Bronze Age lost its cutting edge before climate crisis

Bronze Age lost its cutting edge before climate crisis

Archaeologists claim to have unearthed evidence in Ireland that it was the rising power of iron, not climate change, that brought about the collapse of many ancient civilizations.

LONDON, 23 November, 2014 − Climate change – so often and so recently coupled with the decline of early civilizations in the Near East, the Indus Valley and the Mediterranean – may not have ushered in the collapse of the late Bronze Age after all.

A new study suggests that Bronze Age cultures everywhere collapsed not because of sustained drought or flooding, but because of technological change. The gradual spread of iron foundries and smithies, they say, undermined the economic strengths of those centres with monopolies on the production of, and trade in, copper and tin − the elements in the alloy bronze.

Ian Armit, an archaeologist at the University of Bradford in the UK, and colleagues base their argument on careful studies of ancient climate, using a combination of pollen data and other evidence, plus 2,000 precision-dated archaeological finds from Ireland, from between 1200 BC and 400 AD. This evidence tells a different, but equally familiar, story.

Went wrong

They report in the Proceedings of the National Academy of Sciences that although there was indeed a climate crisis around 750 BC – an event linked to the end of the cultures associated with Knossos in Crete and Mycenae in the Peloponnese – things had started to go wrong two generations or more before.

There had been a clear peak in human activity between 1050 and 900BC, followed by a steady decline and then a rapid fall between 800 AD and 750BC. Since copper was mined in Ireland – and alloyed with tin from Britain to make bronze – the Celtic populations of the place and time enjoyed high socio-economic status and power.

“The impact of climate change on humans is a huge concern today as we monitor rising temperatures”

They were involved in international trade, and at the heart of a global culture. Bronze, both literally and metaphorically, gave the Irish of the time a cutting edge. Such power and status started to evaporate with the advance of iron smithies. Copper and tin are relatively rare metals, but iron is found almost everywhere.

“Our evidence shows definitively that the population decline in this period cannot have been caused by climate change,” Professor Armit concludes.

But he says that the switch to increasingly rainier conditions in Ireland in 750 BC would have had its own impact. “It is likely that poor climatic conditions would have affected farming. This would have been particularly difficult for vulnerable communities, preventing population recovery for several centuries.”

Archaeology is a combative science: the evidence is preserved only precariously and a new discovery can, and often does, change the picture.

Contributing factor

Written records are fragmentary, interpretations open to dispute, and artefacts are often difficult to date. So reconstructions of the distant past are always tentative, and other groups have been careful to “link” or “associate” climate change with historical conflict. Climate would be a contributing factor, not necessarily a prime cause.

But the British scientists argue that, on the evidence from Ireland, a global bronze age civilization was coming to an end for reasons that were ahead of, and independent of, drought or flood, heat waves or sustained cold.

Professor Armit says: “The impact of climate change on humans is a huge concern today as we monitor rising temperatures globally.

“Often, in examining the past, we are inclined to link evidence of climate change with evidence of population change. Actually, if you have high-quality data and apply modern analytical techniques, you get a much clearer picture and start to see the real complexity of human/environment relationships in the past.” – Climate News Network

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Iron’s mixed blessing for health of oceans

Iron’s mixed blessing for health of oceans

New research shows that iron fertilisation stimulates growth of the plankton that help transport carbon dioxide to the deep ocean – but swells the number of small creatures who feed on plankton and whose shells put CO2 back into the atmosphere.

LONDON, 16 November, 2014 − Technology’s answer to climate change in a world in which humans go on releasing carbon dioxide in the atmosphere has just had another setback. The idea of fertilising the planet’s oceans with iron filings to stimulate green growth and turn the oceans into a carbon sink isn’t so simple as hoped.

Two studies – both involving experiments at sea – have confirmed that trace elements such as iron affect plankton growth, and that more iron can mean more carbon dioxide exported to the sea bed in the form of dead and buried life forms. But new research in Nature Geoscience shows that the story is more complex.

Ian Salter, bioscience researcher at the Alfred Wegener Institute’s Helmholtz Centre for Polar and Marine Research, Germany, and colleagues report that they took a closer look at what happens around the Crozet Islands in the Southern Ocean − basaltic islands that deliver a steady natural supply of iron to the surrounding waters.

Carbon pumped

More iron meant more phytoplankton, which meant that more carbon was pumped into deeper waters. But more phytoplankton also meant more little creatures such as foraminifera, which graze on phytoplankton, and then make shells of calcium carbonate − a process that puts carbon dioxide back into the atmosphere.

