Climate change and the role of clouds

BY GRAHAM READFEARN

ABC Environment, 12 JULY 2010

Clouds and water vapour play an important part in climate change, but the exact details of their role remains cloudy.

PHILOSOPHERS, artists, politicians and daydreaming kids have long looked to the sky's ungraspable clouds in search of meaning. But those innocuous clumps of water and ice, seen by British poet William Wordsworth as lonely wanderers, are being closely watched by climate scientists for clues to our future.

"It still remains one of the top challenges in climate research - getting a better understanding of clouds,'' says Steve Sherwood, a professor of atmospheric physics at the University of New South Wales Climate Research Centre. "It's the main known unknown in predicting future climate.''

For the average observer gazing wistfully into the troposphere where the vast majority of clouds reside, clouds can be a confusing and complex phenomenon to understand. With the climate too, clouds have a complicated relationship because they both cool and warm the planet, acting like a shade in reflecting the sun's radiation back into space but also stopping heat escaping from the ground.

Water vapour in the atmosphere is invisible and everywhere - it is our most abundant greenhouse gas. The way that water vapour affects the climate is similar to that of carbon dioxide, methane and other gases. They all absorb and re-emit radiation, acting like a blanket enfolding the globe.

"We have quite a good understanding of water vapour,'' says Sherwood. "All our models say water vapour will increase by about seven per cent for every one degree of warming and we have observations to show that's happening."

It is only when the water vapour condenses into a cloud that it can be seen. When we can see it, its bright whiteness also reflects sunlight back into space.

"The problem that we have is predicting how much of that vapour will condense to clouds and how much light they reflect. That is very challenging," explains Sherwood.

"If we had a planet with no clouds then the surface temperature would not be all that different - a little cooler maybe but only by a few degrees. But if you took out the water vapour then it would be significantly cooler - about 15ºC."

What goes up

The race is on to get a better understanding of how clouds will change as the globe continues on a warming track which has seen each decade since the 1940s getting progressively warmer.

While it might seem like common sense that a warmer world means more evaporation and, in turn, means more clouds, it is a common misunderstanding.

A warmer planet will likely speed up the hydrological cycle - the process of evaporation and rainfall - but it won't necessarily give any more or less clouds in the sky.

"All evaporation is eventually matched by rainfall - everything that goes up, must come down,'' says Dr Rob Colman, an expert on climate feedbacks at the Centre for Australian Weather and Climate Research.

"What stays up there as water vapour depends on temperature. If you warm the air by one degree then it can hold more water.

"As greenhouse gases increase, the air is warmer and holds more water vapour and then further reinforces that warming."

Colman says that it is primarily the fault of clouds that predictions of future temperature rises are given with margins of error.

"Very small changes in the way that clouds behave can have a very big impact,'' he says. "One major source of uncertainty of whether we will have warming of 2ºC or 4ºC by the end of the century comes from uncertainty over how clouds will respond."

The future is cloudy

Research published in the journal Science last year looked at the northeast Pacific region and found that low-level clouds seem to thin-out as the oceans get warmer.

A gradual reduction in this cloud cover could already be kick-starting a complex feedback cycle.

Fewer low-level clouds would lead to more sunlight hitting the oceans, causing further warming and further reducing cloud cover.

One US$30 million three-year project, the VAMOS Ocean Cloud Atmosphere Land Study which concludes this year, has seen more than 200 scientists from 10 countries studying the complex feedbacks between clouds, oceans and the land. In particular the team is focussing on the vast decks of clouds, greater in size than the USA, which hover over the Pacific.

These clouds are seen as playing a significant role in the globe's energy balance so understanding their reaction to increased temperatures coming from rising greenhouse gas emissions will be crucial.

Giving clouds a spray

As well as the generation of greenhouse gases there are other emissions which are taking scientists' interest.

Clouds also need aerosols - tiny particles from both natural and human activities - to be able to form. One research project being part-funded by billionaire Bill Gates is trying to find out if spraying sea water containing salt into the atmosphere could generate whiter clouds in the future.

In 2007, an 11-strong team of researchers including five from Australia used computer models to suggest that an increase in clouds and rainfall observed over parts of Australia since the 1950s was, in part, down to pollution drifting across from Asia. When the researchers removed these human-caused aerosols from their calculations, the models failed to recreate the trends.

