Friday, March 26, 2010

Australia lagging in clean energy investment

By environment reporter Sarah Clarke

ABC News Online, Fri Mar 26, 2010
A global analysis of clean energy investment has found that Australia ranks 14th on the list of G20 countries, behind Mexico and Turkey.
The US-based Pew Foundation study found China was the biggest investor in projects such as renewable energy plants - including solar and wind - investing $34 billion last year.
Australia invested $1 billion, which is up by 50 per cent on 2008, while the United States spent $18 billion.
John Connor from the Climate Institute says the Federal Government needs to drive greater investments in projects like renewable power.
"It's a tragedy that we have got such rich resources in renewables in solar, wind, biomass, waves - you name it," he said.
"But without clear directions, and the course of the political squabbling that we've seen, we're not seeing that investment come forward.
"We need a limit in price on pollution and we need other incentives as well."
Globally clean energy investments have increased by 230 per cent since 2005.
Renewable power produces 6 per cent of global energy needs.

Climate can-do in Cancun?

IF THE Copenhagen climate summit was a complete failure, nobody told the President of the Maldives. As the gavel fell on a marathon all-night final session to end two frustrating weeks in the Danish capital last December, Mohamed Nasheed punched the air to celebrate the Copenhagen Accord - a limited, non-binding agreement that the United Nations chose not to adopt.
Instead, the UN chose merely to note its existence, leaving what was widely considered a weak deal with an uncertain legality. Even assuming it had been adopted, it was nothing like enough to counter the scientific projections that the Maldives' 26 low-lying atolls would be wrecked by rising sea levels.
Nasheed takes these warnings seriously. He has raised the idea of his country having to buy land from another nation to guarantee it a future. Amid the furious lobbying in the weeks before Copenhagen, his cabinet pulled off a most eye-catching PR stunt, donning scuba gear and posing for a photo on the ocean floor.
At the conference itself, this articulate former prisoner of conscience who led the fight to transform the Maldives from an autocracy to a democracy, again took on the role of the voice of the voiceless, fighting for the rights of the most vulnerable.
Yet here he was, jumping for joy over a deal that appeared to put this worst-case scenario in the frame.
'''You have to remember what was happening in the conference centre at that point,'' Nasheed told The Age this week.
''If Copenhagen had ended in failure, there was a danger that the entire UN process on climate change would unravel. We had to salvage something. The Copenhagen Accord was a lowest-common denominator agreement, but it kept the process - and the world - together.''
Three months on from Copenhagen there is little air punching, but Nasheed's interpretation is gaining traction.
No one pretends Copenhagen was a success; the farcical final 24 hours, in which Chinese Premier Wen Jiabao studiously avoided being in the same room as US President Barack Obama, remains a testament to how unrealistic and poorly organised the conference was. But while it may be the forced optimism of those who have to pick up the pieces, there is a growing belief internationally that it was not the disaster it initially appeared.
Despite being pulled together in a backroom deal between Obama and leaders from the four BASIC developing countries - Brazil, South Africa, India and China - the adoption of the accord was blocked by only six nations. It could easily have been abandoned at that point. Many countries resented that it had been thrashed out and imposed on them outside the formal UN negotiation process. But 114 countries have backed up their initial support by formally associating themselves with the accord and 74 have submitted targets to cut or slow greenhouse gas emissions. Nearly 80 per cent of the world's emissions are included.
While no ground was made on emissions targets at Copenhagen, Nasheed says the accord had some points worth fighting for. Billions of dollars were promised to help the poor tackle climate change. A deal was in sight to limit emissions from deforestation. Crucially, for the first time major developing countries such as China and India volunteered on an international stage to slow emissions - a shift that would have been unthinkable just a few years ago. ''It is a step forward, albeit a small one,'' Nasheed says.
Howard Bamsey, Australia's chief climate envoy and a veteran of UN negotiations, says the level of international support suggests the accord has moved on from its ugly birth to become a "living, vital and implementable" document.
Along with the progress highlighted by Nasheed, it broke ground by bringing developed and developing nations together into the same document and forging an agreement that the world needed to avoid 2 degrees' warming to prevent dangerous climate change. ''Each of these points might look quite small in itself, but when they are made together the foundations involved have changed,'' Bamsey told a recent Melbourne conference. ''Frustrating as the progress is, it is much faster than we have seen in other parts of the UN.''
What this growing optimism means for hopes of a future deal is difficult to read. The strength of countries' commitment will become clearer in two weeks, when climate diplomats from 192 nations gather in Bonn for the first formal post-Copenhagen meeting. They will turn up with a set of non-binding targets that if acted on, will, analysts estimate, still mean a temperature increase of at least 3 degrees this century - well beyond the common shorthand for a safe climate.
Australian National University environmental law academic Andrew Macintosh says the chance of avoiding 2 degrees' warming is ''diminishing rapidly'', and would require a Herculean effort after 2020, given current proposals.
But things have improved - we were looking at a 5 degree temperature rise; it may now be less than 4.
Given the hostility that bubbled over on the final day at Copenhagen, the diplomats will also turn up with a lack of confidence that countries can be trusted to do what they say they will do - particularly the US, still battling to agree on a climate bill that can get through Congress.
One thing is clear: after the over-inflated hype of Copenhagen 2009, expectations for the next big meeting - in the Mexican resort city of Cancun in December - will be down with the earthworms. Experts believe it may be another three years, at Rio de Janeiro in late 2012, and with the mandate of another US presidential election, before the possibility of a binding treaty to tackle climate change is revisited.