Dr Salter and his colleagues estimate that the carbonate manufacture in waters naturally fertilised by iron reduced the overall amount of carbon transferred to the deep ocean by between 6% and 32%, whereas in waters not fertilised by iron, the reduction was 1% to 4%. So added iron might make the phytoplankton grow, but it also soups up the return of carbon dioxide to the atmosphere.

The finding is not conclusive. It doesn’t settle the question of whether the presence of trace iron ultimately assists the removal of more carbon from the atmosphere in the long term.

It also doesn’t answer questions about how things might work in warmer waters, and doesn’t offer a guide to the overall effect of iron deliberately added to waters where the phytoplankton don’t bloom in profusion.

“We are in the middle of an experiment we cannot reverse, but which we still don’t understand . . .”

But it does provide a snapshot of science in action, and is yet another reminder that the climate system – and especially the traffic in carbon between rock, water, air and living tissue – is immensely complex, and still puzzling.

And if that wasn’t already clear, new research in the Proceedings of the National Academy of Sciences confirms that there is a lot more to be learned about the role of oceans in climate science.

Researchers report that ocean temperatures have been far more variable over the last 7,000 years than anyone had realised.

Thomas Laepple, a climate scientist at the Alfred Wegener Institute, and Peter Huybers, Professor of Earth and Planetary Sciences at Harvard University, US, combed the climate archives, examined indirect evidence from sediment cores and corals and other sources, and reconstructed sea surface temperatures in a range of different locations over a period of thousands of years.

Then they picked 20 climate models and conducted more than 100 test runs to see if they could simulate the same pronounced fluctuations in ocean temperatures in the same places over the same timescale

Greater discrepancies

They could − but only for short periods. The longer the time sequence, the greater the discrepancies. Over timescales of a thousand years, the models underestimated the variations by a factor of 50.

“Fundamentally, there are only two explanations,” Dr Laepple says. “Either the climate archives do not provide reliable temperature data, or the climate models underestimate the variability of the climate. Or both may be true to some extent.”

Neither finding suggests that climate scientists don’t know what they are doing. In fact, quite the reverse: researchers are establishing just what they can be sure about, and what remains uncertain.

Nor does either finding suggest that long-term alarm over the consequences of increasing levels of atmospheric carbon dioxide is based on uncertain science.

Dr Laepple says: “We are in the middle of an experiment we cannot reverse, but which we still don’t understand well enough to make clear statements at the regional level on longer timescales. Unfortunately, we will just have to continue with this uncertainty for some time.” – Climate News Network

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Scientist acts out dramatic effect of climate change

Scientist acts out dramatic effect of climate change

A spellbinding solo performance by veteran climate scientist Chris Rapley puts the climate debate centre stage – and earns the admiration of London theatre critics.

LONDON, 11 November, 2014 − Climate science has just made cultural history – yet again. Following on from the sci-fi blockbuster The Day After Tomorrow and the Al Gore documentary movie An Inconvenient Truth, research has got personal and turned into a five-star dramatic soliloquy on the London stage.

Chris Rapley is a professor of climate science at University College London, a former director of the British Antarctic Survey, a former director of the Science Museum in London − and now, unexpectedly, an actor on the stage of the historic Royal Court theatre.

He is the star and only member of the dramatis personae of 2071, a play named after the date at which, he says, his eldest grandchild will be the age he is now. He has collaborated with playwright Duncan Macmillan, and with Katie Mitchell, a director with a track record of interest in the hard themes of humanity’s future on Earth.

No physical action

The performance, however, could almost be called anti-theatre. There is no conflict, no violence, and there is − beyond the discreet waving of a hand or the re-positioning of a leg − almost no physical action at all. The actor Rapley sits in one place, with only a glass of water as a prop, and embarks on a monologue.

Furthermore, it is in one sense an anti-dramatic monologue, sounding in many ways remarkably like a procession of extracts from the abstracts of scientific papers, or the executive summary of any number of publications of the Intergovernmental Panel on Climate Change.

There are few concessions to popular language: the diction and choice of terminology is of the kind you tend to hear at science briefings.

The difference is that it is gently and intelligently glossed − so cryosphere and lithosphere are identified as the worlds of ice and rock within a second of utterance.

The story unfolds calmly enough, with a kind of curriculum vitae of the actor, then a history of climate, then a history of climate research, and then the conclusions. It is the slow build-up to an alarming set of possibilities in a swift-changing world, with a time interval for action that is diminishing rapidly.

It ought not to work. But for this Climate News Network reporter, it does work − yet another spellbinding testament to that wonderful mix of space, lighting, darkness, silence, muted music, measured words and eager audience that we call theatre.

