Deep concerns as climate impacts on Gulf Stream flow

Deep concerns as climate impacts on Gulf Stream flow

Ocean scientists find evidence of an increasing slowdown in the Atlantic’s “invisible river” that could seriously affect weather and sea levels in the US and Europe.

LONDON, 25 March, 2015 − Climate scientists have once again confirmed an alarming slowdown in the circulation of the Atlantic Ocean − the process that drives the current that warms Europe, and powers the planetary climate.

And this time, they are prepared to say that the changes are recent − and may be linked to global warming.

The Atlantic Conveyor is a great invisible river that flows in two directions at the same time. The equatorial surface waters − warm, and therefore less dense − flow towards the north in the form of the Gulf Stream. Around Greenland, the denser and colder Arctic waters sink to the ocean bottom and begin their progress towards the south.

It is the difference in temperatures that maintains the turnover and keeps the climate engine going.

As a consequence, the two-way traffic of warm and cold water redistributes heat around the planet and keeps Britain and maritime Europe in relatively mild conditions.

But as global average temperatures rise, and the Greenland ice sheet melts, ocean scientists have warned that the speed of the ocean turnover could be put at risk.

Greater weakening

Stefan Rahmstorf, an ocean physicist at the Potsdam Institute for Climate Impact Research in Germany, is lead author of a report in Nature Climate Change that says they now have evidence of a slowdown during the 20th century, and greater weakening since the first alarms 40 years ago about the possible effects of greenhouse emissions.

“It is conspicuous that one specific area in the North Atlantic has been cooling in the past hundred years, while the rest of the world heats up,” Professor Rahmstorf says. “Now we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970.”

The paradox of the Atlantic current is that, in a warmer world, it could slow down or halt, which would deliver uncomfortable consequences for maritime Europe.

Fears of such an effect provided the scenario for the 2004 climate disaster movie, The Day After Tomorrow, which predicated a frozen Britain and a glaciated US.

“Now we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970”

No such extreme outcome was ever likely, but the Gulf Stream certainly makes a big difference to Britain. A former UK chief scientist once calculated that it delivered 27,000 times the warmth that Britain’s power stations could supply and, as a consequence, the UK is on average 5°C warmer than it might be, given its latitude.

Strength of current

At a number of points in the last two decades, researchers have wondered about the strength of the Atlantic current, but since systematic oceanographic record-keeping began only relatively recently, they had no way of distinguishing between a natural oceanic cycle and real change.

So the Potsdam team used all available data, and “proxy temperatures” derived from ice-cores, tree-rings, coral, and ocean and lake sediments, to reconstruct the story of the Atlantic current − and, in particular, the phenomenon called the Atlantic meridional overturning circulation (AMOC) − for the last 1,000 years.

The changes happening now have no precedent since 900 AD, they say. And the increasingly rapid melting of the Greenland icecap – bringing an increased flow of water that is less saline and also less dense, and therefore less likely to sink − could disturb the circulation.

The consequences of all this could, they say, “contribute to further weakening of the AMOC” in the coming decades.

Atlantic Conveyor: a graph of the Atlantic Meridional Overturning Circulation (AMOC). Image: Stefan Rahmstorf/PIK

Atlantic Conveyor: a graph of the Atlantic Meridional Overturning Circulation (AMOC).
Image: Stefan Rahmstorf/PIK

This is not the first such alarm. The same weakening was identified last year, but at the time researchers could not be sure they were not looking at a natural fluctuation.

Now they are sure, and they suspect that the cooling of the north Atlantic that they now observe is even stronger than most computer simulations have so far predicted.

“Common climate models are underestimating the change we’re facing, either because the Atlantic overturning is too stable in the models or because they don’t properly account for the Greenland ice sheet melt, or both,” says one of the co-authors, Michael Mann, professor of meteorology at Pennsylvania State University in the US.

Climate predictions

“That is another example where observations suggest that climate model predictions are in some respects still overly-conservative when it comes to the pace at which certain aspects of climate change are proceeding.”

Another of the authors, Jason Box, professor of glaciology at the Geological Survey of Denmark and Greenland, adds that “the human-caused mass loss of the Greenland ice sheet appears to be slowing down the Atlantic overturning − and this effect might increase if temperatures are allowed to rise further”.

The stakes are high. If the Atlantic conveyor system continues to weaken, ocean ecosystems will change, fishing communities will be affected, and some coastal cities – such as New York and Boston in the US − could be hit by additional regional sea level rises.

