article was originally published on The Conversation. Read the original article.

Antarctic Ocean and Climate Change


The link below is to an article that takes a look at the effects of a 1-degree rise in temperature of the Antarctic Ocean.

For more visit:
http://e360.yale.edu/digest/what-happens-to-the-antarctic-ocean-with-1-degrees-celsius-of-warming

How Antarctic ice melt can be a tipping point for the whole planet’s climate


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Melting Antarctic ice can trigger effects on the other side of the globe.
NASA/Jane Peterson

Chris Turney, UNSW; Jonathan Palmer, UNSW; Peter Kershaw, Monash University; Steven Phipps, University of Tasmania, and Zoë Thomas, UNSW

Melting of Antarctica’s ice can trigger rapid warming on the other side of the planet, according to our new research which details how just such an abrupt climate event happened 30,000 years ago, in which the North Atlantic region warmed dramatically.

This idea of “tipping points” in Earth’s system has had something of a bad rap ever since the 2004 blockbuster The Day After Tomorrow purportedly showed how melting polar ice can trigger all manner of global changes.

But while the movie certainly exaggerated the speed and severity of abrupt climate change, we do know that many natural systems are vulnerable to being pushed into different modes of operation. The melting of Greenland’s ice sheet, the retreat of Arctic summer sea ice, and the collapse of the global ocean circulation are all examples of potential vulnerability in a future, warmer world.


Read more: Chasing ice: how ice cores shape our understanding of ancient climate.


Of course it is notoriously hard to predict when and where elements of Earth’s system will abruptly tip into a different state. A key limitation is that historical climate records are often too short to test the skill of our computer models used to predict future environmental change, hampering our ability to plan for potential abrupt changes.

Fortunately, however, nature preserves a wealth of evidence in the landscape that allows us to understand how longer time-scale shifts can happen.

Core values

One of the most important sources of information on past climate tipping points are the kilometre-long cores of ice drilled from the Greenland and Antarctic ice sheets, which preserve exquisitely detailed information stretching back up to 800,000 years.

The Greenland ice cores record massive, millennial-scale swings in temperature that have occurred across the North Atlantic region over the past 90,000 years. The scale of these swings is staggering: in some cases temperatures rose by 16℃ in just a few decades or even years.

Twenty-five of these major so-called Dansgaard–Oeschger (D-O) warming events have been identified. These abrupt swings in temperature happened too quickly to have been caused by Earth’s slowly changing orbit around the Sun. Fascinatingly, when ice cores from Antarctica are compared with those from Greenland, we see a “seesaw” relationship: when it warms in the north, the south cools, and vice versa.

Attempts to explain the cause of this bipolar seesaw have traditionally focused on the North Atlantic region, and include melting ice sheets, changes in ocean circulation or wind patterns.

But as our new research shows, these might not be the only cause of D-O events.

Our new paper, published today in Nature Communications, suggests that another mechanism, with its origins in Antarctica, has also contributed to these rapid seesaws in global temperature.

Tree of knowledge

The 30,000-year-old key to climate secrets.
Chris Turney, Author provided

We know that there have been major collapses of the Antarctic ice sheet in the past, raising the possibility that these may have tipped one or more parts of the Earth system into a different state. To investigate this idea, we analysed an ancient New Zealand kauri tree that was extracted from a peat swamp near Dargaville, Northland, and which lived between 29,000 and 31,000 years ago.

Through accurate dating, we know that this tree lived through a short D-O event, during which (as explained above) temperatures in the Northern Hemisphere would have risen. Importantly, the unique pattern of atmospheric radioactive carbon (or carbon-14) found in the tree rings allowed us to identify similar changes preserved in climate records from ocean and ice cores (the latter using beryllium-10, an isotope formed by similar processes to carbon-14). This tree thus allows us to compare directly what the climate was doing during a D-O event beyond the polar regions, providing a global picture.

The extraordinary thing we discovered is that the warm D-O event coincided with a 400-year period of surface cooling in the south and a major retreat of Antarctic ice.