The major issue at Bonn will be grappling with how to deal with a rearranged world, one in which the grand gestures of the European Union - long seen as the leader in climate talks - have been supplanted by the hardened pragmatism of the US and China. The stand-off between the north and south - over whether the wealthy are really taking responsibility for their historic emissions by making significant cuts that will give the developing world a chance to break free from poverty - began to fracture at Copenhagen. At times the US was at odds with the EU and Japan, both of which had to contend with the unfamiliar feeling of being marginalised on the chaotic final day.
Larger fissures opened up within the G77 bloc of developing countries, with the giants in the BASIC group under pressure from an increasingly vocal collection of the least developed countries and small island states, who just want all the major emitters, rich or emerging, to get on with it. An angry group of African nations was seen to be spoiling on China's behalf, while the oil-rich nations of the Middle East opposed anything that would limit their ability to sell their resource.
On the final day the so-called ALBA group of socialist Latin American countries, led by Hugo Chavez's Venezuela, appeared hell bent on tearing down any hope of even a weak consensus. The G77 remained united on at least one point - that the industrialised nations have not lived up to their promises, and should be doing more.
Geopolitics aside, the other shift under way is the rise of clean technology, regardless of the political roadblocks. More money is being spent on low-carbon energy than on dirty fuels such as coal, creating a new mainstream constituency within large corporations.
A vocal minority aside, governments know this. They just don't quite know how to handle it. ''If anyone tells you they know what the world looks like in climate change diplomacy right now, they're lying to you,'' says Climate Institute deputy chief executive and long-time negotiators-watcher Erwin Jackson.
It leaves countries such as Australia and the US, which have legislation on the table but yet to be passed, in an uncertain position. Momentum for the international climate talks will have to come from what each country does at home. But climate change appears to be sliding from the agenda in Canberra, with no chance the emissions trading bill will be passed this year. The government has committed to a 5 per cent cut in emissions below 2000 levels by 2020, but stressed it was unlikely to go beyond that in the short term, adding what appeared to be new conditions for it to make a 15 or 25 per cent cut when it formally signed up to the accord in January. Most tellingly, it suggested that Australia would not increase its target unless climate legislation passed the US Senate.
Plenty of climate analysts believe this shifted the goalposts. Australian National University economist Frank Jotzo, a senior adviser on the Garnaut Climate Change Review, this week released an analysis that found Australia should be taking on a 15 per cent target to live up to the conditions it put forward last year. This view is broadly backed by other experts, including government climate adviser Ross Garnaut and Melbourne University environmental studies academic Peter Christoff.
Meanwhile, the world is still waiting to see what comes out of the US Congress. Heavy resistance to emissions trading, known in the US as cap-and-trade, has prompted a cross-party compromise bill that is expected to focus on boosting renewable energy and forcing emitting industries, such as power and transport, to pay for their carbon dioxide emissions in different ways. Climate change will not be mentioned much; the bill will be pitched as a means to create jobs and reduce dependence on oil. Whether this will win the support of the Senate - and international observers - is an open question.
The US Congress, and arguably Obama's preoccupation with the economy and healthcare, was a major roadblock at Copenhagen, but so was China's unwillingness to negotiate. For most of past year, no one took the world's largest emitter seriously when it said it would not be part of a binding deal, and that it expected the traditional industrialised powers to do much more than they had promised.
There has been plenty of commentary about China's obstructionist tactics, most notably from British Climate and Energy Secretary Ed Miliband. In an opinion piece written the day after the conference ended, he accused China of vetoing an agreement that the world cut emissions in half by 2050, despite this position having the support of most developing countries. It also blocked a commitment that industrialised countries make an 80 per cent cut by mid-century. It objected to what these goals implied - that Beijing would eventually have to take on its own reduction target if dangerous change was to be avoided. Instead China pushed for the developed nations to make an unworkable 213 per cent cut on 1990 levels by 2050.
China has a world-leading renewable energy program, an advanced energy efficiency target and a once-unthinkable target of reducing emissions per unit of GDP by 40-45 per cent. But its soaring economic growth depends on coal and it has no plan to slow that.
Unsurprisingly, Beijing rejects claims it deliberately wrecked talks to embarrass Obama and guarantee a terrible deal that would be blamed on Western leaders. A report by a Chinese government research institute leaked to The Guardian said it spent the fortnight resisting a conspiracy by developed countries to abandon the existing Kyoto Protocol, which puts the onus for cuts on the rich.
The West and a growing number of poor nations respond that without China playing a greater role there is no solution to climate change. The argument about the definition of ''common but differentiated'' responsibility to clean up the mess remains the biggest roadblock to a meaningful deal. But there are broader issues at play here than just climate change, as China looks to gain leverage over the US.
Given this, Cancun is expected to focus on making progress where possible, including cutting tropical deforestation, giving the poor access to clean technologies, developing a climate finance system and setting rules for carbon markets.
But Nasheed stresses the increasingly dire warnings of scientists must not be allowed to be swept aside. He says pragmatism must not mean a lack of urgency in domestic steps to cut emissions. ''Cancun needs to recognise the rights of vulnerable countries like the Maldives to exist,'' he says.
''It is inexcusable to condemn a nation - not to mention the planet - to death because some countries want to carry on burning coal.''
Adam Morton is environment reporter.