The 2004 Hollywood version – promoted with a huge poster of New York’s Statue of Liberty all but covered by ice – is not likely to happen. But if the ocean circulation weakens too much, there could be a relatively rapid and difficult-to-reverse change in the world’s climate system.

The Intergovernmental Panel on Climate Change estimates that there is a one-in-10 chance of this “tipping point” happening within the 21st century.

But the evidence from the Potsdam team is now likely to prompt other climate scientists to go back to their calculations and re-evaluate the risk. – Climate News Network

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Earth at risk in new epoch ruled by destructive humans

Earth at risk in new epoch ruled by destructive humans

Scientists warn that our fate is in our own hands as humans now control almost every aspect of the planet, on a scale akin to the great forces of nature.

LONDON, 21 March, 2015 − Nature has been replaced by humans as the driving force behind changes on the planet − and we need to take urgent action if we are to avoid our own destruction.

This is the view of two scientists – including a Nobel prize winner − who support the theory that the planet has entered a new Anthropocene epoch that has succeeded the Holoscene, the  current geological warm period that began at the end of the ice age 11,500 years ago.

It is not a new concept − the name Anthropocene was coined 15 years ago by American ecologist Eugene F. Stoermer to describe how humans had taken over from nature to decide the planet’s future − but the authors of a new paper believe they have shown that it is now a frightening reality.

Paul Cruzten, the 1995 Nobel Laureate in Chemistry, from the Max Planck Institute for Chemistry, in Mainz, Germany, and Stanislaw Waclawek, researcher in the Department of Nanomaterials in Natural Sciences at the Technical University of Liberec, Czech Republic, make their case in the paper published in the new Chemistry-Didactics-Ecology-Metrology.

Human footprint

The article claims that the negative impact of the human footprint ensures a gradual destruction of the Earth, “Our survival fully depends on us,” Cruzten says.

The scientists claim that there is overwhelming evidence that what they term “man, the eroder” now transforms all Earth system processes. They offer this list in support of their argument:

  • Excessively rapid climate change, so that ecosystems cannot adapt.
  • The Arctic ocean ice cover is thinner by approximately 40% than it was 20-40 years ago.
  • Ice loss on land is causing the rising sea levels.
  • Overpopulation (a fourfold increase in the 20th century alone).
  • Increasing demand for freshwater.
  • Releases of nitrogen oxide into the atmosphere, resulting in high surface ozone layers.
  • Loss of agricultural soil through erosion.
  • Loss of phosphorous (dangerous depletion in agricultural regions).
  • Melting supplies of phosphate reserves (leading to serious reduction in crop yield).

The paper begins: “Humankind actions are exerting increasing effect on the environment on all scales, in a lot of ways overcoming natural processes.

“During the last 100 years, human population went up from little more than one billion to six billion, and economic activity increased nearly 10 times between 1950 and the present time.”

Industrial activity

In a series of graphics, the two scientists show how the growth of population, industrial activity and, above all, the release of greenhouse gases are causing chaos in nature and threatening our existence.

The paper says: “Taking into account these and many other major and still growing footprints of human activities on Earth and atmosphere, without any doubt we can conclude that we are living in new geological epoch named the Anthropocene.”

Cruzten warns: “This ensures a gradual destruction of the Earth. For the sake of our children and grandchildren, we must change course.” – Climate News Network

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Powerful wind blows through US energy sector

Powerful wind blows through US energy sector

Wind power in the US now generates enough electricity for more than 11 million homes, but it needs government support for further growth.

LONDON, 20 March, 2015 − The wind turbines are turning across America, and a major report by the US Department of Energy (DOE) says the wind energy sector now supplies 4.5% of the nation’s electricity.

Given the right energy policies and investment in infrastructure, that figure could increase to 10% by 2020 and to 35% by 2050, the DOE predicts.

That will not only benefit tens of thousands of workers who will be employed in one of the US’s fastest-growing industries. It’s also good news for the climate, and will help preserve increasingly precious water supplies.

“Deployment of wind technology for US electricity generation provides a domestic, sustainable and essentially zero carbon, zero pollution and zero water-use US electricity resource,” the DOE says.

Impressive growth

The rate of growth of wind power in the US has been impressive. In 2011 alone, nearly 3,500 turbines went up across the country. And the Natural Resources Defence Council says that a typical 250 megawatt wind farm − around 100 turbines − will create 1,073 jobs over the lifetime of the project.

The DOE says costs of wind power are dropping, while reliability and other issues are being sorted out. “Wind generation variability has a minimal and manageable impact on grid reliability and costs,” the report says.

Texas is the top wind power state, followed by Iowa, California and Oklahoma. At the end of 2013, the US had 61 gigawatts (GW) installed − up from 25 GW in 2009.