Emotive topic

Some critics and theatergoers will, inevitably, have reservations. Time Out magazine found its lack of theatricality “not a bad thing: sobriety feels important when tackling such an emotive topic”. The London Evening Standard took a cooler approach: “He lets the data speak for itself. But the approach feels too dry.”

But first responses were warm. There was a generous welcome from the Daily Telegraph, and Michael Billington – a distinguished dramatic critic who has declared his enthusiasm for theatre as a political instrument − gave it the highest rating of all in The Guardian: five stars.

His only complaint is that there is no printed text, as there is a lot of information delivered in a performance that lasts hardly more than 70 minutes.

But Billington writes: “If we look to theatre to increase our awareness of the human condition, the production succeeds on all counts.” And he ends unequivocally: “It is better than good. It is necessary.” − Climate News Network

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Why warnings on climate spark aggressive denials

Why warnings on climate spark aggressive denials

A new book argues that death threats and abuse illustrate how climate change messengers are being demonised in a way that is without parallel in the history of science.

LONDON, 8 November, 2014 − If you don’t like the message on climate change, it seems that the answer is to shoot the messenger.

According to a new book by veteran environmentalist George Marshall, thousands of abusive emails − including demands that he commit suicide or be “shot, quartered and fed to the pigs, along with your family” – were received by climate scientist Michael Mann, director of Pennsylvania State University’s Earth System Science Centre, who drew and published the “hockey stick graph”  that charts a steep rise in global average temperatures.

Glenn Beck, a commentator on Fox TV, called on climate scientists to commit suicide. A climate denial blogger called Marc Morano claimed that one group of climate scientists deserved “to be publicly flogged”. And the late Stephen Schneider found his name and that of other Jewish climate scientists on a “death list” maintained by an American neo-Nazi website.

Very strange

As Marshall points out in his absorbing, all-embracing, immensely readable book, Don’t Even Think About It: Why Our Brains are Wired to Ignore Climate Change, something very strange is going on.

Louis Pasteur’s revolutionary microbiology work on disease prevention never resulted in him having to think about how to use a gun. Jonas Salk never needed to fortify his house as result of working on the development of a polio vaccine.

Other scientists are trusted and respected. But the way climate scientists are now treated, Marshall argues, is without parallel in the history of science: “They have been set up to play that role in a climate storyline that, it would seem, cannot refute climate change without demonising the people who warn us about it.”

Forget, if you can, the people who seem to be whipping up these furious responses. Climate change can only be met or mitigated by action − and there are plenty of reasons why a very large number of people nod in agreement about what must be done and then fail to insist that it is done.

Dan Gilbert, a psychologist who won the Royal Society’s science book prize in 2007 with an examination of the puzzles of happiness, says that climate change is something unlikely to strike fear in the human heart anyway. It is impersonal, it is gradual, it is amoral, and it isn’t – or doesn’t seem to be – happening now.

“A distant, abstract, and disputed threat just doesn’t have the necessary characteristics for seriously mobilising public opinion”

Other researchers have pointed out the alarming tendency, shared by all humans, to believe what they want to believe. Furthermore, climate change is not (death threats and public flogging fantasies aside) an immediate or an emotional issue. “A distant, abstract, and disputed threat just doesn’t have the necessary characteristics for seriously mobilising public opinion,” says the Nobel laureate, Daniel Kahneman.

There are other difficulties. When, for instance, will the awful things start to happen? How do you mobilise public opinion on an argument with uncertain timescales, imprecise outcomes and real puzzles about the costs and benefits of any actions? No one, Marshall says, is ever going to march under a banner of that says “100 months before the Odds Shift into a Greater Likelihood of Feedbacks”.

Marshall founded the Climate Outreach and Information Network (COIN), based in Oxford, England. He is a veteran of Greenpeace and the Rainforest Foundation, and there isn’t much doubt about what he thinks and knows to be true.

But the appeal of this book is that he lets others talk. He examines the political doublethink that seems to infect some legislatures in the US. He listens to the sceptics, the worriers, the oil giants, the conspiracy theorists, the celebrity environmental campaigners, and the other ones who invoke imagery of death, fever and smoking ruin.

And he refers to the University of Oxford’s Future of Humanity Institute, which polled academic experts on global risk, and found an estimate of a “19 per cent probability that the human species will go extinct before the end of the century”.

Altruistic behaviour

The title, direction and burden of this book seem to augur almost apocalyptic failure to confront the coming crisis. But, of course, Marshall pulls out an ace near the end.