But being able to set a benchmark to gauge those long-term changes is tricky. Meteorologists have been keeping daily records of rainfall and temperature since the mid 1800s. Cloud observations have been carried out by people on land and sea but the records don't stretch back as far.

Australia's own Bureau of Meteorology is currently compiling records of observations made at 165 surface stations from 1957 onwards.

Colman says preliminary analysis showed they were consistent with more recent satellite observations which, until recently, have only been able to give a flat picture of cloud. When viewed from space, clouds sitting beneath other clouds are obscured. But researchers like Sherwood and Colman have a new weapon, with data from a sophisticated new group of satellites now becoming available.

"For the first time we are now getting hold of very accurate three-dimensional data,'' says Colman. "It's a very exciting time for cloud science."

Rising CO2 may lead Nemo to danger

By Katherine Nightingale for ABC Science Online

Updated Wed Jul 7, 2010 

Global warming could have an unexpected effect on the clownfish star of Finding Nemo and his kind, by making them indulge in risky behaviour, say researchers.

Previous research indicates that as carbon dioxide (CO2) levels in the atmosphere climb the surface water of the oceans could become more acidic.

Scientists have already shown that this acidification interferes with fish larvae's sense of smell and ability to find a suitable home.

Now research led by marine researcher Professor Philip Munday of James Cook University (JCU) has found it could also make fish less aware of - and even attracted to - predators.

They publish their research this week in the Proceedings of the National Academy of Sciences journal.

As part of the study, the researchers put clownfish and damselfish larvae into seawater equivalent to that which would be found if the atmosphere contained 700 ppm and 850 ppm of CO2 - levels that could be reached by the end of the century.

They found that after four days, half of the larvae in the 700 ppm group were less able to detect the smell of a predator, while all the larvae in 850 ppm group were actually attracted to the predator scent.

Damselfish larvae that were then released onto a reef were more active and behaved more boldly than normal, spending less time near shelter and more time near predators. They were also five to nine times more likely to die than normal fish born in 390 ppm conditions.

Profound implications

The results suggest this could have a huge impact on ocean biodiversity.

"Being attracted to the smell of a predator isn't likely to be a very good thing," Mr Munday said.

Professor David Booth, a marine ecologist at the University of Technology Sydney who was not involved in the study, says the behavioural choices made by young fish are thought to strongly affect populations.

"This finding of negative effects on such choices could have profound implications for the dynamics of fish populations," he said.

The researchers are now trying to pin down why acidification causes the fish to behave more boldly, as well as looking at the wider effects on population balance in reef ecosystems.

Mr Munday says, for example, different species could have different tolerances, and acidification could make predators more or less inclined to eat.

Professor Geoffrey Jones, also of JCU and the ARC Centre of Excellence for Coral Reef Studies, said the research took the level of concern about the effects of climate change on coral reef fish "to a whole new level".

"Without drastic action to cut emissions, all we can do is hope that fish will be able to adapt," Mr Jones said.

"However, given that the rate of CO2 increase is unprecedented, there are no grounds for optimism."

Climategate scientists cleared of manipulating data on global warming

Muir Russell report says scientists did not fudge data, but they should have been more open about their work

 Read the full text of the review here

Climategate' report - main findings

David Adam,  environment correspondent

The Guardian, Thursday 8 July 2010

The climate scientists at the centre of a media storm over leaked emails were yesterday cleared of accusations that they fudged their results and silenced critics, but a review found they had failed to be open enough about their work.

Sir Muir Russell, the senior civil servant who led a six-month inquiry into the affair, said the "rigour and honesty" of the scientists at the Climatic Research Unit (CRU) at the University of East Anglia (UEA) were not in doubt. His investigation concluded they did not subvert the peer review process to censor criticism and that key data was freely available and could be used by any "competent" researcher.

But the panel said the scientists' responses to "reasonable requests for information" had been "unhelpful and defensive". The inquiry found "emails might have been deleted in order to make them unavailable should a subsequent request be made for them" and that there had been "a consistent pattern of failing to display the proper degree of openness". Scientists also failed to appreciate the risk their lack of transparency posed to the university and "indeed to the credibility of UK climate science".