The aim is to increase those figures to 113 GW by 2020, to 224 GW by 2030, and to more than 400 GW by 2050.

The DOE says that if these plans are realised, the emission into the atmosphere of more than 12 gigatonnes of climate changing greenhouse gases (GHG) will be avoided.

“Pairing this homegrown resource with continued technology innovation has made the US the home of the most productive wind turbines in the world”

“Wind deployment can provide US jobs, US manufacturing and lease and tax revenues in local communities to strengthen and support a transition towards a low-carbon US economy,” the report says.

The trouble is that there is considerable resistance to wind power in parts of the political establishment. The DOE report – while not directly accusing Washington of standing in the way of progress on wind − does say that “new tools, priorities and emphases” need to be set in place in order to achieve wind energy targets.

These include an urgent need for a large-scale infrastructure programme in order to build wind power transmission lines.

The American Wind Energy Association, (AWEA), body that represents the industry, calculates that about 900 miles of transmission lines need to be put in place each year up to 2050 if the DOE is to achieve its wind power goals.

Tax policies to encourage wind development are also required. A special Wind Production Tax Credit (PTC), which effectively gave subsidies to the wind industry of about $13 billion a year, was brought in 1992.

Receive subsidies

But when the tax credit came up for renewal in 2012, it was not retained in the tax code, and finally lapsed at the end of 2013, although the oil, gas, fracking and coal industries – all major GHG emitters − have continued to receive subsidies.

Political analysts say there is little likelihood that the PTC will be renewed by a legislature controlled by the Republican party – which is generally opposed to giving financial incentives to the renewable energy sector.

The elimination of tax breaks initially slowed growth in the construction of wind energy facilities, but the industry remains upbeat and says investors are still putting money into projects.

“The US is blessed with an abundant supply of wind energy,” the AWEA says. “Pairing this homegrown resource with continued technology innovation has made the US the home of the most productive wind turbines in the world.” – Climate News Network

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Old King Coal is sick – but not yet dying

Old King Coal is sick – but not yet dying

The building of coal-fired power stations across much of the world is declining, but the trend is not enough to avert the risk of climate change reaching dangerous levels.

LONDON, 17 March, 2015 − A global investigation into every coal-fired power plant proposed in the last five years shows that only one in three of them has actually been built.

Researchers say that for each new plant constructed somewhere in the world, two more have been shelved or cancelled. They say this rate is significantly higher in Europe, South Asia, Latin America and Africa. In India, since 2012 six plants have been cancelled for each one built.

Coal use has also shrunk significantly. In China it fell in 2014 for the first time for 14 years, while the economy grew by 7.3%. From 2003 to 2014 the amount of coal-fired generating capacity retired in the US and the EU exceeded new capacity by 22%.

But it is more than simply a question of the number of plants being built (or not). The report says:”The amount of new coal-fired generating capacity in the proposal pipeline worldwide dropped from 1,401 GW in 2012 to 1,080 GW in 2014, a 23% decline” (one GW, or gigawatt, would supply enough electricity for 750,000 to 1m typical US homes).

Against this, concentrations of planned new coal plants can still be found in Turkey, Vietnam, Indonesia, Poland, some Balkan countries and Japan. Germany is one country which continues to burn large quantities of coal, including lignite. And global coal consumption grew by 3% in 2013, well below the 10-year average of 3.9%, but still the fastest-growing fossil fuel.

Contracting market

Ted Nace of CoalSwarm, a network of researchers into coal’s impacts and alternatives to it, said: “What’s striking is how quickly the business climate has turned against coal since 2012. Because these projects require large capital outlays, they’re vulnerable to rising perceptions of risk.”

The report, Boom and Bust: Tracking The Global Coal Plant Pipeline, by the Sierra Club and CoalSwarm, details the findings of research into every proposed coal-fired power plant worldwide since 2010. The data in the report will be continuously updated on the Global Coal Plant Tracker website.

The report’s findings suggest strongly that the market for coal is contracting, but the authors acknowledge that the trend will have to accelerate if the world is to avoid crossing the internationally agreed threshold which is thought able to prevent dangerous climate change.

The International Energy Agency is among those warning that, to keep global warming from rising beyond the agreed maximum of 2°C above pre-industrial levels, no more than one-third of proven reserves of fossil fuels can be burned before 2050.