He concludes that while human brains may be hard-wired to not worry about what may or may not happen in two generations, they also have an immense capacity for pro-social, supportive and altruistic behaviour.

“Climate change is entirely within our capacity for change,” he says, “It is challenging, but far from impossible.”

That is good to know. And the book ends with some serious advice about how to make the case for action – and instead of capital punishment, we get generously shouty advice in capital letters. CLIMATE CHANGE IS HAPPENING HERE AND NOW, he reminds us. And he urges campaigners to DROP THE ECO-STUFF, especially the polar bears.

Marshall suggests that we really do try to contain global average warming to 2°C. He quotes John Schellnhuber, director of the Potsdam Institute for Climate Impact Research, who told the Australians: “The difference between two and four degrees is human civilisation.” And, yes, do think about it. – Climate News Network

  • Don’t Even Think About It: Why Our Brains Are Wired to Ignore Climate Change, by George Marshall (Bloomsbury, price £20).

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Threat to rivers as hydropower gets set for global boom

Threat to rivers as hydropower gets set for global boom

Scientists predict a doubling in production of renewable energy from hydropower over the next 20 years, but building new dams will have a damaging effect on some of the world’s major rivers.

LONDON, 28 October, 2014 − Hydropower, the renewable technology that sets gravity to work and harnesses the energy of rivers, is about to double its output.

The growth will be mostly in the developing world − but the construction of new dams on rivers in South America, South-east Asia and Africa comes at a cost. Around a fifth of the world’s largest remaining free-flowing rivers will be dammed, which presents yet another threat to the wild things that live in or depend on wild water.

Christiane Zarfl − now assistant professor for Environmental System Analysis at the University of Tübingen, Germany − and former colleagues at the Leibniz Institute of Freshwater Ecology and Inland Fisheries in Berlin presented their findings at the International Alliance of Research Universities congress on global challenges, hosted by the University of Copenhagen. The research is also published in the journal Aquatic Sciences.

Renewables, such as solar energy and wind power, now provide about a fifth of the world’s electricity production, and hydroelectric power makes up four-fifths of that. The researchers believe that, within the next two decades, another 3,700 dams may more than double hydropower’s total electricity capacity to 1,700 GW.

Surge of activity

China will remain the global leader, but because of the surge of activity in other countries, its share will fall from 31% to about 25%. The largest number of new dams in South America will be in the Amazon and La Plata basins of Brazil. In Asia, the biggest effort will be in the Ganges-Brahmaputra basin and along the Yangtze.

But while some national economies look for a brighter electric future from hydropower, others have to confront and come to terms with the capriciousness of freshwater delivery.

Professor Jim Hall, Director of the Environmental Change Institute at the University of Oxford, and colleagues argue in Science magazine  that too much water − as well as too little – can seriously damage a nation’s economic health. And climate change means that this unpredictability is likely to present even greater difficulties in the decades ahead.

But challenges exist already. In Ethiopia, a sustained drought has reduced economic growth by 38%. In Thailand, floods in 2011 cost the country $16 billion in insured losses and $43 billion in overall economic losses. In parts of India, half the annual rainfall splashes onto the dusty soils in just 15 days, and 90% of the annual river flows are concentrated into about four months of the year.

Rainfall can vary according to season and from year to year. Climate scientists have also repeatedly warned of a possible increase in extremes of heat and flood. So there are at least three dimensions to the delivery of water on tap.

In the arid regions – and these include most of Australia, the southwestern US, the Middle East and North Africa – conditions are marked by what hydrologists call “strong interannual variability”, which is a delicate way of saying that droughts can last for years and then end suddenly with catastrophic flash floods.

“When these dimensions are combined,” the report’s authors say, “the situation is most challenging – a wicked combination of hydrology that confronts the world’s poorest people.” – Climate News Network

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Climate linked to shrink in size of Alpine chamois

Climate linked to shrink in size of Alpine chamois

Scientists have found strong evidence that declining body size in herds of the chamois mountain goats that are hunted in the Italian Alps is linked to warmer spring and summer temperatures.

LONDON, 26 October, 2014 − The Alpine chamois is getting smaller. Researchers have found that climate change and a gradual rise in average temperatures over the last 35 years mean that young chamois now weigh about 25% less than animals of the same age did in the 1980s.

The latest find, reported in Frontiers in Zoology, is yet more evidence that bodymass and climatic conditions are linked, and that mammals have a tendency to respond to rising temperatures by dwindling in size.

