‘Hidden’ warming points to more record temperatures

‘Hidden’ warming points to more record temperatures

As scientists seek to explain the apparent slowing in global warming this century, the future seems clear: without a huge cut in emissions, there’s hotter times ahead.

LONDON, 28 July, 2015 − Global warming has seemingly slowed because the top 100 metres of the Pacific Ocean has cooled −  or it could be because natural climate cycles keep the atmosphere relatively cool for three decades and then warming accelerates for the next 30 years or so.

But while climate scientists are still trying to understand precisely why the rate of global warming this century has apparently slowed, they predict that the record-breaking temperatures in 2014 will be surpassed this year.

Potential explanations for this so-called pause are like London buses: you wait for a while, and then two come along at once.

Researchers from the US report in the journal Science that the planet has absorbed more heat than it has radiated back into space, but the extra warming is trapped, for the moment, somewhere between the 100 metre and 300 metre layers of the Pacific and Indian Oceans. That is, the warming is there, but you just can’t feel it yet.

Robust evidence

“In the long term, there is robust evidence of unabated global warming,” says Veronica Nieves, a research physicist at the NASA Jet Propulsion Laboratory in California.

Meanwhile, an essay in The Geoscientist argues that natural decadal climate cycles and the continuous rise in greenhouse gases from human combustion of fossil fuels are interacting in ways that mean that the rate of change is not a smooth upward curve, but a series of steps − some steep, some flat.

Average global temperatures have risen 0.9°C since the start of the 20th century. But research scientist Andy Chadwick, of the British Geological Survey, writes: “Anthropogenic emissions are not the only game in town, and that is why the observed temperature variation is more complex.”

Neither argument excludes the other. Both could be true, and each could be only part of the explanation. So could some of the other published analyses.

Scientists have recently argued that the missing heat may be deep in the Atlantic, or driven to depths by the Pacific trade winds,  or affected by natural cycles in both oceans.

“It is clear that, in coming decades, temperatures will continue to rise − albeit not at a uniform rate”

One group has reasoned that a recent burst of low-level volcanic activity could be screening the sunlight and lowering temperatures, while others say they never expected global warming to be consistent.

Yet others have proposed that warming continues and that the anomalies may lie in the way the data has been collected, or that even if the average temperature rises seem to have slowed, the increase in extremes of heat around the world suggests otherwise.

Computer simulation

But much of such argument has been supported by computer simulation and “what-if” logic.

Dr Nieves and her colleagues looked at direct ocean temperature measurements collected over the last 20 years − some of them from a network of 3,500 floats known as the Argo array − to build up a picture of heat driven below the ocean surface, piling up in the Western Pacific, and even “leaking” into the Indian Ocean.

This is while the water surfaces remained unexpectedly cool, during a 30-year phase known to oceanographers and climate scientists as the Pacific Decadal Oscillation.

Dr Chadwick went back to records dating from the close of the 19th century to show a clear warming of more than 100 years, but divided into 30-year “ramps” when temperatures rose steeply, and “steps” when temperatures were roughly constant or fell very slightly, in ways consistent with natural oscillations in ocean and atmosphere.

Temperatures fell between 1880 and 1910, and between 1945 and 1975, and had “flattened off” in the 21st century. The long-term trend correlated closely with the rise in carbon dioxide levels in the atmosphere. And simulations of the future suggested more rapid warming to come.

“It is clear that, in coming decades, temperatures will continue to rise,” Dr Chadwick predicts, “albeit not at a uniform rate.” – Climate News Network

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Mangroves hold key to Indonesia’s emissions cuts

Mangroves hold key to Indonesia’s emissions cuts

New study says Indonesia could go a quarter of the way to reaching its 2020 target for carbon emissions reduction by ending the destruction of its vital mangrove forests.

LONDON, 27 July, 2015 – Indonesia, one of the world’s largest carbon emitters, would take a major step towards losing that tag by protecting its massive mangrove forests, according to new research.

The mangroves, which store prodigious quantities of carbon, are currently disappearing fast − often destroyed to make room for aquaculture to satisfy the wants of lucrative foreign markets.

