Cutting warming to 1.5°C could put food supply at risk

Cutting warming to 1.5°C could put food supply at risk

Scientists say meeting the tougher demands of many countries on limiting global temperature rise may be technically feasible, but would risk worsening world hunger.

LONDON, 21 May, 2015 – As world leaders try to agree how to prevent global warming from heating the planet by more than 2°C above pre-industrial levels, scientists have tackled an altogether thornier question: can we keep the rise below 1.5°C?

The lower target − demanded by more than 100 countries as a safer goal − is attainable, they say. But there will be little room for error, and getting there will mean not only cutting greenhouse gas emissions, but actually removing carbon dioxide from the atmosphere.

That is not possible with the technology now available. And even if it could one day be done, it would probably have forbiddingly harmful consequences for world food supplies.

However, limiting temperature rise by 2100 to less than 1.5°C is still feasible, say the researchers from the International Institute for Applied Systems Analysis (IIASA) in Austria, the Potsdam Institute for Climate Impact Research (PIK), Germany, and colleagues. They report their findings in the journal Nature Climate Change.

Similar actions

Not surprisingly, the answer includes doing more, and doing it faster. “Actions for returning global warming to below 1.5°C by 2100 are in many ways similar to those for limiting warming to below 2°C,” says IIASA climate researcher Joeri Rogelj, one of the lead authors of the report.

The authors accept that the economic, political, and technological conditions for achieving even 2°C are “substantial”. The negotiations to be held in Paris in December by member states of the UN Framework Convention on Climate Change (UNFCCC) may show what chance there is of meeting them.

The new study identifies key ways of reaching the 1.5°C target by 2100. One is a tight limit on future carbon emissions.

Gunnar Luderer, PIK senior researcher in sustainable solutions, who co-led the study, says: “In 1.5°C scenarios, the remaining carbon budget for the 21st century is reduced to almost half, compared to 2°C scenarios.

“As a consequence, deeper emissions cuts are required from all sectors, and global carbon neutrality would need to be reached 10-20 years earlier than projected for 2°C scenarios.”

Energy efficiency will also need to improve faster, he says.

“The scenarios we assess keep warming
to the lowest levels currently considered
technologically feasible”

But the study finds that staying below 1.5°C would require a radical step change: some time this century, carbon emissions would have to become negative at a global scale.

That is the scientists’ way of saying that significant amounts of CO2 will have to be actively removed from the atmosphere. And there is at present no known way of doing that.

In theory, it is possible − for example, through bio-energy use, combined with carbon capture and storage. But that is a technology that so far remains untested on a large scale.

It would also increase hunger, as the crops needed to produce enough biofuel would compete for land with food plants.

Another idea is to grow more forests, which would sequester carbon in their trees, but this would be open to the same objection − that it would reduce cropland. The higher temperatures in prospect will themselves affect forest growth and health.

Lowest levels

Rogelj told the Climate News Network: “Increased temperatures can make afforestation efforts harder. However, the scenarios we assess here keep warming to the lowest levels currently considered technologically feasible, and this issue will thus have a relatively smaller impact.”

Whatever happens, the authors expect things to get hotter before they have any chance of cooling down.

Rogelj says: “Basically, all our 1.5°C scenarios first exceed the 1.5°C temperature threshold somewhere in mid-century, before declining to 2100 and beyond as more and more carbon dioxide is actively removed from the atmosphere by specialised technologies.”

Over 100 countries worldwide more than half the members of the UNFCCC, including the Alliance of Small Island States (AOSIS) and the Least Developed Countries (LDCs) have declared their support for a 1.5°C target. – Climate News Network

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First head of state backs campaign to save the planet

First head of state backs campaign to save the planet

Hungary’s president boosts an ambitious plan to collect a billion-signature petition aimed at pressuring politicians to agree on radical measures to tackle global warming.

BUDAPEST, 20 May, 2015 – János Áder, the President of Hungary, has become the first head of state to join the Live Earth: Road to Paris campaign that aims to ensure world leaders agree to a binding deal on tackling climate change.

The specific aim is to get a billion signatures from concerned citizens before the UN climate change conference in Paris in December, but organisers are also keen to get as many politicians and celebrities as possible to back the campaign.