“Body size declines attributed to climate change are widespread in the animal kingdom, with many fish, bird and animal species getting smaller,” said Tom Mason, a biologist at Durham University in the UK. “However, the decreases we observe here are astonishing. The impact on chamois weight could pose real problems for the survival of these populations.”

Vital statistics

Chamois, a mountain goat-antelope species native to Europe, are hunted every autumn in the Italian Alps − under strict regulation, which has allowed populations to increase. So the researchers had access to the vital statistics of more than 10,000 yearling chamois (Rupicapra rupicapra) shot between 1979 and 2010 in three hunting districts in the mountains of Trento province in northern Italy.

The researchers found “clear negative temporal body mass trends in all sexes and sites” in all three populations.

In cold conditions, higher body mass confers advantage. Bigger animals will have a lower ratio of skin to volume, and therefore conserve warmth more easily. Conversely, in the tropics, smaller creatures have a greater ratio of surface through which they can radiate heat, and more easily maintain thermal equilibrium.

Biologists have confirmed this effect in fossil records: skeletal evidence shows that ancestral horses, deer and primates all got smaller as temperatures soared during a dramatic hot spell 55 million years ago. And they have found tentative evidence in a long study of the weights of America’s wild bison across a range of prairie temperatures.

Scientists have also warned that to survive dramatic global warming, humans could shrink to almost Hobbit-like dimensions.

The Alpine studies establish that the lower bodyweights of the chamois native to the region are linked to temperature, rather than to the availability of food.

Levels of nourishment

The same long-term data records reveal that the Alpine meadows that feed these mountain goats are just as productive, and deliver the same levels of nourishment, as they did four decades ago. But Alpine temperatures on average became between 3°C and 4°C warmer over the same period.

“We know that chamois cope with hot periods by resting more and spending less time searching for food, and this may be restricting their size more than the quality of the vegetation they eat,” said Stephen Willis, a co-author. “If climate change results in similar behavioural and body mass changes in domestic livestock, this could have impacts on agricultural productivity in coming decades.”

Wild animals are anyway under pressure from human population growth and loss of habitat, but the latest findings present new puzzles.

Body mass is valuable: it gets a grazing animal through the harshest winters. So chamois numbers are likely to fall, or may have to be kept low.

Dr Mason said: “This study shows the striking, unforeseen impacts that climate change can have on animal populations.” – Climate News Network

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Universities trash football in waste reduction league

Universities trash football in waste reduction league

Shouts of “what a load of rubbish” are heard at hundreds of football matches around England every weekend – but researchers say fans should direct them at overflowing waste bins rather than at players and referees.

LONDON, 25 September, 2014 − Most English football clubs, and the millions of fans who watch them, don’t think beyond what is going to happen on the pitch in the next 90 minutes. Saving the planet is the last thing on their minds, according to research into the Football League.

At the other end of the scale, universities are seriously concerned about their effect on the environment. The world’s top teaching universities are combining to lower their impact, and believe that their students − the leaders of tomorrow − will continue these efforts when they begin their careers.

Football, which has a major influence on the behaviour of millions of young people, is a major industry in the UK.

Eleven tiers make up English football’s pyramid. The Premier League is at the apex, followed by the Championship and Football Leagues One and Two, and then a national league structure – with 59 leagues across the country providing a feeder system through to the Football League.

This means that hundreds of matches take place each week, attracting crowds of spectators in varying numbers. While the numbers decrease in the lower leagues, the huge amount of games played means the aggregate number of spectators is on a par with the Premier League.

Extra revenue

Of course, the big money is made by Premier League clubs, which get millions in revenue from sponsorship and worldwide TV. But one thing all the clubs have in common is that food and drink generates extra revenue and plenty of waste.

Football does sometimes manage to notch up an environmental goal. Like many large businesses, some of the top clubs take seriously the amount of waste that fans produce during matches − mainly because it costs clubs a lot of money to dispose of it.

For example, Arsenal FC now has its own waste recycling centre, and Manchester City and Manchester United have made such improvements in waste generation and disposal that none of their waste now goes to landfill.

In the lower leagues, however, the problem is still largely ignored.

The School of Biological Sciences at the University of Essex, UK, decided to investigate to see how much rubbish was produced by the highest profile and most popular sport in England, and what effect they had on greenhouse gas emissions.

The amount of waste generated by each one of the nine million fans who watched games in the lower leagues in the 2012/13 season was 3.27 kg each. That amounts to 30,146 tonnes of waste over the season, about a quarter of which went to landfill and produced more than two million kg of carbon dioxide to add to climate change.

In their paper, published in Scientific Research, the researchers say that waste per person at an average lower league match was 10 times that produced on big sporting occasions such as FA Cup finals – less than a quarter of a kilo, compared with 3.27 kg.