But a team from the Centre for International Forestry Research (CIFOR) and colleagues report in the journal Nature Climate Change that protecting the mangroves could take Indonesia a quarter of the way to achieving the whole of the greenhouse gas emissions cuts it plans for 2020.

Indonesia, with the longest coastline in the tropics, has more mangroves than any other country − more than 2.9 million hectares. But it also has one of the world’s fastest rates of mangrove loss.

The main threats to the forests include conversion to shrimp ponds, logging, conversion of land to agriculture or salt pans, and degradation by oil spills and pollution.

In 2013, Indonesia’s revenue from shrimp exports was close to US$1.5bn, almost 40% of the total revenue from the country’s fishery sector.

Grave threat

The researchers say the Indonesian mangroves, some of which grow to 50 metres in height, store 3.14 billion tonnes of carbon, which amounts to one-third of the carbon stored in Earth’s coastal ecosystems.

But they are under grave threat. In the last 30 years, 40% of these coastal forests have gone, and the annual rate of loss now is about 52,000 hectares, causing substantial greenhouse gas emissions.

The current rate of destruction means that 190 million tonnes of CO2-equivalent (CO2e) are emitted annually. That is 42% of the world’s annual emissions from the destruction of coastal ecosystem services − marshes, mangroves and sea grasses.

Put more graphically, Indonesia’s destruction of its mangroves emits as much greenhouse gas as if every car in the country was driven around the world twice.

“We hope that these numbers help policymakers see mangroves as a huge opportunity for climate change mitigation,” says Daniel Murdiyarso, principal scientist at CIFOR and lead author of the paper.

“It is time to acknowledge that mangroves must be part of the solution to climate change”

“But to make progress, it is crucial that mangroves are protected and managed sustainably. It is time to acknowledge that mangroves must be part of the solution to climate change.”

Dr Murdiyarso is also co-author of a CIFOR guide on climate change adaptation and mitigation in Indonesia’s wetlands.

In a separate study, published in the Royal Society Proceedings A, further light is shed on the crucial role mangroves play in protecting coastal areas from sea level rise caused by climate change.

The study, by researchers at the University of Southampton, UK, and colleagues from the universities of Auckland and Waikato in New Zealand, used mathematical simulations to discover how mangrove forests respond to elevated sea levels.

Mesh-like roots

When sea levels rise, they found, areas in estuaries and river deltas without mangroves are likely to widen from erosion, and more water will encroach inwards. But mangrove regions prevent this effect, probably because of soil building up around the trees’ mesh-like roots and acting to reduce energy from waves and tidal currents.

Dr Barend van Maanen, a coastal systems researcher in the department of engineering and environment at the University of Southampton, explains: “As a mangrove forest begins to develop, the creation of a network of channels is relatively fast. Tidal currents, sediment transport and mangroves significantly modify the estuarine environment, creating a dense channel network.

“Within the mangrove forest, these channels become shallower through organic matter from the trees . . . and sediment trapping (caused by the mangroves), and the sea bed begins to rise, with bed elevation increasing a few millimetres per year until the area is no longer inundated by the tide.”

In modelling of sea level rise in the study, the ability of mangrove forest to gradually create a buffer between sea and land occurs even when the area is subjected to potential sea level rises of up to 0.5mm per year.

“These findings show that mangrove forests play a central role in estuarine and salt marsh environments,” says Giovanni Coco, associate professor in the school of environment at the University of Auckland.

“As we anticipate changes caused by climate change, it’s important to know the effect sea level rise might have, particularly around our coasts.” − Climate News Network

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Norway pumps up ‘green battery’ plan for Europe

Norway pumps up ‘green battery’ plan for Europe

Hydraulic engineers in Norway aim to use surplus power from wind and sun to cut the need for fossil fuel plants to boost European electricity supplies.

LONDON, 26 July, 2015 − Norway is hoping to become the “green battery of Europe” by using its hydropower plants to provide instant extra electricity if production from wind and solar power sources in other countries fade.

Without building any new power stations, engineers believe they could use the existing network to instantly boost European supplies and avoid other countries having to switch on fossil fuel plants to make up shortfalls.

