Black Sea warming linked to 2012 Russian floods

Black Sea warming linked to 2012 Russian floods

Researchers say devastating 2012 Russian flood occurred only because of global warming elsewhere.

LONDON, 30 July, 2015 – Climate scientists, ever reluctant to link any one catastrophic weather event to global warming or climate change, have taken another step nearer the establishment of direct blame.

They do not say that global warming triggered a devastating flood that swept through the Russian town of Krymsk and killed more than 150 people. But they do say the flood three years ago happened only because of decades of rising temperatures nearby.

If the surface temperatures in the Black Sea had not been rising steadily for the last 30 years, researchers report, such a flood would not have been possible.

In one of the first direct connections of this kind, Edmund Meredith of the Helmholtz Centre for Ocean Research in Kiel, Germany and colleagues spell it out.

They report in Nature Geoscience that anthropogenic warming in the Black Sea region played “a crucial role” in the extreme and unprecedented flooding that made thousands homeless, turned a town into a sea of mud, and triggered a bitter political row in Russia.

The scientists call the Krymsk floods “a showcase example” of the potential consequences of human-fuelled global warming because of rising emissions of the greenhouse gas carbon dioxide in the atmosphere in the last 200 years.

Five-metre wave

The reasoning goes like this: they looked at regional rainfall levels and found – using computer simulations – that precipitation was 300% higher on average with observed Black Sea surface temperatures, compared to simulations where the warming trend over the past 30 years was removed.

That is, the simulations showed that without past surface ocean warming, what meteorologists call deep convection – the heat-driven transport of warm, moist air to the upper atmosphere, active in thunderstorms, which often results in heavy precipitation– does not develop in the region.

What happened in July 2012 was that a cyclone moved across the Black Sea and carried moist air over to the foothills of the western Caucasus, followed by a “tongue” of saturated air over Krymsk in the form of a summer thunderstorm.

Russian officials reportedly saw the calamity coming but failed to issue a warning: a five-metre wave of water swept through a town of 57,000 people, with catastrophic consequences. The official death toll reached 172.

The Kiel researchers do not see the event as a statistical freak, but as an outcome of overall warming of the Black Sea and the Mediterranean, with the knock-on effect not just of more precipitation, but greater extremes of precipitation.

Uncertain expectations

As the great American novelist Mark Twain once observed, climate is what we expect, but weather is what we get. Because extremes are rare events, meteorologists prefer to regard them as variations that in total add up to define an average.

But as temperatures rise on average, the intensity and frequency of extremes should, on statistical reasoning, also be on the rise. Scientists have thought increasingly about the possibility of links between random events and background human activity and have warned that drought-stricken California’s vulnerability to drought is likely to increase with climate change.

But it is rare for researchers to arrive at a connection as direct as the Nature Geoscience paper that spells out the process by which a global trend drives a local tragedy.

And, very cautiously, and in very general terms, the scientists warn that such things could happen again. The climate projections, they say, promise increased sea surface temperatures and more summer cyclones in the Black Sea and Mediterranean regions.

“This suggests a corresponding increased risk of intense convective precipitation events,” they conclude. “Other coastal regions with comparable geographical features may, where similar trends are projected, be similarly affected.” – 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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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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Quantum leap taken in measuring greenhouse effect

Quantum leap taken in measuring greenhouse effect

New technique for analysing satellite data will allow scientists to predict more accurately how much the Earth will warm as a result of carbon dioxide emissions.

LONDON, 8 July, 2015 – British scientists have devised a new way to observe the greenhouse world, enabling researchers to measure with exquisite accuracy how atmospheric carbon dioxide builds up, migrates, evolves and absorbs radiation.

The technique will allow more accurate predictions about how much the Earth is likely to warm over the next few decades as a result of the inexorable rise in atmospheric CO2 – from car exhausts, power station chimneys and burning forests – that drives global warming and climate change.

More than a century has elapsed since the Swedish Nobel laureate Svante Arrhenius first predicted the greenhouse effect, but scientists have until now only been able to establish the way CO2 absorbs light, with accuracies of about 5% at best.

Exploit laws

But Oleg Polyanksy and Jonathan Tennyson, professors in the Department of Physics and Astronomy at University College London, and colleagues report in the journal Physical Review Letters that they can exploit the laws of quantum mechanics to narrow the uncertainty to 0.3%.