The Road to Paris campaign was launched in January at the World Economic Forum in Davos, Switzerland, by former US vice-president Al Gore, songwriter and recording artist Pharrell Williams, and the Emmy award-winning producer and new media entrepreneur, Kevin Wall.

Global voices

Williams, winner of 11 Grammy awards, is Live Earth’s creative director, and music concerts will be staged in Paris, New York, Johannesburg, Sydney, São Paulo and Beijing on June 18, seeking to reach two billion people in 190 countries and unite global voices in demanding environmental accountability from world leaders.

Áder, a former member of the European Parliament’s Committee on the Environment, Public Health and Food Safety, endorsed the campaign at a press briefing in Budapest earlier this month.

Praising Gore’s initiative, Áder talked about the evidence of climate change, available solutions, the positive impacts of green technologies, and the challenges and opportunities of the Paris conference in December.

A spokesperson for Gore told the Climate News Network that the agreement in Paris should involve meaningful emissions reductions commitments at the national level, subject to a system of periodic review, and a long-term goal of net zero-carbon emissions.

Planet-wide shift

A Hungarian website that mirrors the US initiative will seek to encourage widespread local demand for a strong agreement that will dramatically cut emissions and accelerate the planet-wide shift to clean energy, said Zsolt Bauer, of the Hungary-based Regional Environmental Centre (REC).

The REC was instrumental in setting the scene for Áder’s announcement, in partnership with the Climate Reality Project, chaired by  Gore.

Áder has committed to speaking and broadcasting in Hungary to promote the petition, and to raising awareness of the available climate solutions, backed by  the REC nationally and regionally. − Climate News Network

  • Pavel Antonov, a Budapest-based journalist and social researcher, edits Evromegdan.bg, a not-for-profit online magazine for journalism in the public interest, published by BlueLink.net

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Earth wins time as land and seas absorb more carbon

Earth wins time as land and seas absorb more carbon

Climate change has intensified more slowly than scientists had expected because the continents and oceans are absorbing more atmospheric carbon dioxide.

LONDON, 17 May, 2015 − Half of all the carbon emissions from burning fossil fuels remain in the atmosphere. The good news is that only half remain in the atmosphere, while the rest have been taken up by the living world and then absorbed into the land, and the ocean. That is, as carbon dioxide levels in the atmosphere have risen, so also has the planet’s capacity to soak up atmospheric carbon.

The implication is that what engineers call “positive feedback” – in which global warming triggers the release of yet more greenhouse gases into the atmosphere to accelerate yet further warming – doesn’t seem to be at work yet.

The implication, too, is that the world’s governments still have time to launch determined programmes to sharply reduce fossil fuel use, and switch to wind, solar and other renewable energy sources before climate change disrupts the planet’s food security and exacts what could be a devastating toll on the biosphere.

But most climate scientists know all this anyway: the real significance of a new study in the journal Biogeosciences is that US and British scientists have narrowed some of the uncertainties in what climate scientists like to call the carbon budget: how much gets into the atmosphere, where it goes, and how long it stays.

That is because although the big picture – that carbon dioxide levels in the atmosphere are beginning to rise steeply – has been confirmed repeatedly by systematic measurements since 1956, the potential margin of error has been considerable.

“This increased uptake by land and ocean is not only surprising; it’s good news”

“There is no question that land and oceans have, for at least the last five and half decades, been taking up about half of the carbon emitted each year. The outstanding question is, Why?” said Richard Houghton of the Woods Hole Research Center in Massachusetts, one of the authors.

“Most of the processes responsible for that uptake would be expected to slow down as the Earth warms, but we haven’t seen it yet. Since the emissions today are three times higher than they were in the 1960s, this increased uptake by land and ocean is not only surprising; it’s good news.

“Without it, the concentration of CO2 in the atmosphere would be twice what it is, and climate change would be much farther along. But there’s no guarantee that it will continue.”

The carbon budget is an integral part of the climate puzzle: all simulations of how climate will change with increasing emissions from fossil fuels depend on an understanding of how much carbon dioxide concentrates in the atmosphere and what happens to it after that.