Norway has 937 hydropower plants, which provide 96% of its electricity, making it the sixth largest hydropower producer in the world − despite having a population of only five million.

Europe already has 400 million people in 24 countries connected to a single grid, with power surpluses from one country being exported to neighbours or imported as national needs change.

Supply and demand

As more and more renewables are installed across the continent, the problem of balancing supply and demand gets more difficult.

Because supply from wind and sun sources fluctuates, the grid needs back-up plants to keep the power constant. At present, this means that many countries have to keep gas and coal plants on standby to make up any shortage.

However, the Hydraulic Laboratory at the Norwegian University of Science and Technology (NTNU) in Trondheim believes it can engineer the country’s vast power plants so that they can themselves be a giant standby battery that can be turned on and off.

When there is surplus wind or solar power in Europe, the electricity it generates can be imported to pump water uphill to keep re-filling the Norwegian reservoirs. This is, in effect, electricity that is stored, because when energy is needed again the generators can be turned back on to produce hydropower.

“Norwegian mountains are full of water tunnels. It’s like an anthill.”

The problem at the moment is that even hydropower is not instant. This is because water takes time to flow through the vast network of pipes and the turbines to reach the correct speed to provide stable power to the grid at the correct frequency of alternating current.

Norway currently has more kilometres of pipes carrying water to its hydroelectricity plants than it has miles of road, so controlling the flow is the key.

But Kaspar Vereide, a doctoral student in the department of hydraulic and environmental engineering at NTNU, has designed a model solution, with funding from the Centre for Environmental Design of Renewable Energy.

By creating a sealed surge chamber in rock close to the turbines, engineers can feed electricity, at the right frequency, into the grid immediately. The empty chamber contains air that is compressed as the space is filled with water. So, when the valves are open, the water can instantly turn turbines at the correct speed.

Vereide says: “Norwegian mountains are full of water tunnels. It’s like an anthill.”

The length of the waterway, he says, can be many kilometres, though this will require the engineers to accelerate the water to reach the turbines.

His solution involves blowing out a cavern inside the water tunnel near the turbine where the electricity is to be generated, creating a surge chamber where water at the correct velocity can reach the turbines immediately.

Fluctuations in power

He admits that his design is still at the early stages of development. The surge chambers have to be designed to avoid fluctuations in power needs, which can cause uncontrolled blowouts of air into the power plants, risking damage.

“We have to be able to control these load fluctuations that occur,” he says. “Among other things, it’s important to determine how big surge chambers need to be to function best. My task is to figure out the optimal design for the chambers.”

Vereide says that plants have traditionally been run very smoothly and quietly, with few stops and starts to create these fluctuations. But to become the green battery of Europe, the power plants would need to be started and stopped much more often − and then the problem of load fluctuations would increase significantly.

“We’ll benefit a lot from developing these new technologies, both in order to keep electrical frequency stable and to run power plants more aggressively to serve a large market,” he says. – Climate News Network

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Economic changes needed to tackle climate challenges

Economic changes needed to tackle climate challenges

A meeting building towards the Paris climate summit hears Ireland’s president call for a new economic order to address the threats of global warming.

LONDON, 25 July, 2015 − The president of Ireland, Michael D Higgins, says the world needs a whole new economic framework to tackle the consequences of the warming caused by emissions of greenhouse gases.

Speaking at a meeting in Paris, entitled the Summit of Consciences for the Climate, he said this generation could be the last with the chance of responding to the urgent, uncontested effects of climate change.

The challenge of climate change, he said, provided opportunities to construct a new order for humanity and for the planet.

“Climate change is grounded in forms of development and industrialisation that are based on the exploitation of fossil fuels, with an assumption of infinite growth,”  he  told the meeting.

Climate agreement

The Paris summit, attended by religious groups, Nobel  laureates and artists, as well as prominent politicians, was convened by the President of France, François Hollande, and is one of a series of gatherings to be held in the run-up to the UN climate change conference in Paris in December, at which a new global climate agreement is due to be finalised.

Kofi Annan, the former UN secretary-general, and Mary Robinson, the UN’s special envoy on climate change, were among those speaking at the meeting.