The consequence is that a range of dedicated satellite missions – among them Japan’s Greenhouse Gas Observing Satellite (GOSAT), the US space agency NASA’s Orbiting Carbon Observatory-2 (OCO-2) and potential European Space Agency missions such as CarbonSat − will not just be able to identify industrial sources of CO2 and map their spread, but watch the gas in action, slowly warming the planet by as much as 5°C by 2100.

“It is necessary to have a very precise answer
to the question: how much radiation does
one molecule of CO2 absorb?”

“Billions of dollars are currently being spent on satellites that monitor what seems to be the inexorable growth of CO2 in our atmosphere,” Professor Tennyson says. “To interpret their results, however, it is necessary to have a very precise answer to the question: how much radiation does one molecule of CO2 absorb?

“Up until now, laboratory measurements have struggled to answer this question accurately enough to allow climate scientists to interpret their results with the detail their observations require.”

The orbiting satellite has become the climate scientist’s most prolific data delivery machine. There are satellites measuring the shrinking of the ice caps and the rate at which the ice is melting.

Besides an arsenal of weather monitors, satellites are using sophisticated sensors to monitor sea level rise, changes in ocean acidity and soil moisture, agricultural success in India, and even the energy spent in lighting up the world’s cities at night.

Warming puzzle

All these studies are part of the great global warming puzzle, but for most of the last 50 years, confirmation of what a greenhouse gas does has mainly rested on the match of CO2 levels in the atmosphere and the consequent rise in global average temperatures.

The University College team, with colleagues in Russia, the US and Poland, tried another approach. They started with the exact quantum mechanical equations obeyed by a molecule such as CO2 , then harnessed computers and subtle laboratory technologies to measure the different “colours” or wavelengths of light absorbed by molecules.

Each wavelength carries a precise energy, and highly-accurate measurements for small laboratory samples should enable researchers to scale up to equivalent accuracies for the entire atmosphere.

That means that they will be able to observe the intricacies of global warming − more or less as it happens − from high orbit, and make increasingly accurate predictions about future global warming. – Climate News Network

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Climate change may knock seafood off the menu

Climate change may knock seafood off the menu

Researchers warn of a serious threat to fish, mussels and other marine species as carbon dioxide acidifies the world’s waters and increases temperatures.

LONDON, 7 July, 2015 – Pink salmon – the smallest and most abundant of the Pacific salmon species, and a supper table mainstay in many parts of the world – may be swimming towards trouble.

And they are not the only dish likely to disappear from the menu. Mussels, oysters, clam and scallop could all become scarcer and more expensive as the seas become more acid. And as the world’s waters warm, fish will start to migrate away from their normal grounds at an ever-increasing rate.

New research shows that as the world’s waters acidify because of carbon dioxide levels in the atmosphere, the pink salmon (Oncorhynchus gorbuscha) could become smaller and less likely to survive.

Potentially problematic

Previous studies have repeatedly and consistently explored potentially problematic consequences of change in the pH value of the world’s oceans. The higher the carbon dioxide concentrations in the air as a consequence of the burning of fossil fuels, the greater the change in oceanic acidity levels.

But researchers at the University of British Columbia, Vancouver, and colleagues looked at the special problems of freshwater fish.

Only about 0.8% of the world’s water is fresh – that is, found in lakes and rivers – but freshwater species represent 40% of all fishes. Salmon spawn and the young are reared in fresh water, before taking to the seas to mature, then returning to repeat the cycle.

The Vancouver scientists report in Nature Climate Change that they tested very young embryos in water at acidity levels expected at the end of this century, and observed them for 10 weeks.

They found that these laboratory-reared salmon were smaller, and their ability to smell was reduced, which could mean problems in returning to their spawning grounds or for scenting danger and responding to it.

“It is not too late for society to benefit greatly from immediate reductions in CO2 emissions”

At the age of seaward migration, they were less able to use oxygen in their muscles, which promised problems finding food, evading predators or making long journeys.

“The increase in carbon dioxide in water is actually quite small from a chemistry perspective, so we didn’t expect to see so many effects,” said Michelle Ou, lead author of the study. “The growth, physiology and behaviour of these developing pink salmon are very much influenced by these small changes.”

Salmon aren’t the only freshwater fish at risk from climate change. Research published in the journal Environmental Toxicology and Chemistry reveals that a rise in water temperatures of 5°C could make common pesticides and industrial contaminants ever more toxic.