“Existing global coal-fired power plant capacity will already swallow four-fifths of the 2°C carbon budget over its lifetime”

A recent report from University College London found that, globally, to stay within 2°C, 82% of coal reserves must be left underground, 49% of gas and 33% of oil reserves. Boom and Bust argues that, even if the trend of two coal plant proposals halted for every plant built continues, the remaining one-third will account for nearly all of the greenhouse gases that can be emitted before climate change crosses the 2°C threshold.

Luke Sussams, senior researcher of the Carbon Tracker Initiative, said: “Existing global coal-fired power plant capacity will already swallow four-fifths of the 2°C carbon budget over its lifetime, leaving no room for burning the world’s oil and gas.

“This fundamental contradiction means investors must assess their exposure to coal plants that are most at risk of becoming stranded in a carbon-constrained world, and steer clear of funding any new coal plants altogether.”

Analysis by Carbon Tracker has also identified major financial risks for investors in coal producers around the world, with $112 billion worth of investments in future coal mine expansion and development that will not be needed under lower demand forecasts.

The Sierra Club and CoalSwarm say that, as attention focuses on the UN climate negotiations in Paris in December, new and existing coal plants must be phased out, with OECD countries giving a lead. Countries should undertake to end subsidies and policies that favour coal and focus instead on clean energy.

The report says that not only is coal the most carbon-intensive way of generating electricity, but the fine-particle pollution it causes kills an estimated 800,000 people prematurely every year, with China thought to account for 670,000 of these deaths and India 80-115,000. − Climate News Network

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Serious doubts over Europe’s GHG reduction target

Serious doubts over Europe’s GHG reduction target

Europe has made substantial progress in cutting greenhouse gas emissions, but its long-term reduction aims look unachievable, says a new report.

LONDON, 9 March, 2015 − The 28 countries of the European Union (EU) have set themselves a collective target of cutting emissions of climate-changing greenhouse gases (GHGs) by between 80% and 95% by 2050, but  a major report just released says there’s little hope of achieving that goal.

Every five years, the European Environment Agency (EEA) produces a comprehensive study, and the latest says projected declines in GHG emissions are not nearly enough to reach the long-term target of decarbonising most of Europe’s economy by mid-century.

The report says there has been considerable progress in recent years on reducing Europe’s GHG emissions to 19.2% below 1990 levels. while, at the same time, gross domestic product across the EU has increased by 45%. EU per capita emissions fell from 11.8 tonnes of CO2 equivalent in 1990 to 9 tonnes in 2012.

The trouble is that this progress is very unlikely to be maintained over the long term unless the entire EU economy is revamped and there are very substantial investments in renewables.

Hard part ahead

The cut in GHG emissions was largely achieved through economic restructuring in eastern Europe following the collapse of the old Soviet Union and associated states. Polluting energy and industrial plants were closed, and agricultural practices modernised.

The 2008 economic crisis also caused a dip in emissions, while EU policies aimed at achieving greater energy efficiency have also played an important role in reducing emissions.

That, in many ways, was the easy part. Now comes the big challenge: in order to achieve its long-term emissions reduction objective, Europe needs a wholesale reorganisation of its economy, says the EEA, and also needs to become less resource-hungry.

Fossil fuels still dominate energy production, accounting for 75% of energy supply in 2011 − the most recent year for which comprehensive statistics are available.

Progress achieved

“The EU will need to accelerate its implementation of new policies, while restructuring the ways that Europe meets its demand for energy, food, transport and housing,” the report says.

Short-term goals can be achieved, says the EEA, and the EU is on track to meet its target of producing 20% of its energy from renewable sources by 2020. Renewables accounted for 11% of EU energy production in 2012 – up from 4% in 1990.

It is a similar story across much of the European environment. Progress has been made over recent years in improving water systems, waste collection and recycling, and in rehabilitating some ecosystems.

“In many parts of Europe, the local environment is arguably in as good a state today as it has been since the start of industrialisation,” the report says. “Reduced pollution, nature protection and better waste management have all contributed.”

Worsening air

At the same time, what the report refers to as Europe’s natural capital is being seriously degraded by the activities of agriculture, fisheries, industries and  tourism. Urban sprawl is also having a negative impact.

In some regions, ecosystems are in a dire state, and the EU is not on track to meet its 2020 target on halting biodiversity loss.

Air quality is a particular concern.  The EEA estimates that more than 400,000 people in Europe died prematurely in 2011 due to breathing in toxic fumes. In some areas, air quality is getting worse, not better. And land is under severe pressure.

The report says that “loss of soil functions, land degradation and climate change remain major concerns, threatening the flows of environmental goods and services that underpin Europe’s economic output and well-being”. −  Climate News Network

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Poorest nations seek US-EU lead on climate deal

Poorest nations seek US-EU lead on climate deal

Hopes that this year’s UN climate talks will produce an effective global treaty to cut emissions may rest on richer countries setting far more ambitious targets.