In an interview with the Irish Times, Higgins said that the neo-liberal model of economic development prevalent in western countries advocated the rolling-back of the state.

“The World Bank says we will have to go from billions to trillions to pay for the agendas that will flow from the conferences in 2015”

Massive movements of capital had created what he termed great fissures of inequality, and such freewheeling capitalism had shown itself capable of dislodging the whole fiscal system.

The global challenges of climate change and inequality could not be met if governments were not in control of their economies, Higgins said.

Besides the year-end Paris summit, several other significant  conferences are being held this year, including a UN meeting focusing on a follow-up to the Millennium Development Goals.

“The World Bank says we will have to go from billions to trillions to pay for the agendas that will flow from the conferences in 2015,” Higgins said. “The issue is, can you do this with a minimised state?”

Global diversities

François Hollande told the meeting that it was up to every individual to see what he or she could do to save the planet. “There are philosophies, there are convictions, there are global diversities that should at a certain point unite – and unite to make decisions,” he said.

Mary Robinson, a former president of Ireland, said that leaders of developing countries are trying to find a way of building a more sustainable model of development without increasing emissions of climate-changing greenhouse gases.

Kofi Annan said the threat posed by climate change is as great as the danger of nuclear war, and he quoted the former Soviet leader, Nikita Khrushchev, who said that, in the event of a nuclear conflagration, “the living will envy the dead”. – Climate News Network

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Emissions threaten age of uncertainty for carbon dating

Emissions threaten age of uncertainty for carbon dating

New study warns that rising CO2 levels from the burning of fossil fuels will undermine the precision with which once-living things can now be scientifically dated.

LONDON, 24 July, 2015 – Climate change driven by increasing levels of atmospheric carbon dioxide will not just damage the health of the planet. A UK scientist now warns that it will also make life increasingly difficult for archaeologists, forensic scientists, art experts, fraud and forgery detectives, and people who detect ivory poachers.

That is because the swelling volume of carbon pumped into the atmosphere from factory and power station chimneys and motor and airline exhausts is beginning to artificially “age” the planet’s atmosphere and bedevil attempts to use the technology known as carbon dating.

If emissions continue under the now-notorious “business as usual” scenario, then by 2050 a brand-new cotton shirt will have the same radiocarbon-dating age as the cloak worn by William the Conqueror when he invaded Britain in 1066.

But if, on the other hand, the world’s governments do move swiftly to curb fossil fuel emissions, then by 2050 a brand-new cotton shirt will seem only 100 years old.

Forensic scientists exhuming a skeleton, Egyptologists investigating an ancient tomb, and fraud detectives concerned with suspected forgeries of Renaissance paintings could still possibly make allowances for that.

Natural ratio

Radiocarbon dating is a 70-year-old technique now used with increasing precision to date anything once alive from the last 50,000 years. It exploits the natural ratio of two isotopes of carbon in the atmosphere.

Plants, and the animals that eat them, absorb radioactive carbon-14 and stable carbon-12 from the atmosphere in proportions which – except during the atmospheric nuclear weapons tests in the 1950s and 1960s − have not changed much from the Ice Ages to the beginning of the Industrial Revolution.

When the tree dies or the animal becomes old bones, the carbon-14 decays at a predictable rate, and the ratio that remains in the laboratory sample is a measure of the specimen’s age.

But Heather Graven, a lecturer in climate physics and Earth observation at Imperial College London, reports in the US journal Proceedings of the National Academy of Sciences that by 2020, as the fossil fuel emissions mount up, the fraction of carbon-14 in the atmosphere could drop to such a level that carbon-dating could become increasingly uncertain.

“Given current emissions trends . . . ‘ageing’ of the atmosphere is likely to occur much faster and with a larger magnitude than previously expected”

Fossil fuels are reservoirs of carbon from plants and algae that died so long ago that all the carbon-14 has decayed. When carbon dioxide exhausts from combustion engines reach the atmosphere, they increase the levels of non-radioactive carbon, artificially ageing the atmosphere and, accordingly the new growths that exploit the atmospheric carbon.

Dr Graven warns that now, from the point of view of an archaeologist using radiocarbon dating, the planet’s atmosphere is ageing at the rate of 30 or so years for every year of international inaction.