In the last few months researchers have reported a dramatic uptake of atmospheric carbon by new forests and the growth of woodland on the world’s savannahs and pinpointed the fjords – those steep, still stretches of sea in mountainous coastlines in the high latitudes – as prime “sinks” for atmospheric carbon.

Uncertainties narrowed

At the same time others have once again confirmed fears that thawing permafrost could release vast quantities of carbon stored for millennia is semi-decayed and now frozen vegetation.

But these have been studies of small pieces of the big puzzle. What the Biogeosciences authors did was to refine two global uncertainties. One is how much fossil fuel is burned each year and the other is how much is stacking up in the atmosphere.

Both sound simple, but the first question is complicated by differences in the ways nations maintain their own energy inventories, and the way they report the details, and the second depends on how the use of land has changed, how the oceans are responding to higher levels of acidification and how carbon dioxide levels vary according to region, and to season.

With greater certainty in the answers to the second question – which began with one single set of measurements at the top of a mountain in Hawaii now replicated worldwide – researchers found they could make more sense of the first question, and narrow the uncertainties to a point where they could write that they were “93% confident that terrestrial C uptake has increased and 97% confident that ocean C uptake has increased in the last five decades.

“Thus it is clear that arguably one of the most vital ecosystem services currently provided by the biosphere is the continued removal of approximately half of atmospheric CO2 emissions from the atmosphere.” − Climate News Network

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Deniers’ voices try to drown out climate scientists

Deniers’ voices try to drown out climate scientists

New study indicates that loud dissent from contrarians may prompt some researchers to soften their language about the threats of climate change.

LONDON, 16 May, 2015 − Climate change denial by contrarians claiming that global warming has stopped, is a natural cycle rather than a consequence of human action, or is simply a hoax or conspiracy can take its toll of climate scientists too.

A new study in Global Environmental Change suggests that the loudest voices of dissent can affect the way researchers who have separately and repeatedly confirmed the reality of global climate change then talk about their own research.

Scoffing by contrarian voices can lead researchers to over-emphasise the inevitable scientific uncertainties, or over-react to claims of alarmism, or even adopt some of the contrarian language – chief of which has been talk of a “pause” or “hiatus” in global warming in the 21st century.

Psychological mechanisms

Stephan Lewandowsky, professor at the University of Bristol School of Experimental Psychology in the UK, and colleagues from the US and Australia call the problem “seepage”. That is, the language of the contrarians has seeped into scientific discourse.

The researchers identify three psychological mechanisms, which they call “stereotype threat”, “pluralistic ignorance” and “third-person effect”.

The first acts as a behaviour response: stereotype climate scientists as alarmist and this triggers a natural reaction to avoid the stereotype and downplay the climate threat, or at least not highlight the risks.

“The public has a right to be informed of risks,
even if they are alarming”

Pluralistic ignorance follows when a noisy minority opinion gets disproportionate play in public debate − that is, when people who thought they were in a majority begin to feel inhibited.

The third-person effect is the assumption that persuasive communications might persuade other people, but not the experts. In fact, there is evidence that even experts can be subtly affected by such talk.

Professor Lewandowsky says: “It seems reasonable to conclude that the pressure of climate contrarians has contributed, at least to some degree, to scientists examining their own theory, data and models, even though all of them permit – indeed expect – changes in the rate of warming over any arbitrarily chosen period.

“We scientists have a unique and crucial role in public policy to communicate clearly and accurately the entire range of risks that we know about. The public has a right to be informed of risks, even if they are alarming.

“Climate scientists have done a great job in pursuing their science under great political pressure, and they have tirelessly rebutted pseudoscientific arguments against their work.

“However, sometimes scientists have inadvertently allowed contrarian claims to frame the language of their scientific thinking, leading us to overstate scientific uncertainty and under-communicate knowledge.”

A second study by US scientists recently confirmed that, in fact, scientists have communicated the knowledge. They have certainly done so to a US legislature rich in Republican representatives who make a point of challenging or dismissing the climate science consensus.

Contrarian voices occasionally claim that the scientific community is “divided” − but such division was not on show in evidence presented to the US Congress.

Expert witnesses

Xinsheng Liu, associate research scientist at Texas A&M University, and colleagues report in the journal Climatic Change that they analysed 1,350 testimonies delivered to 253 congressional hearings from 1969 to 2007.