Ronald Patra, an environmental scientist at the Department of Planning and Environment in New South Wales, Australia, and colleagues tested rainbow trout, silver perch, rainbowfish and western carp gudgeon at temperatures higher than optimum for the species and in the presence of endosulfan, chlorpyrifos and phenol − all of which wash into waterways from the land.

Results varied according to pollutant, species and temperature, but, overall, all three chemicals became increasingly toxic as water temperatures rose.

Future toxicity

On the coast of Mangalore in southwest India, where mussel farming has become a growing industry, researchers decided to test future toxicity conditions for the green mussel.

The Society of Experimental Biology meeting in Prague learned that the bivalves were raised in high temperature and low salt conditions and exposed to toxic algae and bacteria of the kind that might be expected in a changing climate, which in turn affected the timing of the monsoon in ways that could lower seawater salinity.

“This is likely to increase the chance of outbreaks of toxic plankton blooms and make farming bivalves such as mussels increasingly challenging,” the meeting was told.

But changes to water chemistry – once again, the shift in pH values as yet more carbonic acid builds up in the seas – create problems enough for the commercial shellfisheries.

Wiley Evans, research associate at the Ocean Acidification Research Centre of the University of Alaska Fairbanks, and colleagues report in the Public Library of Science journal PLOS One that shellfish farmers off the Alaska coast might, at extra expense, have to start modifying the sea water in their hatcheries because, the researchers reported, they expect “significant effects” from acidification by 2040.

The scientists monitored for 10 months the effects of water chemistry changes on oyster, clam, scallop and other shellfish larvae.

Alaska – with a limited growing season, melting glaciers that affect salinity, and with colder waters that more readily dissolve carbon dioxide – is a special case.

But in general, as researchers have repeatedly found, increasingly corrosive waters would make it more difficult for shellfish to exploit the calcium carbonate minerals needed to make shells.

Shellfish spend their maturity in one spot, whereas fish can and do shift their grounds when the conditions become uncomfortable − with consequences for established commercial catches such as sardines and sea bass.

Likely to migrate

But a 5°C average warming in global atmospheric temperatures – and climate scientists have repeatedly warned that this is possible before 2100 – means that fish are likely to migrate away from their existing habitats considerably faster than they are doing now.

Jean-Pierre Gattuso, of the Oceanological Observatory in Villefranche, France, and colleagues looked at the evidence on a global scale and report in Science journal that, without attempts to mitigate global warming, the oceans and the creatures in them will be seriously affected by temperature changes and acidification.

This is very bad news for the millions of people in the communities that depend on the seas for a living.

“On a positive note, we still have options to substantially reduce these impacts now, but the longer we wait the fewer and fewer options we have,” warns co-author William Cheung, of the fisheries centre at Canada’s University of British Columbia.

Commenting on the research, Jason Hall-Spencer, a professor of marine biology at Plymouth University in the UK, said: “This review screams at me that the evidence is in, and it is not too late for society to benefit greatly from immediate reductions in CO2 emissions.” – Climate News Network

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Deaths mount as Pakistan heatwave is linked to climate

Deaths mount as Pakistan heatwave is linked to climate

More than 1,200 people have died as the result of an intense heatwave in southern Pakistan, and experts warn of more hot weather to come.

ISLAMABAD, 6 July, 2015 − Pakistan’s lack of preparedness in the face of increasingly intense weather events is being blamed for a growing death toll following what has been one of the most sustained heatwaves in the country since records began.

And weather experts say that the extreme heat – which lasted for much of the second half of June, and was felt most in the southern province of Sindh – is linked to climate change.

Ghulam Rasul, director general of the Pakistan Meteorological Department (PMD), told Climate News Network that the intense heat was caused by an unusually persistent area of low pressure over the Arabian Sea off Pakistan’s coast.

“Usually, in summer, cool winds blow from the sea to land, and in winter the situation is the opposite,” he said. “This moderates temperatures in the port city of Karachi, but this summer, this didn’t happen.”

Climate taskforce

Pervaiz Amir, formerly a member of a special taskforce on climate change set up by Nawaz Sharif, Pakistan’s prime minister, said: “The mortality from heatstroke could have been avoided had the Sindh provincial government responded to a heatwave forecast issued by the Pakistan Meteorological Department.”

Karachi, a city of nearly 20 million, was worst hit, with bodies piling up in the city’s morgues, and hospitals crammed with people suffering from severe heatstroke as daytime temperatures climbed to well over 40°C for extended periods.

About 65,000 heatstroke patients were treated at the city’s hospitals, and the death toll in southern Pakistan climbed above 1,200.