LONDON, 7 March, 2015 – Quamrul Chowdhury, a lead negotiator for the Least Developed Countries bloc at UN climate talks, is concerned that the US and European Union are failing to give the lead they should on emissions reductions.

Visiting the UK to speak at universities in Oxford and London, he told the Climate News Network: “With the US and the EU, we expect both to raise their level of ambition to mitigate climate change. Only if they take the lead can we reach consensus.”

Chowdhury, an energetic and familiar figure at the annual UN climate conferences, said of this year’s treaty negotiations in Paris in December: “I’m optimistic, but it’s going to be a Herculean task. We’ll have to make a lot of compromises and collapse our red lines if we are to achieve an ambitious, robust treaty.”

Binding target

The US plans to reduce its emissions by 26%-28% from their 2005 levels to achieve “economy-wide reductions in the order of 80% by 2050”. The EU plans a binding, economy-wide domestic reduction target for 2030 of at least 40% from 1990 levels.

But Chowdhury believes this is not enough, and that both must go further. “This range of ambition will not add up to an aggregate level that takes us to the internationally-agreed goal of preventing global average temperature rise exceeding 2°C, much less 1.5°C,” he said.

“We need to cut emissions faster than that. If the Americans and Europeans don’t do so, other countries will not be ready to raise their level of ambition.”

The LDCs insist that the developed world must act first − an argument that has preoccupied many previous negotiations.

“The developed countries are the leaders − it’s their responsibility,”  Chowdhury said. “If they can give that lead, other countries will follow. We’ve contributed an insignificant amount of greenhouse gases.

We can’t afford not to agree a legally-binding treaty . . . If we fail, the most vulnerable countries will be the victims

“The US and the EU are doing quite well, but we need more ambition or else the gap will be so huge. We have to move faster in the short time left to negotiate, otherwise the most vulnerable countries’ situation will be catastrophic.”

The LDCs, many of them already bearing the brunt of the climate onslaught, are prepared to give ground for the sake of an agreement.

“We always want to make compromises,” Chowdhury said. “We’ve shown flexibility in the past, and we’re ready to do so now − to go the extra mile. Billions of people are on the receiving end of climate change.”

However, it’s not clear whether the LDCs will cut their own emissions. Chowdhury said: “If we reach an agreement in Paris, there will be from us what some call a commitment, and others describe as an intention, to make cuts.

“There are so many ifs and buts, though, so much mathematics. We agree in principle to cuts, but we can’t say at this stage what they’ll be.

Effective treaty

“For the effective treaty we need, the means of implementation are essential. We’ll need money to pay for technology transfer, capacity building and helping our economies through the transition of adapting. The money will need to be predictable, new, additional and easily accessed.”

The LDCs won’t rush to judgement in the Paris talks. Chowdhury said: “They’ll be a success, first, if we get a treaty with raised ambition. But while the process of implementing that treaty will start in January 2016, the end results won’t be achieved till 2020.”

Some commentators say that hopes for Paris are high because countries will be asked to meet lowered expectations − in other words, that any treaty attainable won’t offer much.

Chowdhury sees it differently. “We can’t afford not to agree a legally-binding treaty in December”, he said. “If we fail, the most vulnerable countries will be the victims. We shall have to suffer much more, and we can’t afford any longer to let that happen.” − Climate News Network

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Seeing is believing: scientists trace greenhouse effect

Seeing is believing as scientists trace greenhouse effect

High-precision field instruments in the US have provided the first real-time “action shots” of the increasing impact of CO2 on global warming.

LONDON, 28 February, 2015 − Government scientists in the US say they have directly observed for the first time the greenhouse effect in action, while monitoring the way carbon dioxide in the Earth’s atmosphere absorbed increasing amounts of thermal radiation from the surface.

Their measurements, taken over a period of 11 years in Alaska and Oklahoma, confirm predictions made more than 100 years ago, and repeatedly examined: there is a greenhouse effect, and the greenhouse gas that most helps the world warm is carbon dioxide.

The phenomenon is known in climate science shorthand as radiative forcing, which happens when the Earth absorbs more energy from solar radiation than it emits as thermal radiation back into space.

The sun shines through the greenhouse gases as if they were glass, and warms the rocks. The rocks emit infra-red waves, but the transparent gases now keep the heat in, as if they formed the glass roof of a greenhouse.

Radiative forcing

Although this radiative forcing has been assessed, quantified, modelled, predicted and worried about, the scientists say this is the first time it has been formally tested outside, in the open air.