Monday, March 22, 2010

Environment Hacked climate science emails Lord Oxburgh to head new UEA inquiry

Former chair of the science and technology select committee will lead a panel to reassess the scientific papers produced by the Climatic Research Unit

David Adam, environment correspondent, Monday 22 March 2010

The University of East Anglia has asked Lord Oxburgh, former chair of the House of Lords science and technology select committee, to head a new inquiry into the results produced by the climate scientists at the centre of a media storm.

Oxburgh will lead a panel of scientists that will reassess the scientific papers produced by experts at the university's Climatic Research Unit (CRU). The work of the CRU has been subject to intense scrutiny since thousands of emails from its scientists were released online in November.

Oxburgh said: "The shadow hanging over climate change and science more generally at present makes it a matter of urgency that we get on with this assessment. We will undertake this work and report as soon as possible."

The university has already set up a separate inquiry into the way the CRU scientists behaved, led by Sir Muir Russell. The new investigation will look at the results they published in scientific journals.

Trevor Davies, pro-vice chancellor for research at the university, said: "CRU's scientific papers have been examined by scientists from other institutions through the peer review system before being accepted for publication by international journals. We have no reason to question the effectiveness of this process. Nevertheless, given the concerns about climate research expressed by some in the media, we decided to augment the Muir Russell review with an independent assessment of CRU's key publications in the areas which have been most subject to comment."

The members of the panel are: Prof Huw Davies at ETH ZurichProf Kerry Emanual at MITProf Lisa Graumlich of the University of Arizona,Prof David Hand of Imperial College London, and Prof Herbert Huppertand Prof Michael Kelly at the University of Cambridge.

Brown coal emissions rise 10% in a decade

GREENHOUSE gas emissions from Victoria's brown-coal fired power stations increased nearly 10 per cent over the past decade despite government programs designed to promote renewable energy.
It reflects that more than three-quarters of the new electricity generation in Victoria to meet increasing national demand since 2000 comes from burning brown coal, the dirtiest major source of electricity.
An analysis by consultants Green Energy Markets found generation at the four major Latrobe Valley brown-coal fired plants has grown steadily despite the advent of renewable energy targets.
The report comes as green groups coalesce behind a campaign to close Hazelwood power station - Australia's most greenhouse gas-intensive power plant - by 2012. Sections of the ALP are believed to be keen on an announcement about Hazelwood before the November state election.
Commissioned by Environment Victoria, the analysis found coal was responsible for 91.5 per cent of energy generated in the state last year.
Renewable energy sources contributed 5.4 per cent, up from 4.5 per cent a decade earlier. While wind power grew exponentially, the increase was offset by a decline in hydroelectricity due to drought.
Gas-fired power - widely considered a viable medium-term option to reduce emissions - contributed 3 per cent.
Environment Victoria campaigns director Mark Wakeham said the analysis showed the only way to reduce the state's emissions was to replace one of the large coal stations.
The power industry has ridiculed the 2012 closure date nominated by climate activists at a summit earlier this month, saying there is not enough generation capacity to replace it.
Hazelwood's owner, International Power, is open to a phased shutdown of the plant if it was paid a tariff based on its pre-emissions trading value.
Victorian government spokesman Shaun Inguanzo said the future of power stations such as Hazelwood would be determined by its owners or in Canberra, where the Rudd government's proposed emissions trading scheme would give an incentive to cut emissions. The scheme, opposed by all non-government parties, is due to be introduced to the Senate for a third time in May.
Opposition energy spokesman Michael O'Brien did not respond to questions about Hazelwood's future.
The latest report follows a Climate Group analysis that found national emissions were lower this summer than last despite increased generation at Victoria's brown-coal plants.