The controversy began when 13 years of emails from CRU scientists were released online last year. Climate change sceptics claimed they showed scientists manipulating and suppressing data to back up a theory of manmade climate change. Critics also alleged the scientists abused their positions to cover up flaws and distort the peer review process that determines which studies are published in journals, and so enter the scientific record. Some alleged the emails cast doubt on the findings of the Intergovernmental Panel on Climate Change (IPCC).

Announcing the findings, Russell said: "Ultimately this has to be about what they did, not what they said. The honesty and rigour of CRU as scientists are not in doubt ... We have not found any evidence of behaviour that might undermine the conclusions of the IPCC assessments."

The review is the third and final inquiry into the email affair, and effectively clears Professor Phil Jones, head of the CRU, and his colleagues of the most serious charges. Questions remain over the way they responded to requests for information from people outside the conventional scientific arena, some of whom were critics of Jones. "We do find that there has been a consistent pattern of failing to display the proper degree of openness, both on the part of CRU scientists and on the part of the UEA," said the report, commissioned by UEA at a cost of £200,000.

It also criticised the CRU scientists for failing to include proper labels on a 1999 graph prepared for the World Meteorological Organisation, which was the subject of an infamous email about Jones using a "trick" to "hide the decline". The panel said the result was misleading, though they accepted this was not deliberate as the necessary caveats had been included in the report text.

Acknowledging that the digital age brought a greater demand for openness and access to data, it concluded "like it or not, this indicates a transformation in the way science has to be conducted in this century." Edward Acton, vice-chancellor of UEA, said the university accepted the report's conclusion that it should have been more open. "The need to develop a culture of greater openness and transparency in CRU is something we faced up to internally some months ago and we are already working to put right."

He hoped the review would "finally lay to rest conspiracy theories, untruths and misunderstandings" that had been circulating, and that the "wilder assertions" about the climate science community would now stop.

Jones issued a statement which said: "I am, of course, extremely relieved that this review has now been completed. We have maintained all along that our science is honest and sound and this has been vindicated now by three different independent external bodies. There are lessons to be learned and I need time to reflect on them." Jones is to be director of research at CRU. Acton said this was "not a demotion but a shift in emphasis of role".

Ed Miliband, the former climate change secretary, said: "Muir Russell has given the world a clear message: we should not believe those who tell us that one string of emails undermines years of climate science. We should also learn lessons because maximum openness and transparency is the best weapon against those who want us to stick our heads in the sand as if climate change isn't happening. Now the world needs to step up the momentum again and get the deal that eluded us at Copenhagen."

Writing on Comment is Free, Dr Richard Horton, editor of the Lancet, who testified to the inquiry, said: "The Russell review has rejected all claims of serious scientific misconduct. But he does identify failures, evasions, misleading actions, unjustifiable delays, and pervasive unhelpfulness – all of which amounts to severely sub-optimal academic practice. Climate science will never be the same again."

Bob Ward of the Grantham Research Institute on Climate Change and the Environment, said: "It is clear that greater transparency is required in climate research because of the intense public interest in it, and its profound implications for society. However, it is also now very apparent that many so-called sceptics owe a huge apology to the public for having presented the email messages as evidence that climate change is a hoax carried out by a conspiracy of dishonest scientists."

Acton said: "CRU will be more closely integrated in the bigger school of environmental sciences and a key difference is to place some of the administrative burden that Phil had before this incident on the head of the school."

Bob Watson, chief scientific advisor to the department of environment, food and rural affairs, said that while it was clear scientists needed to be more transparent, he hoped the report would "draw a line under this episode so that the scientific community can begin to regain the trust of the public and continue to do its vital work on climate change, which remains one of the biggest challenges we face as a planet."

Myles Allen, head of the climate dynamics group at the University of Oxford, said: "What everyone has lost sight of is the spectacular failure of mainstream journalism to keep the whole affair in perspective. Again and again, stories are sexed up with arch hints that these "revelations" might somehow impact on the evidence for human impact on climate. Yet the only error in actual data used for climate change detection to have emerged from this whole affair amounted to a few hundredths of a degree in the estimated global temperature of a couple of years in the 1870s."

• Additional reporting by Christine Ottery

2010 on track to be hottest year

By environment reporter Sarah Clarke

ABC News Online, 10 July 2010

Last year was the second warmest on record, and this year could be the planet's hottest, according to a forecast from the Bureau of Meteorology, which says uncharacteristically warm conditions are being felt across the northern hemisphere.