Daniel Feldman, geological project scientist at the Lawrence Berkeley National Laboratory in California, and colleagues report in Nature that the increase in temperatures over the period adds up to two-tenths of one Watt per square metre per decade.

And this small notch in the thermometer record is linked to an increase of 22 parts per million in carbon dioxide levels in the atmosphere in the decade. Much of this extra CO2 comes from the burning of fossil fuels.

The finding is no surprise. For 30 years, climate scientists have recorded a steady average annual rise in planetary temperatures.

“We see, for the first time in the field, the amplification of the greenhouse effect because there’s more CO2 in the atmosphere . . .”

They expected it, and they predict that unless the world makes a switch from coal, oil and natural gas to solar, wind, water and wave energy, or biofuels, or nuclear or geothermal power sources, global average temperatures will go on rising inexorably. The glaciers and icecaps will melt, sea levels will rise, and climate extremes – especially heat waves, and probably floods – will also increase.

So the Nature study is just a piece of tidying up. But it is an illustration that the calculations can be confirmed by direct measurement − by catching carbon dioxide in the act, so to speak. Laboratory measurements said it would happen, computer simulations said it would happen, and now direct measurement completes the picture.

Solar radiation

“We see, for the first time in the field, the amplification of the greenhouse effect because there’s more CO2 in the atmosphere to absorb what the earth emits in response to incoming solar radiation,” Dr Feldman says.

“Numerous studies show rising atmospheric CO2 concentrations, but our study provides the critical link between those concentrations and the addition of energy to the system, or the greenhouse effect.”

The study is built on 3,300 measurements in Alaska and 8,300 in Oklahoma, under clear skies and using high-precision instruments.

Carbon dioxide is not the only greenhouse gas: water vapour also plays a role, along with oxides of nitrogen and methane or natural gas.

But the study was powerful enough to isolate carbon dioxide’s contribution, and even register a dip in this radiative forcing early every year as the green shoots of spring begin to take up the greenhouse gas to build the new leaves and stems that nourish a hemisphere.

The authors conclude that the results confirm theoretical predictions, and provide empirical evidence of just what rising CO2 levels can do. – Climate News Network

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Acid attack on algae damages ocean ecosystem

Acid attack on algae damages ocean ecosystem

Increasing acidity in the Southern Ocean is having a serious effect on the growth of a small but hugely important food source for marine life.

LONDON, 27 February, 2015 − As the planet’s oceans become more acidic, the diatoms − a major group of alga − in the Southern Ocean could grow more slowly.

Nobody expected this. And since tiny, single-celled algae are a primary food source for an entire ocean ecosystem, the discovery seems ominous.

Bioscientist Clara Hoppe and colleagues from the Alfred Wegener Institute [http://www.awi.de/en/home/]at the Helmholtz Centre for Polar and Marine Research in Bremerhaven, Germany, report in the journal New Phytologist that they tested the growth of the Antarctic diatom Chaetoceros debilis under laboratory conditions.

They used two levels of pH – which is an indicator of acidity – and they exposed their tiny volunteers to constant light and to changing light, providing both standard laboratory conditions and lighting levels that approximated to the real world.

Plant growth

In the unblinking glare of light, the diatoms responded well. Their growth levels were consistent with an assumption that more dissolved carbon dioxide – which makes the waters more acidic – would in effect fertilise plant growth.

Under conditions of changing light, however, it was a different story. The algae grew more slowly, which suggests that the oceans could become less efficient at removing carbon from the atmosphere, and perhaps less valuable as a primary food source for the creatures that teem in the Antarctic waters.

“Diatoms fulfil an important role in the Earth’s climate system,” Dr Hoppe says. “They can absorb large quantities of carbon dioxide, which they bind before ultimately transporting part of it to the depths of the ocean.

“Once there, the greenhouse gas remains naturally sequestered for centuries.”

Previous research into the steady acidification of the oceans has tended to concentrate on the consequences for coral reefs,  fisheries, and tourism, but not on the impact on plant life in the seas.

Since carbon dioxide acts as a fertiliser, higher levels dissolved in the water might stimulate more growth.

“We now know that when the light intensity constantly changes, the effect of ocean acidification reverses”

But growth depends not just on more carbon dioxide, but also on reliable sunlight. In the stormy southern seas, this is not steadily supplied.

Dr Hoppe says: “Several times a day, winds and currents transport diatoms in the Southern Ocean from the uppermost water layer to the layers below, and then back to the surface – which means that, in the course of a day, the diatoms experience alternating phases with more and with less light.”