Of the expert witnesses who expressed a view, 86% said that climate change was happening, and 78% said it was a consequence of human activity. Most significantly, 95% of those scientists who gave testimony supported action to combat climate change.

So a “supermajority” of scientific opinion had presented the facts to Congress, and the near-complete agreement in the science community had been consistently presented.

“Possible explanations for policymakers’ contention must be based on something other than a lack of knowledge or divided scientific information,” the report’s authors conclude. – Climate News Network

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Weather events taken to extremes by climate change

Weather events taken to extremes by climate change

Scientists warn that global warming could greatly increase the likelihood of droughts, floods and heatwaves reaching record levels of frequency and intensity.

LONDON, 15 May, 2015 − As temperatures soar to record heights, blame it on global warming − but only about three-quarters of the time. And when the rain comes down by the bucketful, you can attribute one downpour in five to climate change.

Yet another team of research scientists has looked at the probabilities, and has linked extremes of weather with global warming.

Extremes have always happened and are, by definition, rare events. So, for the last 30 years, climate scientists have carefully explained that no particular climate event could be identified as the consequence of a rise in global average temperatures driven by the release of carbon dioxide and other greenhouse gases from the burning of fossil fuels.

But some events that were once improbable have now become statistically more probable because of global warming, according to Erich Fischer and Reno Knutti, climate scientists at ETH Zurich − the Swiss Federal Institute of Technology.

They report in Nature Climate Change that they looked at simulations of probabilities and climate records for the period 1901 to 2005, and projections for the period 2006 to 2100.

Rise in temperatures

Then they settled down to calculate the likelihood that a proportion of past heatwaves or floods could be linked to a measured average rise in planetary temperatures so far of 0.85°C.

They worked out how these proportions would change if the average planetary temperatures reach 2°C above the “normal” of the pre-industrial world, and they found that human-induced global warming could already be responsible for 18% of extremes of rain or snow, and 75% of heatwaves worldwide.

If the temperatures go up to the 2°C that nations have agreed should be the limit, then the probability of precipitation extremes that could be blamed on global warming rises to 40%. They are less precise about heatwaves, but any rise could be sharp.

“If temperatures rise globally by 2°C, we would expect twice as many extreme heat events worldwide than we would with a 1.5% increase,” Dr Fischer says.

“These global warming targets, which are discussed in climate negotiations and which differ little at first glance, therefore have a great influence on the frequency of extremes.”

The researchers are talking about probabilities: it will still be difficult ever to say that one event was a random happening, and another a result of climate change. In such research, there are definition problems. What counts as extreme heat in northern England would not be extreme in India or Saudi Arabia.

But such distinctions could become increasingly academic for people who live in the path of unusual heat and extended drought, or flash floods and catastrophic hailstorms.

A scientist recently told the European Geosciences Union that some regions of the planet will see unprecedented drought, driven once again by climate change, before 2050.

Ignored warnings

Yusuke Satoh, of the International Institute for Applied Systems Analysis, warned that under the notorious business-as-usual scenario −where nations ignore such warnings and just go on burning fossil fuels − 13 of 26 global regions would see “unprecedented hydrological drought levels” by 2050. Some would see this parching much earlier − the Mediterranean by 2027, and the western US as early as 2017.

Such studies are calculated to help provoke governments, states and water authorities into preparing for climate change, but it just may be that the western US is already feeling the heat. California, in particular, has been in the grip of unprecedented drought, and researchers have already linked this to climate change.

Reservoirs and irrigation systems are built on historical data. “But in the next few decades, these historical data may no longer give us accurate information about current conditions,” Dr Satoh says. “The earlier we take this seriously, the better we will be able to adapt.” – Climate News Network

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Permafrost thaw’s runaway effect on carbon release

Permafrost thaw’s runaway effect on carbon release

Arctic warming is causing organic carbon deep-frozen in the soil for millennia to be released rapidly into the air as CO2, with potentially catastrophic impacts on climate.

LONDON, 14 May, 2015 − An international team of scientists has settled one puzzle of the Arctic permafrost and confirmed one long-standing fear: the vast amounts of carbon now preserved in the frozen soils could one day all get back into the atmosphere.