If there are no steps to reduce emissions, then by 2050 the atmosphere will have a signature of what carbon ratios were 1,000 years ago. By 2100, just one human lifetime away, the atmospheric clock will have been turned back to the era of Imperial Rome.

That means that a freshly-dead dung beetle that falls into an Egyptian tomb dating from the reign of Cleopatra would have the same radiocarbon age as the scarab that was trapped in the tomb under the sarcophagus 20 centuries ago.

“Given current emissions trends, fossil fuel emission-driven artificial ‘ageing’ of the atmosphere is likely to occur much faster and with a larger magnitude than previously expected,” Dr Graven concludes.

“This finding has strong and, as yet, unrecognised implications for many applications of radiocarbon in various fields, and it implies that radiocarbon dating may no longer provide definitive ages for samples up to 2,000 years old.”

Historic sources

It also could, for instance, mean that border officials may not be able to distinguish museum collection ivory from illegally-poached elephant tusks, that fraud officers will not be able to confirm the age of costly single malt whisky or vintage claret, and that Jewish and Christian scholars may no longer be able to date important historic sources such as the Dead Sea Scrolls, or resolve doubts about the much-contested provenance of iconic relics such as the Shroud of Turin.

Dr Graven, who uses radiocarbon technology to study the global carbon cycle, told Climate News Network: “I was inspired by how many innovative applications there are for radiocarbon in diverse fields. This made me realise that fossil fuel emissions are likely to have an impact on these various uses for radiocarbon.

“By quantifying the potential changes over this century with model simulations, this study could help other scientists who use radiocarbon to prepare for forthcoming changes.” – Climate News Network

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UK’s leading scientists urge immediate climate action

UK scientists urge immediate climate action

The pre-eminent institutions in British science and engineering – some with long records of promoting fossil fuels – say the UK should lead the way to a zero carbon world. 

LONDON, 23 July, 2015 – Twenty-four of Britain’s most learned scientific societies have joined forces to urge the British government to act now to curb greenhouse gas emissions.

They want the UK to take the lead in intergovernmental talks in Paris in December, and keep global warming to an average of 2°C this century.

The societies want drastic reductions in the burning of fossil fuels, a shift towards energy efficiency and renewable sources of energy, and other changes to sidestep damaging climate change as a consequence of the atmospheric build-up of carbon dioxide.

A joint communiqué agreed by organisations that speak for the most advanced research in the humanities, the social sciences, the arts, science, medicine and engineering urges action by governments, individuals, business, local communities and public institutions, to make the transition to a zero carbon world.

That any of the institutions has signed the communiqué is no surprise: many of them have delivered such advice separately, and some of them many times. What is significant about this latest statement is that all sorts of scholarly authorities with quite different origins have been united in one unequivocal statement.

Hydrocarbon pioneers

The Geological Society of London, for instance, the oldest such in the world, is backed by the fossil fuel industry and has sponsored petroleum, gas and coal prospecting and exploitation for much of its 200-year history.

The Royal Society of Chemistry was an intellectual centre for scientists and industrialists who pioneered the use of hydrocarbons derived from stores of crude oil and seams of coal.

The Royal Society provided intellectual support for the scientists who made the Industrial Revolution possible – and then endorsed the conclusions by a new generation that first identified the dangers inherent in atmospheric pollution, and then began systematically measuring the cost to the planet’s environment of such advances.

The signatories also include the Institutions of Civil Engineers and Chemical Engineers, members of which played a powerful role in the spread and advance of a fossil-fuel burning economy, as well as the Zoological Society of London, which has been more concerned with protecting the wildlife at risk from human activity, and the Royal Meteorological Society,  whose members have identified, measured and projected all the evidence of climate change.

“At or above 4°C, the risks include…fundamental changes to human activities that today are taken for granted”

Calling on the British government to show leadership on climate action, when the world’s nations meet in Paris in December to try once more to reach an enforceable agreement on cuts in greenhouse gas emissions, Lord Stern, the President of the British Academy, said: “The UK led the world with both the modern scientific revolution and the industrial revolution, and must again lead now on the creation of a safer, cleaner and more prosperous world.