When we searched through other climate records for more information about what was happening at the time, we found no evidence of a change in ocean circulation. Instead we found a collapse in the rain-bearing Pacific trade winds over tropical northeast Australia that was coincident with the 400-year southern cooling.


Read more: Two centuries of continuous volcanic eruption may have triggered the end of the ice age.


To explore how melting Antarctic ice might cause such dramatic change in the global climate, we used a climate model to simulate the release of large volumes of freshwater into the Southern Ocean. The model simulations all showed the same response, in agreement with our climate reconstructions: regardless of the amount of freshwater released into the Southern Ocean, the surface waters of the tropical Pacific nevertheless warmed, causing changes to wind patterns that in turn triggered the North Atlantic to warm too.

The ConversationFuture work is now focusing on what caused the Antarctic ice sheets to retreat so dramatically. Regardless of how it happened, it looks like melting ice in the south can drive abrupt global change, something of which we should be aware in a future warmer world.

Chris Turney, Professor of Earth Sciences and Climate Change, UNSW; Jonathan Palmer, Research Fellow, School of Biological, Earth and Environmental Sciences., UNSW; Peter Kershaw, Emeritus Professor, Earth, Atmosphere and Environment, Monash University; Steven Phipps, Palaeo Ice Sheet Modeller, University of Tasmania, and Zoë Thomas, Research Associate, UNSW

This article was originally published on The Conversation. Read the original article.

Drones help scientists check the health of Antarctic mosses, revealing climate change clues



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Mosses are sensitive to even minor changes in their living conditions.
Sharon Robinson, Author provided

Zbyněk Malenovský, University of Tasmania and Arko Lucieer, University of Tasmania

Drones are helping scientists check the health of Antarctic mosses, revealing clues on the pace of climate change.

The scientists say their method could be used for similar research in other harsh environments like desert or alpine regions.

Mosses are sensitive to even minor changes in their living conditions, and scientists traditionally tramped through difficult terrain to collect data on them.

Using the specially-designed drones is faster, kinder to the environment and delivers detailed images that satellite imagery cannot match.

Drones also allow to map much larger areas than previously possible, showing how the moss health responds to meltwater in real time.

The ConversationThese methods could be used for similar research in other harsh environments like desert or alpine regions.

Zbyněk Malenovský, Researcher in Remote Sensing of Vegetation, University of Tasmania and Arko Lucieer, Associate Professor in Remote Sensing, University of Tasmania

This article was originally published on The Conversation. Read the original article.

Antarctic ice reveals that fossil fuel extraction leaks more methane than thought



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The analysis of large amounts of ice from Antarctica’s Taylor Valley has helped scientists to tease apart the natural and human-made sources of the potent greenhouse gas methane.
Hinrich Schaefer, CC BY-ND

Hinrich Schaefer, National Institute of Water and Atmospheric

The fossil fuel industry is a larger contributor to atmospheric methane levels than previously thought, according to our research which shows that natural seepage of this potent greenhouse gas from oil and gas reservoirs is more modest than had been assumed.

In our research, published in Nature today, our international team studied Antarctic ice dating back to the last time the planet warmed rapidly, roughly 11,000 years ago.

Katja Riedel and Hinrich Schaefer discuss NIWA’s ice coring work at Taylor Glacier in Antarctica.

We found that natural seepage of methane from oil and gas fields is much lower than anticipated, implying that leakage caused by fossil fuel extraction has a larger role in today’s emissions of this greenhouse gas.

However, we also found that vast stores of methane in permafrost and undersea gas hydrates did not release large amounts of their contents during the rapid warming at the end of the most recent ice age, relieving fears of a catastrophic methane release in response to the current warming.

The ice is processed in a large melter before samples are shipped back to New Zealand.
Hinrich Schaefer, CC BY-ND

A greenhouse gas history

Methane levels started to increase with the industrial revolution and are now 2.5 times higher than they ever were naturally. They have caused one-third of the observed increase in global average temperatures relative to pre-industrial times.

If we are to reduce methane emissions, we need to understand where it comes from. Quantifying different sources is notoriously tricky, but it is especially hard when natural and human-driven emissions happen at the same time, through similar processes.