Since the Arctic is the fastest-warming place on the planet, such a release of greenhouse gas could only accelerate global warming and precipitate catastrophic climate change.

That the circumpolar regions of the northern hemisphere hold vast amounts of deep-frozen carbon is not in question.

The latest estimate is 1,700 billion tonnes, which is twice the level of carbon dioxide in the atmosphere and perhaps 10 times the quantity put into the atmosphere by burning fossil fuels since the start of the Industrial Revolution.

Hazard underlined

In recent weeks, researchers have already underlined the potential hazard. But the big question has been that if some of the trapped carbon must be escaping now, where is it going?

Researchers have checked the mouths of the Arctic rivers for the telltale evidence of ancient dissolved organic carbon – partly-rotted vegetable matter deep-frozen more than 20,000 years ago − and found surprisingly little.

Now Robert Spencer, an oceanographer at Florida State University, and colleagues from the US, UK, Russia, Switzerland and Germany report in Geophysical Research Letters that the answer lies in the soil − and in the headwater streams of the terrestrial Arctic regions.

Instead of flowing down towards the sea, the thawing peat and ancient leaf litter of the warming permafrost is being metabolised by microbes and released swiftly into the atmosphere as carbon dioxide.

“We found that decomposition converted 60% of the carbon in the thawed permafrost to carbon dioxide in two weeks”

The scientists conclude that the microbes, once they get a chance to work at all, act so fast that half of all the soil carbon they can get at is turned into carbon dioxide within a week. It gets into the atmosphere before it has much chance to flow downstream with the soil meltwater.

The researchers centred their study on Duvanny Yar in Siberia, where the Kolyma River sluices through a bank of permafrost to expose the frozen organic carbon.

They worked at 19 different sites − including places where the permafrost was more than 30 metres deep − and they found tributary streams made entirely of thawed permafrost.

Measurement of the carbon concentration confirmed that it was indeed ancient. The researchers analysed its form in the meltwater, then they bottled it with a selection of local microbes, and waited.

Used by microbes

“We found that decomposition converted 60% of the carbon in the thawed permafrost to carbon dioxide in two weeks,” says Aron Stubbins, assistant professor at the University of Georgia’s Skidaway Institute of Oceanography. “This shows that permafrost carbon is definitely in a form that can be used by the microbes.”

The finding raises a new – and not yet considered – aspect of the carbon cycle jigsaw puzzle, because what happens to atmospheric and soil carbon is a huge element in all climate simulations.

At he moment, permafrost carbon is not a big factor in projections by the Intergovernmental Panel on Climate Change.

Dr Spencer says: “When you have a huge frozen store of carbon and it’s thawing, we have some big questions. The primary question is, when it thaws, what happens to it?

“Our research shows that this ancient carbon is rapidly utilised by microbes and transferred to the atmosphere, leading to further warming in the region, and therefore more thawing. So we get into a runaway effect.” – Climate News Network

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Green city offers clean alternative to tar sands boom

Green city offers clean alternative to tar sands boom

Canada has been dubbed an international disgrace for its climate change policies, but now one of its major cities is aiming to be the greenest in the world by 2020.

LONDON, 13 May, 2015 − In a country reckoned to have the worst climate policies in the industrialised world, one big city is setting out to defy central government and become 100% carbon neutral.

Vancouver, in British Columbia, Canada, wants to establish itself as “the greenest city in the world by 2020” by demonstrating that economic growth and the welfare of its citizens depends on developing renewables, rapid transit systems, and promoting cycling and walking to curb car use.

It is one of dozens of cities worldwide working towards improving the life of their citizens while reducing fossil fuel use, but it claims to have the most ambitious targets.

Many city administrations in Europe have the support of their governments, but in other countries − particularly Australia and Canada, where governments are actively promoting fossil fuels − cities are having to act alone.

A conference in Vancouver, attended by leaders from 45 countries, opens today to help the local government reach its goals.

Doubling green jobs

Among the “Green Vancouver” targets are doubling the number of green jobs in the city by 2020, from a 2010 baseline of 16,700, and making all new building in the city carbon neutral from 2020, while dramatically cutting emissions from existing buildings.

Progress towards meeting the city’s impressive list of targets includes reductions in air pollution, waste, water use and car journeys. Other aims are to provide a green space within five minutes walk for every citizen, planting thousands of trees, and growing food locally.