“This is leading to more extreme weather events, with floods and heatwaves becoming more intense and frequent in recent years”

Chronic energy shortages – a common occurrence in Pakistan – added to the problem, and the heatwave came during Ramadan, the Muslim fasting period when people do not eat or drink during daylight hours.

Experts say Karachi has also suffered from what’s known as the urban heat island effect, with poor urban planning and a lack of green spaces making conditions even hotter.

Social workers say the majority of those who have died have been the poor and homeless. At one stage, Karachi’s cemeteries ran out of space for burying the dead.

Mohsin Iqbal, a climate scientist at the state-owned Global Change Impact Study Centre in Islamabad, says temperature increases in Pakistan are above the rise in average global temperatures.

Extreme events

“This is leading to more extreme weather events, with floods and heatwaves becoming more intense and frequent in recent years,” he says.

Climate experts say weather patterns throughout the Asian sub-continent are changing, with more intense periods of heat, delays in the monsoon season and a greater incidence of drought conditions.

In April and May this year, many parts of India were hit by an intense heatwave, causing the death of more than 2,000 people.

AccuWeather, a global forecasting service, says delays in the arrival of monsoon rains and further hot periods are likely to exacerbate drought conditions in Pakistan and northwest India in July and August, threatening crop production across a wide swathe of land. – Climate News Network

  • Saleem Shaikh is a freelance climate change and science journalist, based in Islamabad, Pakistan.

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Coal investment is the most urgent climate threat

Coal investment is the most urgent climate threat

Head of the OECD says wealthy countries should help poorer nations that cannot afford to replace coal with low-carbon alternatives.

LONDON, 5 July, 2015 − The future of coal has come under scrutiny from a perhaps unlikely source – the head of the organisation representing wealthy nations that relied on coal for 32% of electricity generation last year.

Angel Gurría, secretary-general of the Organisation for Economic Co-operation and Development (OECD), said the scale of new investments in “unabated” coal-fired electricity generation − where greenhouse gases are emitted directly to the atmosphere − posed the most urgent threat to the Earth’s climate.

Speaking in London, he said governments should be sceptical about the benefits of coal for their citizens. They should rethink the role of coal in energy supply, and conduct a more rigorous evaluation of its true costs.

Environmental costs

With prices failing to fully account for the environmental, health and financial costs of coal, many of the coal plants being built today might have to be shut down before the end of their economic lifetimes.

The OECD, founded to stimulate economic progress and world trade, has 34 members drawn from the richest and most powerful industrialised countries.

But Gurría, in a passage that will hearten many developing countries in the approach to the UN climate change negotiations in Paris in November/December this year, said that if poorer nations could not afford low-carbon alternatives, then richer countries should find the money to close the cost gap.

“We have been in a process for over 20 years and, so far, the commitments simply don’t add up

Without new mitigation measures, coal generation is projected to emit more than 500 billion tonnes of CO2 between now and 2050 − eating up around half the remaining carbon budget that scientists say is consistent with keeping a global temperature rise below 2°C.

In any case, Dr Gurría said, countries’ contributions to emissions reductions after 2020 are not consistent with a 2°C pathway. He said the carbon clock was ticking and the Paris COP21 climate conference must give a clear and credible signal that governments are determined to go for a higher level of ambition.

“Calling something a process doesn’t guarantee an outcome,” he said. “We have been in a process for over 20 years and, so far, the commitments simply don’t add up.”

Continued investment in coal is one of many “misalignments” between climate goals and countries’ policies in other domains, Dr Gurría said.

Action undermined

A report by the OECD, its specialised Nuclear Energy Agency, the International Energy Agency and the International Transport Forum says policy misalignments undermine climate action in areas from tax to trade, electricity market regulation and land use.

The report says two-thirds of global energy investments still go into fossil fuels, 50% of agricultural subsidies in OECD countries harm the climate, and various tax provisions encourage fossil fuel production and use.

This “policy incoherence”, as the report describes it, limits the effectiveness of countries’ climate change efforts, and increases the cost of the transition to a low-carbon economy.

Dr Gurría urged governments to consider what needed to be done to resolve such misalignments, starting with a demand that each ministry should regularly report on which of its policies run counter to desirable climate results. − Climate News Network

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Transport sharing boosts health, wealth and climate

Transport sharing boosts health, wealth and climate

Growing public involvement in schemes to share cars and bicycles is clearly good for the environment, but it also saves money and improves people’s health.