The northern hemisphere is experiencing record high temperatures.

China has now issued a fresh heatwave alert after a week of soaring temperatures.

Parts of Northern Africa, the United States and the Middle East are also experiencing scorching heat, with some regions recording above 50 degrees celsius.

David Jones, a senior climatologist at the weather bureau's National Climate Centre, says the weather is uncharacteristic.

"Certainly the first six months of this year have been the hottest on record and it now looks like 2010 will be the hottest year on record," he said.

"We actually got into the low 50s for parts of the Middle East and Pakistan a couple of weeks back, so some extreme numbers, but more generally numbers approaching 40, 41. Beijing the other day just fell short of 41. We're seeing 40s right up and down the US eastern seaboard.

"Many of these are, if they're not record-breaking, they're getting very, very close to records."

He says such long runs of very high temperatures are uncharacteristic, but it is not entirely suprising, as the planet has experienced the hottest start to a year on record.

Complex story

Dr Jones says every year is different from the year before, but Australia is getting hotter.

"We have seen an increase in heatwaves in Australia in the last 30 to 50 years," he said

"The odds are, as we go forwards, we certainly will get more of them."

He says while some parts of Australia are experiencing cool conditions, northern Australia is having a warmer winter, and parts of the country are experiencing more unseasonal rainfalls.

"We've seen some record rainfall through parts of the Northern Territory, Queensland and WA," he said.

"What has actually slipped under the radar is the tropics have actually been really warm.

"So while it's been cold in the central parts, we've been seeing record high night time temperatures across the tropics.

"It's a pretty complex story out there; lots of extremes in the weather."

Global emissions targets will lead to 4C temperature rise, say studies

Studies predict major extinctions and collapse of Greenland ice sheet with temperatures rising well above UN targets

Juliette Jowit and Christine Ottery

guardian.co.uk, Monday 5 July 2010

See also 

The Age, 7 July 2010

The world is heading for an average temperature rise of nearly 4C (7F), according to analysis of national pledges from around the globe. Such a rise would bring a high risk of major extinctions, threats to food supplies and the near-total collapse of the huge Greenland ice sheet.

More than 100 heads of state agreed in Copenhagen last December to limit the rise in global temperatures to 1.5C-2C (2.7-3.6F) above the long-term average before the industrial revolution, which kickstarted a massive global increase in the greenhouse gases blamed for warming the planet and triggering climate change.

But six months on, a major international effort to monitor the emissions reductions targets of more than 60 countries, including all the major economies, the Climate Interactive Scoreboard, calculates that the world is on course for a rise of nearly double the stated goal by 2100.

Another study by Climate Analytics, at the Potsdam Institute in Germany, suggests there is "virtually no chance" world governments will keep the temperature rise to below 2C, and the rise is likely to be 3.5C (6.3F) by the end of the century.

In both analyses the current commitments suggest a much better outcome than the estimated business-as-usual temperature rise of 4.8C (8.6F), but are well above the 2C maximum the UN hoped would be agreed at the next major meeting this December in Cancún, Mexico – and even further from the 1.5C target many developing nations argue is needed to stop the worst impacts of climate change in their countries.

In its last assessment of the problem in 2007, the Intergovernmental Panel on Climate Change (IPCC) forecasts that a rise of more than 2C would lead to potential increases in food production, but an increasingly high risk of extinction for 20-30% of species, more severe droughts and floods, and a unstoppable "widespread to near total" loss of the Greenland ice sheet over very long time periods. However, at 4C it predicted global food production was "very likely" to decrease, "major extinctions around the globe", and near-total loss of Greenland's ice, precipitating 2-7m of sea-level rise in the long term. As temperatures rose, the severity of floods, erosion, water pollution, heatwaves, droughts and health problems such as malnutrition and diarrhoea diseases would also increase, said the IPCC.

"We're looking at a level which is much more extreme and profoundly dangerous," said Ruth Davis, chief policy adviser for Greenpeace. "It's arguable the UN process has become dangerously cut adrift from the science of climate change."

The Department of Energy and Climate Change said that, based on national offers of emissions reductions made in Copenhagen, the United Nations Environment Programme (Unep) and other bodies had calculated that it was possible to meet the 2C target, although this would depend on the targets set beyond 2020.