The city’s environment credentials go back to the 1970s, when there was a long battle to stop a freeway being built through the city. As a result, it is not possible to drive easily into the centre.

“The people who run Vancouver . . . are
business-savvy people who can see a vibrant green economy being a magnet for new business and forward-looking people”

Between 1996 and 2011, while the population in the city centre increased by 40%, there was a 25% decrease in the number of vehicle journeys, and a rise in the use of public transport, dedicated cycle routes and walkways.

Many other cities in the world that believe the way forward is to rid themselves of fossil fuels are attending to share experience – both of successes and failures.

That Vancouver is to become a centre of excellence is ironic, considering the fact that the federal government is seen as an international disgrace to the environment movement.

In 2011, it repudiated the Kyoto Protocol on emissions reduction targets, and has vigorously promoted the exploitation of oil from tar sands − the most polluting form of oil extraction, with high carbon dioxide emissions.

Power from renewables

In contrast, Vancouver, which has a population of 600,000, believes that all its power can come from renewables – although getting all heating and cooling and transport without using fossil fuels may take until 2040, depending on whether there is any help from central government.

One of the organisers of the conference, Shauna Sylvester, said: “When I first heard that Vancouver wanted to go 100% renewable, I thought it was a dream, but having looked at the possibilities I am a total convert.

“The people who run Vancouver do not have normal political affiliations. They are a bunch of business-savvy people who can see a vibrant green economy being a magnet for new business and forward-looking people. They are neither Labour nor Conservatives, but new progressives.”

Sylvester works at the Simon Fraser University Centre for Dialogue’s Renewable Cities Initiative, one of a number of organisations that aim to bring cities together to tackle climate change, because many local leaders believe that governments do not have the political will to do so.

Among those supporting the conference is the United Nations Environment Programme, which has its own campaign to green cities. − Climate News Network

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Major attraction of fjords is as carbon ‘graveyards’

Major attraction of fjords is as carbon ‘graveyards’

The splendour of fjords is widely admired, but scientists say they are also carbon sinks that play an important role in regulating Earth’s climate.

LONDON, 12 May, 2015 − Fjords, those dramatic narrow inlets in mountainous coastlines, are more than just beauty spots. New research shows that they are also major repositories of organic carbon, and therefore a vital part of the planet’s climate system.

Although they cover only 0.1% of the surface area of the oceans, they serve as graveyards for 18 million tonnes of organic carbon annually − 11% of all the marine carbon buried globally each year.

Richard Smith, an organic geochemist at Global Aquatic Research in New York, and colleagues report in Nature Geoscience that they analysed 573 surface samples and 124 sediment cores from nearly every fjord system in the world. These include Norway, Sweden, Greenland, Scotland, Svalbard, Western Canada, Alaska, Chile, New Zealand and Antarctica.

Sediment accumulation

Organic carbon is – or once was – plant tissue fashioned by photosynthesis from atmospheric carbon dioxide. And fjords, which are narrow, deep estuaries formed at high latitudes during glacial periods, are sites of sediment accumulation, serving as traps for all the organic carbon that flows into them.

Great rivers with magnificent deltas and estuaries also bear huge quantities of organic carbon, but much of this gets back into carbon dioxide form and is released into the atmosphere before it gets to the open sea.

But fjords, protected from ocean disturbance, become repositories for vast quantities of eroded material and landslips washed down the steep mountain sides. Because the fjords are so deep, the organic carbon is buried in a way that prevents most of it from being recycled.

The calculation is that fjords may play an important role in moderating atmospheric carbon dioxide levels during the advance and retreat of glaciers.

When the glaciers advance, much of the buried carbon would be pushed out onto the continental shelf and start turning back into greenhouse gas, eventually to warm the planet and slow the glaciation process.

During a glacial retreat, such as the present, the inlets become stores of organic carbon, preventing temperatures from rising too fast.

Piece of the puzzle

To understand climate, scientists must first account for all the elements that drive the climate machine. The carbon cycle – the traffic of carbon between air and living things and rocks and water – is a vital part of this machine, and the scientists now have yet another piece of the puzzle in place.