LONDON, 4 July, 2015 − New research into how people’s habits change shows that everyone benefits from car-sharing schemes − apart from car manufacturers who suffer a loss of sales.

Car sharing is a growing social trend across Europe and North America and is expected to increase by 36% annually to 2020, especially in compact cities where people do not need a car every day but want to use one for family trips and holidays.

In the European Union, 72% of people live in cities and account for 70% of energy consumption, so car sharing could make a big contribution to reducing emissions as well as cutting air pollution. The increasing use of phone apps to locate the nearest vehicle or bicycle in a sharing scheme means organisation has become cheaper and simpler.

Sprawling cities

Even in North America, where cities are more sprawling, research shows there were 23 car-share operators in the US in 2014. They had 1.3 million members, sharing 19,115 cars.

In a survey conducted for the Transportation Sustainability Research Centre at the University of California Berkeley, investigations into the habits of 9,500 car-sharers showed that a quarter of the participants had sold their cars, and another quarter had postponed purchase of a new one.

The researchers concluded that one shared car replaced between nine and 13 privately-owned cars. For each family, this meant a 34%-41% reduction in greenhouse gas emissions.

“We’ll be living closer together in the future,
and sharing vehicles will be even more
efficient in a compact city”

Another positive finding was that car-sharers made more use of public transport, bicycles and walking. They saved money because of not having to pay out on car insurance, repairs and other costs.

Lars Böcker, a researcher in the Department of Sociology and Human Geography at Oslo University, Norway, says: “Sharing of bicycles and cars is an innovative means of transport. We’ll be living closer together in the future, and sharing vehicles will be even more efficient in a compact city.

“There are a number of advantages to joining a car-share co-operative where members share cars as needed, or a subscription scheme where you locate the closest car available when you want to go somewhere.

“Users don’t have to think about fixed expenses, parking problems, insurance, battery charging or fuelling. The idea is that you have access to a vehicle only when you need it.”

Positively inclined

Böcker has studied attitudes to the sharing of products and services in Amsterdam. He found that women were more positively inclined to sharing than men, and that older people were less willing to share services and products than younger people. People with a non-Western cultural background shared more than the average.

The survey also inquired about the motivation for sharing. In the case of car sharing and ride sharing, it was a mix of environmental considerations and the desire to save money, according to the research.

It also showed a broad swathe of the population is positively inclined to the sharing economy.

Böcker says: “This means that these schemes have a potential for considerable up-scaling; they do not represent a niche phenomenon. Only a few people need a car daily in the city, but many need access to a vehicle now and then . . .

“Sharing can give more people access to a vehicle in just this sort of situation, without there being an increase in the total amount of vehicle transport.” – Climate News Network

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Global warming threatens colder climate for Europe

Global warming threatens colder climate for Europe

New evidence that increased melting of sea ice as the Earth warms could weaken the Gulf Stream and reduce temperatures in western Europe.

LONDON, 3 July, 2015 – Scientists have yet again warned that weakening ocean circulation in the North Atlantic could deliver a climate paradox − a colder Europe as a consequence of global warming.

A study published in Nature Climate Change found that as sea ice off Iceland and Greenland retreats, the flow of cold, dense water to the bottom of the North Atlantic ocean could be reduced, and therefore weaken the warming effects of the Gulf Stream.

The great submarine current − sometimes called the Atlantic Conveyor − flows south to surface in the tropics as the Gulf Stream, which then flows north again to deliver tropic warmth to European coasts.

However, a slowdown in the natural overturning of the ocean could weaken the Gulf Stream, which in turn could cool the atmosphere over the British Isles and western Europe.

“A warm western Europe requires a cold North Atlantic, and the warming that the North Atlantic is now experiencing has the potential to result in a cooling over Western Europe,” says Kent Moore, a professor of physics at the University of Toronto Mississauga, Canada.

Calamitous change

Such a possible collapse of a natural oceanic system is predicated as one of the irreversible tipping points that could result in calamitous climate change.

Scientists have twice warned in the past six months that such change could be irreversible, unless governments jointly decide to dramatically reduce greenhouse gas emissions from the combustion of fossil fuels by switching to renewable sources of energy.

Another research group reported in March this year on how the changing salinity of the northern ocean waters − because of the increasing flow of meltwater from land-borne glaciers − threatened a weakening of the Atlantic Conveyor.