Her co-author, marine biogeochemist Björn Rost, from the Alfred Wegener Institute, says: “Our findings show for the first time that our old assumptions most likely fall short of the mark. We now know that when the light intensity constantly changes, the effect of ocean acidification reverses.

“All of a sudden, lower pH values don’t increase growth, like studies using constant light show. Instead, they have the opposite effect.”

The implication is that, at certain intensities, the photosynthesis chain breaks down. The point at which light becomes too much light is more quickly reached in waters that are more acidic.

Like all such research, the finding has limitations. It applies to one species of single-celled creature in the waters of one ocean, and the tests were in a laboratory on a small scale, and not in a turbulent ocean rich in life. The Alfred Wegener team will continue their studies.

But in the real world, coastal communities in 15 US states could be at long-term economic risk, as ocean acidification starts to take its toll on the commercial oyster fisheries.

Julia Ekstrom, then of the Natural Resources Defense Council and now director of the Climate Adaptation Programme at the University of California, Davis, and George Waldbusser, assistant professor of ocean ecology and biogeochemistry at Oregon State University report with colleagues, in Nature Climate Change, on an unholy mix in the oceans.

Fisheries at risk

They say that a combination of rising greenhouse gas levels, more acid waters, polluted rivers, and upwelling currents put at risk mollusc fisheries from the Pacific Northwest, New England, the Mid-Atlantic states and the Gulf of Mexico – affecting the shellfish industry that is worth at least $1bn to the US.

Oyster larvae are sensitive to changes in ocean water, and more likely to die as pH levels shift towards the acidic.

But acidification is not the only source of stress, as nitrogen-rich nutrients and chemical pollutants cascade from the land into the rivers, and wash through estuaries and fish hatcheries on the coast.

Things can be done. Scientists have been looking at ways in which the industry might be able to adapt to change. But how well the oyster stock can adapt in the long term remains problematic.

“Ocean acidification has already cost the oyster industry in the Pacific Northwest nearly $110 million and has jeopardised about 3,200 jobs,” Dr Ekstrom says.

And Dr Waldbusser adds: “Without curbing carbon emissions, we will eventually run out of tools to address the short term, and we will be stuck with a much longer-term problem.” – Climate News Network

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Satellite link puts sharper focus on ocean acidity rise

Satellite link puts sharper focus on ocean acidity rise

Global data network could provide scientists with an easy and cheaper way of finding answers to crucial questions on the oceans’ changing chemistry.

LONDON, 25 February, 2015 − Climate scientists are looking for a new perspective on the increasingly acidic oceans through a suite of satellites 700 km out in space, watching over parts of the seas that research ships cannot reach.

They report in the journal Environmental Science and Technology that thermal cameras could measure ocean temperatures, while microwave sensors could measure ocean salinity. Together, the two sets of data could help answer, cheaply and easily, questions about the chemistry of the oceans – and in particular changes in pH, the index of acidity.

Until now, researchers have depended on specialist instruments or shipboard samples to provide answers to huge questions about the oceans’ increasing uptake of carbon dioxide. Such research is costly and limited.

But ocean science has become ever more important. Each year, 36 billion tonnes of CO2 are released into the atmosphere, and about a quarter of this gets into the oceans.

Greenhouse gas

That’s a good thing: if it did not, global warming would accelerate at an even greater rate. But the same global transfer of greenhouse gas also delivers a stronger solution of carbonic acid to the oceans, and ocean acidity levels have risen by 26% over the last 200 years.

The consequences for all those sea creatures that evolved to exploit ocean chemistry to build shells or skeletons are uncertain, but the evidence so far is that changes can affect fish behaviour, shellfish reproduction, and coral growth.

The changes could almost certainly affect fisheries in the short term, and in the long term could possibly alter the continuous and vital exchanges between atmosphere and ocean that controls the climates of continents.

So marine scientists launched a Global Ocean Acidification Observing Network to assemble worldwide expertise and find new ways to monitor change.

“We are pioneering these techniques so that we can monitor large areas of the Earth’s oceans”

“Satellites are likely to become increasingly important for the monitoring of ocean acidification especially in remote and dangerous waters like the Arctic,” says one of the report’s authors, Jamie Shutler, an oceanographer at the University of Exeter. UK.

“It can be difficult and expensive to take year-round direct measurements in such inaccessible locations. We are pioneering these techniques so that we can monitor large areas of the Earth’s oceans, allowing us to quickly and easily identify those areas most at risk from the increasing acidification.”