“In essence, fjords appear to act as a major temporary storage site for organic carbon in between glacial periods,” says one of the report’s authors, Candida Savage, a marine ecologist at the University of Otago in New Zealand.

“This finding has important applications for improving our understanding of global carbon cycling and climate change.” – Climate News Network

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Seas generate rising tide of renewables ideas

Seas generate rising tide of renewables ideas

The EU says it is time for tides to provide energy for Europe from the Atlantic and end reliance on the burning of polluting fossil fuels.

LONDON, 11 May, 2015 − A race is on worldwide to harness the tides and waves for electrical power, with more than 100 different devices being tested by companies hoping to make a commercial breakthrough.

And a new report from the European Union’s Joint Research Centre expresses confidence that the Atlantic Ocean will soon be an important contributor to the continent’s energy mix.

It adds that many other countries with big tidal ranges and long coasts are also banking on this form of renewable energy to help reduce fossil fuel use.

For years, it has been predicted that the vast quantities of energy available in the oceans would be harnessed by human ingenuity to provide without the need for burning fossil fuels, but progress has been slower than expected.

Different techniques

While it has proved possible to generate  electricity with many different techniques, scaling these up into large-scale power stations to supply the electricity grid has not so far been economic.

The two most promising basic ideas are to use the currents and the build-up of water at each tide to drive turbines to make electricity, or to convert the power in wave motions to energy.

In Europe, the countries with Atlantic Ocean coastlines – such as the UK, Ireland, France, Spain, Portugal, Denmark, the Netherlands and Norway – are all developing technologies. And in 2014, the EU launched what it called its Blue Energy Action plan to finance and encourage development. The latest report details progress so far.

Most of the technologies are not new ideas, but the trick is turning a demonstration model into a viable power station.

The one exception is tidal energy in the form of a barrage across a river, which has been in use for years.

The best known is the 240 megawatt (MW) La Rance tidal barrage in France, operating successfully since 1966. Another 254 MW tidal plant has opened in Sihwa in South Korea, and other barrages producing at total 2,680 MW are planned worldwide − although  many  have proved controversial because of their  effects on fish and birds.

Tidal lagoons − reservoirs that stand in an estuary or close to the shore, and which fill and then empty with each tidal cycle − have  now won much more favour, and one is  being developed in Swansea Bay in south Wales.

The worldwide potential of this technology is estimated at 80 gigawatts (GW), or the equivalent of 80 large coal-fired power stations.

Already in successful operation at some sites, but yet to be scaled up to full commercial development, are underwater turbines − similar to wind turbines − that use the energy in tidal streams to make electricity.

In Europe, these devices will be viable in countries with high tides and strong tidal streams − particularly France, Ireland, Norway and the UK, but also  in some parts of Belgium, Italy and the Netherlands. These are believed to offer  the highest net potential contribution  to the European energy system, according to the report.

The first large-scale tidal array is being built in the Pentland Firth, off northern Scotland. It will provide power to 175,000 homes.

New connections

Like the deployment of wind farms, potential tidal power arrays are often in remote locations far from cities. The report points out that these technologies will require new grid connections and integration into the European grid to get most value from them.

A new generation of devices not placed on the sea bed, but either floating like kites on a string or operating from platforms, is under development. Their advantage is that they avoid the cost of being built on the sea bed, and can also  exploit the greater strength of the tides nearer the surface of the sea.

Some of the materials being used to build devices to withstand the power of the sea, and the methods that are being used, are being kept secret for commercial reasons, but they have some of the biggest companies in Europe as their backers.

The commercial advantage of tidal devices is that the tides are predictable years in advance

Another new generation of micro-turbines, owned by coastal communities and anchored offshore to take advantage of tidal flows, is under development. These could give communities isolated from the grid their own power source, like solar panels do in remote parts of Africa and Asia.

There are an estimated 100 companies developing tidal energy devices worldwide, half of them  in the EU, where many are supported by development grants. Four tidal energy stations are already in operation in Europe, and another 31 are expected to be completed by the end of 2016. Many more are in the planning stage.

The commercial advantage of tidal devices is that, unlike some other forms of renewable energy, the tides are predictable years in advance. Wave power, on the other hand, suffers because of its unpredictability and the need to make devices robust enough to stand up to the battering  they receive.