The amount produced over a season by the eight lower tiers o f the football league is three times the amount produced at the 2012 London Olympic Games. According to the researchers, this shows that the management of the lower league football clubs need to do more to monitor and reduce their waste.

The incentive, apart from saving the planet, is that taking rubbish to landfill is expensive. The tax each club has to pay per tonne of waste produced has increased from £7 in 1996 to £40 a tonne in 2014.

“Although many corporate organisations have moved to a wider social audit . . . football clubs have not yet moved in this direction”

The paper suggests that football also has a moral responsibility because sport has wider effects than other businesses in providing support and inspiration in such areas as education, health and fitness, environment, art, and culture.

The report concludes: “Although many corporate organisations have moved to a wider social audit of their performance that includes triple bottom line reporting of their economic, environmental and social performance, football clubs have not yet moved in this direction.”

In contrast, some of the world’s top teaching universities − meeting at the University of Copenhagen in Denmark this week – have launched a green guide to reduce their impact on the environment.

The International Alliance of Research Universities (IARU) guide focuses on sharing experience about how universities can become more sustainable. This includes reusing materials, eliminating rubbish and recycling as well as extensive programmes of reducing energy use in laboratories, lecture theatres and residential accommodation.

Among the universities taking part are Oxford and Cambridge in England, Yale in the US, Peking in China, Tokyo in Japan, Eth in Switzerland, and the National Universities of Singapore and Australia.

Green guide

Jørgen Honoré, University Director at Copenhagen, said in launching the guide this week: “Universities have the opportunity to create cultures of sustainability for today’s students and tomorrow’s leaders, and to set their expectations for how the world should be. The green guide provides real-world examples to inspire innovation and creative action at universities around the globe.”

The guide includes 23 case histories from these major universities, including installation of solar roofs, and some have already made big strides in reducing greenhouse gas emissions.

“At the University of Copenhagen, we have already achieved ambitious targets,” Honoré said. “We have reduced our energy consumption per person by 20%, and we have cut our CO2 emissions per person by nearly 30% since 2006.

“Many of our buildings have been made more energy efficient − for example by replacing ventilation units, installing LED lighting, insulating pipes, and making laboratory work more energy efficient.”

In the war on waste reduction, it seems that the current score stands at something like Football United 1, University Academicals 5. – Climate News Network

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‘Amazon of UK’ being destroyed for grouse shooting

‘Amazon of UK’ being destroyed for grouse shooting

Managing moorlands so that more birds can be reared for lucrative shooting parties is adding to climate change by destroying layers of peat and releasing large quantities of stored carbon dioxide into the atmosphere.

LONDON, 6 October, 2014 − Burning large tracts of heather on the peat-covered hills of Britain so that more red grouse can be reared for the rich to shoot has always been controversial.

The revenue from overseas visitors flying in from such places as the Middle East and Japan to shoot birds has long been used by the country estate owners to justify the practice.

But the first definitive scientific report into the effects that burning heather has on wildlife and climate change shows the damage to the environment is far worse than previously thought. The water run-off from the damaged peat also adversely affects the aquatic life in the rivers that drain the moorlands of Britain.

The report was released to coincide with start of the moorland burning season in Britain, when gamekeepers set fire to large areas of old heather in order to encourage new growth next year to feed chicks that will be shot in the autumn.

Britain contains 75% of the world’s remaining heather moorland, and its owners say that without the revenue from grouse shooting it would disappear.

Significant findings

The EMBER report (Effects of Moorland Burning on the Ecohydrology of River basins)  is the result of five years work by a team from Leeds University in the north of England, which is a popular area for shooting grouse.

Among the significant findings was that burning heather dried out and warmed the peat it grows in, causing the peat to disintegrate and release large quantities of stored carbon dioxide − so adding to the perils of climate change.

Professor Joseph Holden, from the School of Geography at the University of Leeds and co-author of the study, said: “Altering the hydrology of peatlands so they become drier is known to cause significant losses of carbon from storage in the soil.

“This is of great concern, as peatlands are the largest natural store for carbon on the land surface of the UK and play a crucial role in climate change. They are the ‘Amazon of the UK’.”

The EMBER project − funded by the Natural Environment Research Council, with additional support from the Yorkshire Water treatment and supply utility − assessed the impacts of heather burning on moorland consisting mainly of peat on higher land.

It compared 120 patches of peat in 10 river catchment areas across the English Pennines, with an equal split between burned and unburned areas. The area studied spanned from near Ladybower Reservoir in Derbyshire to Moor House National Reserve, which straddles the border between Cumbria and County Durham.