“Tackling climate change is a responsibility for the whole world, but the UK has a special position at the forefront of international efforts.”

The communiqué points out that while climate change poses far-reaching threats, the ways in which humankind tackles the issue present great opportunity, with vast potential for innovation in low-carbon technologies.

But not to take action could be catastrophic. “At or above 4°C, the risks include species extinction, global and regional food insecurity, and fundamental changes to human activities that today are taken for granted,” the communiqué says. – Climate News Network

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Global warming’s record-breaking trend continues

Global warming’s record-breaking trend continues

Detailed update by hundreds of scientists on climate indicators in 2014 reveals highest recorded rises in temperatures, sea levels and greenhouse gases.

LONDON, 22 July, 2015 – Forget talk of a slowdown in global warming. Scientists say the climate is heading smartly in the opposite direction, with 2014 proving to be a record-breaking year.

The US National Oceanic and Atmospheric Administration (NOAA), one of the most respected sources of climate science, says that last year “the most essential indicators of Earth’s changing climate continued to reflect trends of a warming planet”. Some − including rising land and ocean temperatures, sea levels and greenhouse gases − reached record highs.

The authoritative report by the NOAA’s Centre for Weather and Climate at the National Centres for Environmental Information (NCEI), published by the American Meterological Society, draws on contributions from 413 scientists in 58 countries to provide a detailed update on global climate indicators.

“The variety of indicators shows us how our climate is changing, not just in temperature but from the depths of the oceans to the outer atmosphere,” says Thomas R. Karl, director of the NCEI.

Rising concentrations

The authors report that concentrations of greenhouse gases continued to climb during the year. Atmospheric carbon dioxide concentrations rose by 1.9 parts per million (ppm), reaching a global average of 397.2 ppm for the year. This compares with a global average of 354ppm in 1990 when the first edition of this report was published. And levels of methane and nitrous oxide also went up.

“Variety of indicators shows how our climate is changing, not just in temperature but from the depths of the oceans to the outer atmosphere”

Four independent global datasets showed that 2014 was the warmest year on record, with the warmth widespread across land areas.

Europe experienced its warmest year; Africa had above-average temperatures across most of the continent throughout 2014; Australia recorded its third warmest year; and Mexico had its warmest. Eastern North America was the only major region to experience below-average annual temperatures.

Global average sea level rose to a record high, and the globally averaged sea surface temperature was also the highest recorded. The warmth was particularly notable in the North Pacific Ocean, where temperatures are in part probably driven by a transition of the Pacific decadal oscillation – a recurring pattern of ocean-atmosphere climate variability centred in the region.

Earlier snow melt

The Arctic continued to warm, and sea ice extent remained low. Arctic snow melt occurred 20–30 days earlier than the 1998–2010 average. On the North Slope of Alaska, record high temperatures at a 20-metre depth were measured at four of five permafrost observatories. The eight lowest minimum sea ice extents during this period have occurred in the last eight years.

But temperature patterns across the Antarctic showed strong seasonal and regional patterns of warmer-than-normal and cooler-than-normal conditions, resulting in near-average conditions for the year for the continent as a whole. Last year was the third consecutive year of record maximum sea ice extent in the Antarctic.

The El Niño-Southern Oscillation (ENSO), a periodic warming of the water in the central and eastern Pacific that disrupts weather over thousands of miles, was in a neutral state during 2014, although it was on the cool side of neutral at the beginning of the year and approached warm El Niño conditions by the end of the year. This pattern played a major role in several regional climate outcomes.

There were 91 tropical cyclones in 2014, well above the 1981-2010 average of 82 storms. But the North Atlantic season, as in 2013, was quieter than most years of the last two decades with respect to the number of storms. – Climate News Network

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Recession cut US emissions, not falling coal use

Recession cut US emissions, not falling coal use

Researchers say it was the economy rather than the replacement of coal by natural gas that drove the recent drop in US emissions of the main greenhouse gas.

LONDON, 21 July, 2015 – Between 2007 and 2013 emissions of carbon dioxide from fossil fuels burnt in the US fell significantly − by about 11% − and many analysts credited this to a change from coal to natural gas in electricity production.