Potential supply

That has not stopped a large number of development projects being built, principally because the potential energy supply is vast –  30 times higher than tidal energy.

Some devices have already been operating successfully for 10 years, producing regular quantities of electricity, but they were built as demonstration models and not on a commercial scale.

Building structures large enough to produce a regular power supply at a cost that could be commercial has proved elusive, but the report describes a number of devices that are close to achieving commercial viability.

There are at least nine different technologies using wave power, and 170 wave energy developers worldwide.

The report also discusses technologies that use the different gradients of salinity in the sea to produce power, and the different water temperatures to generate energy.

However, it argues that both these ideas, while viable in theory, are further away from commercial operation in Europe than tidal stream or wave power. – Climate News Network

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Plant growth may speed up Arctic warming

Plant growth may speed up Arctic warming

Arctic plants may absorb more greenhouse gases as the region warms – but scientists say this could intensify the warming rather than moderate it.

LONDON, 10 May, 2015 – Green may not automatically mean innocent or planet-friendly after all. Korean and German scientists have identified a mechanism that could encourage plants to take up more carbon dioxide – and at the same time amplify Arctic warming by 20%. This counter-intuitive finding is published in the Proceedings of the National Academy of Sciences.

Jong-Yeon Park of the Max Planck Institute for Meteorology and colleagues have been looking at the role of phytoplankton, those tiny marine plants that flourish around land masses, exploit the nutrients that flow from rivers and turn the blue ocean sea-green. Like any grass or shrub or tree, they exploit sunlight and employ photosynthesis to soak up atmospheric carbon dioxide.

So as the Arctic Ocean warms, because of increasing emissions of carbon dioxide from the burning of fossil fuels, the ice melts, the blue sea water absorbs more sunlight, and the green things get a chance to grow and soak up some of that greenhouse gas as organic carbon in plant tissues. This is what engineers call negative feedback.

But it may not work like that. The scientists matched up a model of the climate system with a model of the ecosystem and did all the sums again. And they found that instead of reducing warming, an explosion of phytoplankton growth could actually amplify it.

More warming

If the seas warmed and the ice melted, then the overall albedo – the reflectivity of the Arctic – would be changed. More high energy solar radiation would get into the sea, and the phytoplankton harvest would be greater and go on for longer.

But more phytoplankton would mean more biological activity, which would directly warm the surface layer of the ocean, “triggering additional positive feedbacks in the Arctic, and consequently warming the Arctic further,” the authors warn.

“We believe that, given the inseparable connection of the Arctic and global climate, the positive feedback in Arctic warming triggered by phytoplankton and their biological heating is a crucial factor that must be taken into consideration when projecting future climate changes,” said Jong-Seong Kug, a professor at Pohang University of Science and Technology in Korea.

Science like this is a reminder that the climate system is a subtle and complex machine driven by sunlight, atmosphere, water – and carbon. A British team has warned that rainforests could in fact be emitting much more carbon than climate modellers have accounted for. That’s because they haven’t allowed for all of the dead wood.

“A large proportion of forests worldwide are less of a sink and more of a source”

Marion Pfeifer of Imperial College and colleagues report in Environmental Research Letters  that they surveyed a large area of forest in Malaysian Borneo to make their calculations.

Pristine, untouched forest is rare. Most forests provide an income for someone, and increasingly parts of the great forests are exploited by loggers and planters. In untouched forests, dead wood makes up less than 20% of the biomass. Dr Pfeifer and her colleagues found that in partially-logged forests, the dead wood could account for 64% of the biomass.

Details such as this could send climate modellers back to the drawing board. That is because the great riddle of climate science is: where does all the carbon go? The assumption has been that forests are “sinks” that collect atmospheric carbon. But that depends on the forest.

“I was surprised by how much of the biomass dead wood accounted for in badly-logged forests. That such logged forests are not properly accounted for in carbon calculations is a significant factor. It means that a large proportion of forests worldwide are less of a sink and more of a source, especially immediately following logging, as carbon dioxide is released from dead wood during decomposition,” Dr Pfeifer said.

“Selectively-logged tropical forests now make up about 30% of rainforests worldwide. That means such global calculations are wrong at least 30% of the time.” – Climate News Network

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