"There's more work to do if we're going to avoid a 2C temperature rise which is why we're pushing the EU to cut its emissions by 30%," said a DECC spokesman. "Keeping below 2C is still possible from the high end Copenhagen accord offers, but will require steeper action after 2020."

However, many experts said the much higher temperature-rise estimates were a cause for serious concern that emissions cuts proposed for Cancún were too low and not enough was being done to prepare for further cuts beyond 2020, even though there are still nearly six months of negotiations before the talks.

"We've made progress but we're clearly not headed where we need to be," said Andrew Jones, co-director of Climate Interactive, which is backed by several universities including MIT. "No one is talking about changing any of the 2020 proposals, so we should be worried." Climate Interactive's model is also backed by a panel of experts including Prof Bob Watson, chief scientific advisor to the UK's Department for Environment, Food and Rural Affairs (Defra), and a former head of the IPCC.

The Climate Interactive Scoreboard, for which researchers check daily for updates in emissions or other targets which would reduce pollution such as reductions in energy intensity or increases in renewable energy, makes a medium-range prediction of a 3.9C increase in temperatures, with a range of 2.3-6.2C (4.2-11.1F), based on committed targets, and a more encouraging 2.9C (5.2F) average, with a range of 1.7-4.6C (3.1-8.5F) based on "potential" commitments suggested but not enacted by many nations.

One of the major barriers to setting higher emissions cuts was a great many countries, including Canada and the EU, have said they do not want to increase their targets until the US sets significant reductions, which is proving hard for President Obama to achieve, said Davis.

Climate Analytics and Ecofys, under the banner of Climate Action Tracker, estimate a range of 2.8-4.3C.

The principal differences between the two calculations are that they use different models, and made different assumptions about what countries will do after their current targets expire, said Jones.

In both cases, there has been no improvement to the forecast outcomesince the experts assessed the prospects immediately after the Copenhagen conference.

The predictions will be particularly worrying for many watchers because the 2C target was based on research which suggested that at that level there was only a low to medium risk of key changes to the conditions in which humans survive; however an update of the "burning embers diagram" by the authors, published last year by the Proceedings of the National Academy of Sciences in the US, suggested that at 2C there greater risk in all categories, including a significant to high risk to unique and threatened ecosystems, of extreme weather events and a global distribution of the worst threats.

Turbine noise no health threat

ADAM MORTON

The Age, July 3, 2010

A FEDERAL government health body has dismissed claims that low-frequency noise from turbines causes health problems in people who live near wind farms.

A review of published scientific literature by the National Health and Medical Research Council found that wind farms caused no direct pathological effects and any potential impact could be minimised by following existing planning guidelines.

The review follows claims that infrasound, or low-frequency noise, causes ''wind turbine syndrome'', which includes symptoms of nausea, dizziness, heart palpitations and headaches.

Claims the symptoms are linked to wind turbines have been most prominently backed by New York pediatrician Nina Pierpont in her book Wind Turbine Syndrome: A Report on a Natural Experiment.

The health council review of 29 published studies and reports found Dr Pierpont's assertions were yet to be published in a peer-reviewed journal and had been heavily criticised by acoustic specialists.

The review found infrasound was constantly present in the environment due to ambient air turbulence, ventilation units, ocean waves, traffic and machinery.

''A survey of all known published results of infrasound from wind turbines found that wind turbines of contemporary design, where rotor blades are in front of the tower, produce very low levels of infrasound,'' it said.

The audible noise of a 10-turbine wind farm 350 metres away was found to be roughly equivalent to a quiet bedroom, and less than a busy office or a car travelling at 64 km/h 100 metres away.

The review found there was no evidence that shadow flicker from blades was likely to cause epileptic seizures or that turbines cause dangerous electromagnetic fields.

The Clean Energy Council said the review should put to rest claims that wind farms could make people sick.

Council policy director Russell Marsh said more than 100,000 turbines had been installed around the world over the past three decades. He said the study was consistent with a statement made by Victoria's chief medical officer, John Carnie, other international studies and acoustic research.

Randall Bell, president of the Victorian Landscape Guardians, said the review was effectively saying that hundreds, possibly thousands, of people around the world complaining of wind turbine syndrome were lying.

He said the health council review was consistent with the indifference of other government agencies to the plight of people near wind farms. ''Until you do get a different attitude one is inclined to be very sceptical about this [review],'' he said.