But new research says it was, in fact, the economic recession that explains most of the decline, and more extensive use of natural gas may not do much to slow global warming.

“Natural gas emits half as much CO2 as coal when used to make electricity,” says research professor Laixiang Sun, of the Austria-based International Institute for Applied Systems Analysis (IIASA), who conducted the study with colleagues from the University of Maryland, US.

Release of methane

But that is only part of the story, he says in a paper published in the journal Nature Communications. “This calculation fails to take into account the release of methane from natural gas wells and pipelines, which also contributes to climate change.”

Methane is 34 times more potent a greenhouse gas than CO2 over a century, but 84 times more over just 20 years.

In the US, coal-powered electricity fell from 50% to 37% of the generation mix between 2007 and 2012, with most of it replaced by natural gas − in large part, due to fracking and underground mapping technologies.

If we don’t understand the factors that led to this emissions reduction, we won’t know how to effectively reduce emissions in the future”

The researchers say that because this shift occurred at the same time as the reduction in emissions, many commentators linked the two, mistaking temporal co-incidence for causality.

Apart from the state of the economy, they say, there were several other factors involved: population growth, for example, and energy efficiency, which both also affect total emissions.

“If we don’t understand the factors that led to this emissions reduction, we won’t know how to effectively reduce emissions in the future,” says Klaus Hubacek, an ecological economist at the University of Maryland.

So the researchers used a method known as structural decomposition analysis to tease apart the various contributions of different factors related to energy use and CO2 emissions.

This enabled them to determine the relative influence of changes in population, amount and patterns of consumption, production structure, and changes in fuel mix on total emissions of greenhouse gases.

They found that from 1997 to 2007, a period of rising emissions, 71% of the increase was due to increasing US consumption of goods and services, with the remainder due to population growth.

Mix of factors

But from 2007 to 2009, when emissions declined the most, the study finds that 83% of the decrease was due to economic factors, including consumption and production changes, and just 17% of the decline related to changes in the fuel mix. After 2009, emissions declined by only about 1%, and this was due to a mix of all three factors.

Knowing the relative influence of such factors on emissions is important for devising effective policies for future climate mitigation, the researchers say.

In particular, they say their findings may indicate that further increases in the use of natural gas may not have major benefits for the climate.

Natural gas can replace coal, but research also shows that, if it is cheap and abundant, it can limit the growth of carbon-neutral renewable energy sources.

Prof Sun says: “Sustaining economic growth while also drastically reducing emissions to the levels targeted by the Obama Administration will depend upon large additional decreases in the energy intensity of the US economy, as well as radical decarbonisation of the energy sector.” – Climate News Network

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Melting sea ice means shortage of bear necessities

Melting sea ice means shortage of bear necessities

Researchers explode theory that polar bears can use hibernation techniques to last without food as climate change reduces their summertime hunting habitat.

LONDON, 20 July, 2015 – Global warming is likely to leave the polar bear high and dry and very hungry as increasing loss of sea ice reduces the hunting grounds of the Arctic’s top predator.

Researchers have established that while Ursus maritimus can survive for months without eating during winter hibernation, in the summertime it is not much better at going without food than any other mammal.

The polar bear is capable of shutting its own metabolism down to astonishingly low levels during hibernation and, until now, zoologists have surmised that the bear could minimise energy losses by entering a hibernation-like state when deprived of food.

But John Whiteman, a doctoral student in ecology, zoology and physiology at the University of Wyoming, and colleagues report in Science journal that that theory is wrong. Once they are up and hunting, bears need food.

Energy expenditure

“We report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, non-hibernating mammals,” they write.

As carbon dioxide levels in the atmosphere creep up, as a consequence of the human combustion of fossil fuels, so Arctic temperatures have on average risen.

The loss of sea ice in the Arctic has, over the last decade, happened even faster than climate scientists predicted, which creates problems for bears that need to hunt and gorge on high-calorie diets in preparation for the winter.

The polar bear hunts on the ice, and its preferred diet is the blubber-rich flesh of seals and small whales. On shore, it must forage for scraps, berries and small mammals while waiting for the seas to freeze again.