The red grouse is a major target during the shooting season. Image: Trish Steel via Wikimedia Commons
The red grouse is a major target during the shooting season
Image: Trish Steel via Wikimedia Commons

Among the numerous important findings of the EMBER project, the researchers discovered that the water table depth – the level below which the ground is saturated with water – is significantly deeper in areas where burning has taken place, compared to unburned areas.

A deeper water table means that the peat near the surface will dry out and degrade, releasing stored pollutants, such as heavy metals into rivers, and carbon into the atmosphere.

Other important findings from EMBER include a decrease in the diversity and population sizes of invertebrates, such as insect larvae, in rivers draining from burned areas, and up to a 20˚C increase in soil temperature in the immediate years after burning, compared to unburned sites.

Dr Brown said: “Even small changes in soil temperature can affect the decomposition of organic matter and the uptake of nutrients by plants. But we found increases as high as 20˚C, with maximum temperatures reaching over 50˚C in some cases.

“Such changes in thermal regime have not previously been considered in the debate over moorland management with fire, but could explain a lot of the changes we see in terms of soil chemistry and hydrology following burning.”

Dr Sheila Palmer, also from the School of Geography at the University of Leeds, and a co-author of the report, concludes: “Our hope is that the EMBER project findings will help all parties involved in assessing the range of benefits and impacts of moorland burning to work together in developing policies for the future management of our uplands.”

However, the Moorland Association, which represents the shooting estates, defended the practice of heather burning to promote greater numbers of grouse.

In a statement, the Association said: “Heather is kept young and vigorous by controlled burning. If left unburned, it eventually grows long and lank, reducing its nutritional value.

Burning cycle

“The burning cycle creates a pattern of different-aged heather. The oldest provides cover for the grouse and other birds; the new shoots, succulent food for birds and sheep. A skilfully burnt moor will have a mosaic of heather and other moor plants of differing ages and the rich variety of wildlife they attract.”

The association says that mowing heather is an alternative to burning, but not always possible because of rough terrain. It is also more expensive.

André Farrar, planning and strategy manager at the Royal Society for the Protection of Birds, which has long campaigned for the end of burning heather and the destruction of wildlife to promote grouse shooting said: “Managed burning has a profound impact on the life support systems of the peatlands in our hills.

“This supports the need to phase out and stop burning on deep peat soils in the uplands. It should also trigger a concerted effort to agree how to bring these special places back into better condition, involving Government, its agencies, and landowners.” – Climate News Network

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UN population growth data is bad news for climate

UN population growth data is bad news for climate

Sophisticated new analysis indicates an 80% probability that the planet’s population will continue to rise this century, with serious implications for food security, political stability − and climate change.

LONDON, 19 September, 2014 − The demographers may have got it wrong. New projections say the population of the planet will not stabilise at 9 billion sometime this century. In fact, there is an 80% likelihood that, by 2100, it will reach at least 9.6 bn − and maybe rise as high as 12.3 bn.

The latest data, published in the US journal Science, has profound and alarming implications for political stability, food security and, of course, climate change, since greater numbers of people mean greater demands on agricultural land, water and fuel.

At the heart of the findings − led by Patrick Gerland, of the United Nations Population Division in New York, and backed by sociologists, statisticians and population scientists from Seattle, Singapore and Santiago in Chile − is both new data and a more sophisticated approach to the mathematical probabilities for fertility and life expectancy, and for international migration.

Larger families

The new evidence is that, contrary to previous expectations, women in Africa are still having larger families − in part, because contraceptives are not available and because mortality linked to HIV infection has been reduced.

So, by the end of the century, Africa – once relatively sparsely populated, but now home to around one billion people – will have to feed between 3.5 bn and 5.1 bn.

The new information is available because the UN Population Division re-examines its calculations every two years − and the new techniques include the adoption of a methodology known to mathematicians as “Bayesian probabilistic”.

In the new scenarios, Africa remains at the heart of the population explosion, and African women on average have 4.6 children. There are 4.4 bn people in Asia now, but this is expected to peak at 5bn in 2050 and then decline. North America, Europe, Latin America are expected to stay below 1bn each.

“Earlier projections were strictly based on scenarios, so there was no uncertainty,” said Dr Gerland. “This work offers a more statistically-driven assessment that allows us to quantify the predictions and offer a confidence interval that could be useful in planning.”

The study makes no mention of climate change, and the demographers are more concerned with the numbers of young workers who will have to support increasingly elderly populations. But population, economic growth and global warming are inexorably linked.