“The heat exchange is weaker – it’s like turning down the stove 20%”

In the latest study, Professor Moore and colleagues from Norway, the US and the UK looked not at changes in ocean salinity, but at the exchange of heat between sea and air.

Climate is driven by contrasts, and the flow of heat between water and wind in winter has weakened by around 20% since 1979. The Arctic is the fastest-warming region of the planet, and changes in the polar climate can have dramatic consequences for the temperate zones.

Prof Moore and his colleagues looked at wintertime data from the Iceland and Greenland Seas between 1958 and 2014, then used computer simulations to model potential changes to the Conveyor − more formally known to oceanographers and climate scientists as the Atlantic Meridional Ocean Circulation.

Cold and salty

The warm current loses its heat to the atmosphere as it moves north, and water that is both cold and salty is denser and more likely to descend.

The most effective place for such a process to happen is at the edge of the sea ice. If the sea ice retreats, then so does the region of maximum heat exchange. For the past 10,000 years or so, this heat exchange has happened at the ideal spot for surface waters to sink. Any change might not be for the better.

The Gulf Stream is the agency that makes Britain, for example, about 5°C warmer than Labrador in Canada, on the same latitude. A British government chief scientific adviser once calculated that the Gulf Stream delivered the warmth of 27,000 power stations. So if it weakens, Europe could start to feel the chill.

“The heat exchange is weaker – it’s like turning down the stove 20%,” Prof Moore says. “We believe the weakening will continue and eventually cause changes in the Atlantic Meridional Overturning Circulation and the Gulf Stream, which can impact the climate of Europe.” – Climate News Network

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Stress on water resources threatens lives and livelihoods

Stress on water resources threatens lives and livelihoods

Satellite data raises red-flag warning about the draining of underground aquifers to meet the demands of expanding populations.

LONDON, 29 June, 2015 – The planet’s great subterranean stores of water are running out – and nobody can be sure how much remains to supply billions of people in the future.

Satellite instruments used to measure the flow from 37 underground aquifers between 2003 and 2013 have revealed that at least one-third of them were seriously stressed – with little or almost no natural replenishment.

The research was conducted by scientists from California and the US space agency NASA, who report in the journal Water Resources Research that they used data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites to calculate what is happening to aquifers.

The two satellites measure variations in the gravitational pull of the planet’s surface, and have already revealed changes in the mass of ice sheets on the planetary surface. But buried water, too, has mass, and changes in the mass of bedrock in known aquifer regions would therefore offer a guide to depletion.

Driest regions

Not surprisingly, the researchers found that those regions that are already driest were drawing most heavily on the groundwater below the surface.

The Arabian aquifer system, − the principal water source for 60 million people − is the worst stressed, followed by the Indus Basin of north-west India and Pakistan, and then the Murzuk-Djado basin in northern Africa.

The scientists warn that climate change – a consequence of increasing atmospheric carbon dioxide emissions from the human combustion of fossil fuels – and population growth will make things worse.

“What happens when a highly-stressed aquifer is located in a region with socioeconomic or political tensions that can’t supplement declining water supplies fast enough?” asks Alexandra Richey, who conducted the research as a University of California Irvine doctoral student. “We’re trying to raise red flags now to pinpoint where active management today could protect future lives and livelihoods.”

“We can no longer tolerate this level of uncertainty, especially since groundwater
is disappearing so rapidly”

Her colleague, hydrologist James Famiglietti, identified his own home state of California as a cause for concern because it is in the grip of an extended drought that threatens agriculture.

“As we’re seeing in California right now, we rely much more heavily on groundwater during drought,” he says. “When examining the sustainability of a region’s water resources, we absolutely must account for that dependence.”

Groundwater accumulates slowly in the underlying bedrock over millennia. There is no problem if it is withdrawn slowly, but human population has exploded threefold in one human lifetime, and water use has risen even faster.

Supply problem

Research like this is a demonstration of ways to address a supply problem − but there is more work to be done.

In a second study in Water Resources Research, the same team examined the challenge of trying to calculate the rates at which aquifers are being emptied, and the uncertainties as to how much might remain in them.

In the Northwest Sahara, for instance, estimates of the projected “time to depletion” varied from 10 years to 21,000 years. “In a water-scarce society,” Richey says, “we can no longer tolerate this level of uncertainty, especially since groundwater is disappearing so rapidly.”

Professor Famiglietti concludes: “I believe we need to explore the world’s aquifers as if they had the same value as oil reserves. We need to drill for water in the same way that we drill for other resources.” – Climate News Network

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