“Polar bears appear unable to meaningfully prolong their reliance on stored energy”

But Arctic summers have stayed milder for longer, and the areas of summer sea ice have steadily dwindled. So the bears have spent increasing periods without their preferred diet.

The orthodoxy had been that bears, while waiting for the first freeze, had been able to enter a state called “walking hibernation”. Whiteman and his fellow researchers took a closer look.

With help from government agencies, a US coastguard icebreaker, helicopter pilots and a large number of other people, they captured two dozen polar bears, fitted satellite collars, and implanted little devices that recorded body temperature and tracked their movements on shore and on ice in the Beaufort Sea, north of Alaska and Canada, between 2008 and 2010.

Core temperature

They found that the bears could do something physiologically clever to keep warm while swimming – they could temporarily cool their outermost skin layers to insulate their inner selves and keep their core body temperatures at a healthy level, and one bear was reported to have survived a nine-day swim from shore to ice.

But they also found that the bears were not much better than other mammals at walking around on dry land, looking for food that wasn’t there.

“We found that polar bears appear unable to meaningfully prolong their reliance on stored energy, confirming their vulnerability to lost hunting opportunities on the sea ice − even as they surprised us by also exhibiting an unusual ability to minimise heat loss while swimming in Arctic waters,” Whiteman says.

The evidence, however, suggested that “walking hibernation” didn’t actually exist. The researchers conclude that the bears “are unlikely to avoid deleterious loss in body condition, and ultimately survival, that are expected with continuous ice loss and lengthening of the ice-melt period”. – Climate News Network

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People and planet benefit from ‘green’ buildings

People and planet benefit from ‘green’ buildings

Research worldwide shows that environmentally-friendly buildings are much better for the health of the people who live and work in them, as well as for the Earth.

LONDON, 19 July, 2015 – Buildings that are designed to cut water and energy use and make as little impact on the surrounding environment as possible make life much better for their occupants too.

Studies into 69,000 buildings − homes, offices and factories − in 150 countries show that there are fewer illnesses among residents and workers, who report they are more comfortable and happier. Employers also find they are more productive.

Companies that opt for “green” buildings gain because workers stay longer in their jobs and have fewer absences, while recruitment is easier because new employees are attracted to environmentally-friendly buildings.

Dr. Joseph Allen and fellow environmental health researchers at the Harvard TH Chan School of Public Health in the US studied reports from across the world into the effect of green buildings on the health of the occupants. Fifteen studies are incorporated into the review, published in the journal Current Environmental Health Reports.

Healthier effects

There are now 3.5 billion square feet (0.325 sq metres) of certified green building space available worldwide, and researchers in many different countries have been measuring the effects to see if these buildings are also “ healthier” buildings.

“Overall, the initial scientific evidence indicates better indoor environmental quality in green buildings versus non-green buildings, with direct benefits to human health for occupants of those buildings,” Allen says.

Occupants of green buildings are in general more satisfied with the indoor air quality, their workspace, building cleanliness, and maintenance in general, he adds.

The information is important for future building design because modern humans
spend 90% of their time indoors.

The research measured internal air quality, light, noise and the presence of chemicals that might adversely affect health, as well as asking the people who live and work in them about their experience.

The information is important for future building design because, as the researchers point out, modern humans spend 90% of their time indoors.

To gauge the effect on health and well-being, the scientists looked at many studies that had taken into account factors that influence health − including radiological, chemical, biological and physical aspects of indoor environmental hazards.

Air quality

They looked at air quality, ventilation, filtration, lighting and acoustics, and studied the architecture, the quality of the canteens, access to natural light, and the building’s surroundings.

In residential buildings, there were fewer asthma and other respiratory illnesses among children, and across all green buildings there fewer cases of sick building syndrome symptoms, with better physical and mental health all round.

The one area that did not score better was acoustics, with several studies reporting lower satisfaction about noise levels.

Where hospitals had been constructed as green buildings, the researchers found a better quality of care for patients. In one study, there were 70% fewer blood stream infections, improved record keeping, and overall patient mortality fell by 11% − although the scientists were unable to pinpoint what factors produced such a startling improvement. – Climate News Network

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