Read more: Detecting methane leaks with infrared cameras: they’re fast, but are they effective


The most important of these cases is natural methane seepage from oil and gas fields, also known as geologic emissions, which often occurs alongside leakage from production wells and pipelines.

The total is reasonably well known, but where is the split between natural and industrial?

To make matters worse, human-caused climate change could destabilise permafrost or ice-like sediments called gas hydrates (or clathrates), both of which have the potential to release more methane than any human activity and reinforce climate change. This scenario has been hypothesised for past warming events (the “clathrate gun”) and for future runaway climate change (the so-called “Arctic methane bomb”). But how likely are these events?

Antarctic ice traps tiny bubbles of air, which represents a sample of ancient atmospheres.
Hinrich Schaefer, CC BY-ND

The time capsule

To find answers, we needed a time capsule. This is provided by tiny air bubbles enclosed in polar ice, which preserve ancient atmospheres. By using radiocarbon (14C) dating to determine the age of methane from the end of the last ice age, we can work out how much methane comes from contemporary processes, like wetland production, and how much is from previously stored methane. During the time the methane is stored in permafrost, sediments or gas fields, the 14C decays away so that these sources emit methane that is radiocarbon-free.

In the absence of strong environmental change and industrial fossil fuel production, all radiocarbon-free methane in samples from, say, 12,000 years ago will be from geologic emissions. From that baseline, we can then see if additional radiocarbon-free methane is released from permafrost or hydrates during rapid warming, which occurred around 11,500 years ago while methane levels shot up.

Tracking methane in ice

The problem is that there is not much air in an ice sample, very little methane in that air, and a tiny fraction of that methane contains a radiocarbon (14C) atom. There is no hope of doing the measurements on traditional ice cores.

Our team therefore went to Taylor Glacier, in the Dry Valleys of Antarctica. Here, topography, glacier flow and wind force ancient ice layers to the surface. This provides virtually unlimited sample material that spans the end of the last ice age.

A tonne of ice yielded only a drop of methane.
Hinrich Schaefer, CC BY-ND

For a single measurement, we drilled a tonne of ice (equivalent to a cube with one-metre sides) and melted it in the field to liberate the enclosed air. From the gas-tight melter, the air was transferred to vacuum flasks and shipped to New Zealand. In the laboratory, we extracted the pure methane out of these 100-litre air samples, to obtain a volume the size of a water drop.

Only every trillionth of the methane molecules contains a 14C atom. Our collaborators in Australia were able to measure exactly how big that minute fraction is in each sample and if it changed during the studied period.

Low seepage, no gun, no bomb

Because radiocarbon decays at a known rate, the amount of 14C gives a radiocarbon age. In all our samples the radiocarbon date was consistent with the sample age.

Radiocarbon-free methane emissions did not increase the radiocarbon age. They must have been very low in pre-industrial times, even during a rapid warming event. The latter indicates that there was no clathrate gun or Arctic methane bomb going off.

So, while today’s conditions differ from the ice-covered world 12,000 years ago, our findings implicate that permafrost and gas hydrates are not too likely to release large amounts of methane in future warming. That is good news.

Wetlands must have been responsible for the increase in methane at the end of the ice age. They have a lesser capacity for emissions than the immense permafrost and clathrate stores.

Geologic emissions are likely to be lower today than in the ice age, partly because we have since drained shallow gas fields that are most prone to natural seepage. Yet, our highest estimates are only about half of the lower margin estimated for today. The total assessment (natural plus industrial) for fossil-fuel methane emissions has recently been increased.

In addition, we now find that a larger part of that must come from industrial activities, raising the latter to one third of all methane sources globally. For comparison, the last IPCC report put them at 17%.

The ConversationMeasurements in modern air suggest that the rise in methane levels over the last years is dominated by agricultural emissions, which must therefore be mitigated. Our new research shows that the impact of fossil fuel use on the historic methane rise is larger than assumed. In order to mitigate climate change, methane emissions from oil, gas and coal production must be cut sharply.

Hinrich Schaefer, Research Scientist Trace Gases, National Institute of Water and Atmospheric

This article was originally published on The Conversation. Read the original article.