Most climate change predictions, when they incorporate population growth at all, have been based on the long-standing assumption that the planet’s burden of humans will peak around 2050, and then begin a slow decline.

Because of this, some researchers have been able to put forward arguments for optimism and propose that climate change can be contained and food security assured with careful management and new thinking.

But recent research suggests that while climate change will open more land in higher latitudes for potential crop growth, the gains will not be great, because the conditions for multiple harvests in the tropics will be reduced.

There are other factors. For example, land once available for crops is disappearing under tarmac and cement as the world’s cities grow, and even with a projected population peak of 9bn, an estimated additional 1.5 million square kilometers of tilth and pasture would be lost to the cities by 2030.

Losses of farmland

In addition, the encroachment of the world’s deserts and the erosion of once fertile farmland continues to exact its toll. Statisticians say that between 19 hectares and 23 hectares of land is abandoned every minute. With the latest, and more alarming, population projections, these losses of farmland can only increase.

But these are all projections, rather than predictions. Armed with such information, governments could take steps to ensure a more secure future.

The authors of the Science paper argue that fertility decline could be helped by better access to contraception, and by the education of women.

They add, grimly, that things could also get worse: “It should also be noted that the projections do not take into account potential negative feedback from the environmental consequences of rapid population growth.

“The addition of several billion people in Africa could lead to severe resource shortages, which in turn could affect population size through unexpected mortality, migration, or fertility effects.” – Climate News Network

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Bluefin tuna follow prey to warming high Arctic

Bluefin tuna follow prey to warming high Arctic

A research ship’s surprise catch of bluefin tuna further north than ever recorded indicates that climate change is restructuring the food web as the waters of east Greenland get warmer.

LONDON, 8 September, 2014 − Biologists and fishermen aboard a scientific cruise in the Arctic while they investigated mackerel stocks caught more than they bargained for − three large bluefin tuna, each weighing about 100 kilograms.

The research ship was sailing through the Denmark Strait, which separates Greenland from Iceland. Bluefin tuna are very seldom found near Greenland, and there are no other scientific reports of them venturing that far north. The most recent report of a tuna anywhere near was a stranding in 1900, a long way south at Qaqortoq, on the south-western tip of Greenland.

Details of the find, during a cruise in August 2012 organised by the Center for Macroecology, Evolution and Climate at the University of Copenhagen, have now been published in the journal Global Change Biology.

Expanded range

The lead author, Professor Brian MacKenzie, said bluefin tuna usually search for prey in areas where surface temperatures are warmer than 11°C.

At the time of the catch, the Denmark Strait was unusually warm, and one of tuna’s preferred prey species, mackerel, had already expanded their range into the region.

Professor MacKenzie and his colleagues write: “Regional temperatures in August 2012 were historically high and contributed to a warming trend since 1985, when temperatures began to rise.

“The presence of bluefin tuna in this region is likely due to a combination of warm temperatures . . . and immigration of an important prey species to the region. We conclude that a cascade of climate change impacts is restructuring the food web in east Greenland waters.”

They say their data was too limited to estimate how many tuna came so far north, but because bluefins are a schooling species − with schools having from 10 to 100 individuals − and because the three tuna were caught in the same haul, it is likely there were many more present.

The report says: “Satellite imagery showing the spread of warm water from the south-east towards east Greenland suggests that recent warming and climate change may have opened a migration pathway from the European shelf towards Greenland for migratory species.”

It acknowledges that the fish may have swum to the Denmark Strait from the north-west Atlantic, and concludes: “Our results show that rising temperatures have been progressively leading a . . . trophic [high in the food chain] cascade into east Greenland waters via improved thermal conditions for migratory prey and predator species.”

New fishing quotas

Nobody knows why bluefin tuna disappeared from the waters near Denmark and in the Norwegian Sea during the 1960s, nor when they might return. But Iceland and Norway have been allocated new fishing quotas of 30 tonnes each for the species in 2014.

An adult bluefin tuna is typically 1.5m-2m long, but some have been as big as 4.5m and weighed 650 kg. The fish are highly prized for sushi, especially in Japan.

Further climate-related changes in distributions of commercial fish such as mackerel and herring will mean new fishery and ecosystem management plans are going to be needed, says the report’s co-author, Helle Siegstad, head of the Department for Fish and Shellfish at the Greenland Institute of Natural Resources.

The Denmark Strait tuna will be discussed at the annual science conference of the International Council for the Exploration of the Sea (ICES), which starts on 15 September in the Spanish coastal city of A Coruña. – Climate News Network

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