The European Space Agency’s SMOS satellite in orbit. Image: ESA

The European Space Agency’s SMOS satellite in orbit.
Image: ESA

The new approach will exploit a number of existing satellites, along with the European Space Agency’s Soil Moisture and Ocean Salinity sensor (SMOS), launched in 2009, and the US space agency NASA’s Aquarius satellite, launched in 2011.

The satellites cannot, of course, directly measure ocean pH values, but the capacity of CO2 to dissolve in water is controlled by ocean temperatures.

Salinity levels

On the other hand, salinity levels play into the capacity to form carbonates. Chlorophyll levels in the oceans also indicate the rates at which biology can exploit any of the dissolved carbon dioxide.

If the scientists have temperature and air pressure data as well, they have enough to begin to calculate the rates at which any stretch of sea might be acidifying.

Although such measurements are indirect, and involve complex mathematical calculation, the results can be checked in some places against real-time data from a network of autonomous instruments called Argo, and by shipboard laboratory studies.

But satellites are about the only way of making consistent measurements of the desolate and hostile Arctic and Indian Oceans. They could also help researchers understand the changes taking place in complex stretches of sea such as the Bay of Bengal and the Greater Caribbean.

The research is in its infancy. But the authors say that satellite studies − supported by good measurements taken directly at sea − could become a key element in understanding and assessing the acidification of the oceans. – Climate News Network

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Energy giant’s bleak outlook is 25% rise in CO2

Energy giant’s bleak outlook is 25% rise in CO2

The British-based oil and gas supermajor BP says it expects global emissions of carbon dioxide to rise by a quarter in the next 20 years.

LONDON, 24 February, 2015 − It may come as a shock, as governments ponder how to tackle climate change, to learn that the world is moving rapidly in the wrong direction.

But BP, one of the world’s six biggest oil and gas companies, says it thinks that, on present trends, emissions of CO2 will be 25% greater within two decades than they are today.

The prediction is published in BP’s Energy Outlook 2035, which it says is its best effort “to describe a ‘most likely’ trajectory of the global energy system”.

Global consumption

Some of the company’s other projections are hardly less startling. It thinks, for instance, that global energy consumption will be 37% greater by 2035 than it is today, with more than half the growth coming from India and China, and virtually all of it from countries that are not members of the OECD − the 34-member group of highly developed countries.

Global energy intensity − which measures the energy efficiency of a country’s economy − in 2035 is expected to be only half of what it was in 1995, and 36% lower than in 2013.

The lower the energy intensity is, the less it costs to convert energy into wealth. Even so, global energy use per person is projected to increase by 12%, as growing numbers of people demand higher living standards.

Renewables are expected to grow faster than any other energy source, by 6.3% annually. Nuclear power, at 1.8% a year, and hydro-electric power (1.7%) will grow faster than total energy use.

Among fossil fuels, natural gas is expected to grow fastest, with oil marginally ahead of coal. By 2035, China and India will together account for 60% of global demand for coal.

The most likely path for carbon emissions, despite current government policies and intentions, does not appear sustainable

In a guide to its Energy Outlook, BP (formerly British Petroleum) says it thinks fossil fuels will provide most of the world’s energy needs by 2035, meeting two-thirds of the expected increase in demand by then.

But it is renewables − “unconventional fossil fuels”, and gas, which is the least polluting fossil fuel − that will provide the largest share, while coal grows more slowly than any other fuel.

This, the Outlook says, will be the consequence of slowing industrialisation in emerging Asian economies and of more stringent global environmental policies.

To that it might have added the growing pressure for investors to steer clear of putting their money into fossil fuels, for fear that they could be at risk from a robust and rigorously-enforced global agreement on cutting greenhouse gas emissions.

Bob Dudley, BP’s chief executive, writes: “The most likely path for carbon emissions, despite current government policies and intentions, does not appear sustainable.

Scale of challenge

“The projections highlight the scale of the challenge facing policy-makers at this year’s UN-led discussions in Paris. No single change or policy is likely to be sufficient on its own.

“And identifying in advance which changes are likely to be most effective is fraught with difficulty. This underpins the importance of policy-makers taking steps that lead to a global price for carbon, which provides the right incentives for everyone to play their part.”

There are already signs that senior officials involved in the UN negotiations recognise the need to dampen expectations surrounding December’s talks in Paris.

The executive secretary of the UN Framework Convention on Climate Change, Christiana Figueres, said on 3 February that changing the world’s model of economic development would “not happen overnight and it will not happen at a single conference on climate change. . . It just does not occur like that. It is a process, because of the depth of the transformation.”

If BP’s Outlook proves correct, that process may be even longer and tougher than many expect. − Climate News Network

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