Thursday, March 18, 2010

City's hottest 100 - record run of warm days

MELBOURNE'S temperature has topped 20 degrees for the past 100 days straight, the longest stretch of its type in more than 150 years of measurement.
Yesterday's maximum of 31 degrees continued a run of 20-plus degree days that began on December 9 last year.
It has smashed the record of 78 days with a maximum of more than 20 degrees in the summer of December 2000-01.
The Bureau of Meteorology's head of climate analysis and prediction, David Jones, said forecasts suggested the string of days warmer than 20 degrees could extend for at least another seven days.
He said it was part of a longer warm period across the state extending back to last winter.
''The whole of Australia has been exceptionally warm, and the mean temperature across Victoria over the past nine months has been the warmest on record,'' Dr Jones said.
''It continues this storyline of a planet that continues to warm.''
The British Met Office has predicted that it was more likely than not that 2010 would be the world's hottest year on record due to global warming linked to greenhouse gas emissions and a warming of the tropical Pacific Ocean due to El Nino.

Wednesday, March 17, 2010

Climate science: dealing with the (minor) errors

Regardless of claims by polluters and sceptics, the IPCC's science is overwhelmingly sound, writesMelanie Fitzpatrick from the Union of Concerned Scientists in Washington
Inside Story, 08 March 2010
OVER THE PAST few months, the Intergovernmental Panel on Climate Change has been attacked for minor errors in its landmark 2007 report on climate change. These attacks have underpinned an intensified campaign against the IPCC across the western world. Here in the United States legislators and state attorneys-general are trying to use these flaws to thwart the Obama administration's attempts to introduce policies to reduce emissions.
The IPCC has said it will review its process for creating reports in light of the few errors that have been found. If carried out with rigour, transparency and independence, such a review will confirm and strengthen the IPCC's commitment to robust scientific assessment, and restore public confidence that has been shaken by an aggressive campaign to sow confusion about climate science.
Along with the manufactured controversy over stolen emails – driven by ideologues and anti-science bloggers who would rather attack scientistspersonally than grapple with substantive science – the recent attacks on the IPCC have given people already opposed to action yet another excuse to ignore the science. Those who choose to mischaracterise the scientific evidence about global warming are attempting to confuse the public and distract policymakers from addressing this issue. No matter how strong the science is, these well-funded contrarians would continue to oppose any policies that would make the oil and coal industries deviate from business as usual.
Overall, the IPCC's conclusions remain indisputable. Climate change is happening now and human activity is causing it. Nations around the world will need to adapt to unavoidable climate impacts, including sea-level rise, changes in precipitation, disruptions to agriculture and species extinctions. But if we reduce our emissions dramatically, we can still prevent the worst effects of climate change.

The IPCC is the world's leading body for assessing climate science. At the centre of the debate is the IPCC, the world's leading body for assessing climate science. Established in 1988 by the World Meteorological Organization and the United Nations Environment Programme, it is the organisation through which climate experts from around the world synthesise the most recent climate science findings every five to seven years and present their report to the world's political leaders. The panel's first report in 1990 spurred governments to create the United Nations Framework Convention on Climate Change, which remains the main body for international climate negotiations.
The IPCC's 2007 report is the most comprehensive synthesis of climate change science to date. Experts from more than 130 countries working over six years contributed to the assessment. More than 450 lead authors received input from more than 800 contributing authors, and an additional 2500 experts reviewed the draft documents.
The inclusive and transparent process by which IPCC assessments are developed, reviewed and accepted by experts and governments helps ensure the scientific credibility officials need when they formulate climate policies. As with any human endeavour – and especially given the size and coverage of the IPCC reports – errors are possible. They do not undermine the overall conclusions, which are subject to an exhaustive review process. It is a testament to the quality of the IPCC that errors have been few and, when identified, that they have been corrected. A concerted effort to improve the quality of the IPCC process is welcome but does not imply any serious deficiency in the content of the group's 2007 report.
Instead of exposing the scandal of unfounded attacks on scientists and highlighting how minor mistakes in the IPCC report have been outrageously exaggerated, the mainstream media has largely aided attacks on highly respected and competent climate scientists. That's unfortunate. When it comes to science reporting, journalists should emphasise what scientists do know and fulfil their mission to educate the public. Scientists don't deserve the same treatment journalists reserve for he said/she said reporting on political issues. And framing scientific issues as conflicts rarely enhances public understanding of science.
Let's consider the actual claims against the IPCC in detail. Most have been directed at the second volume of the 2007 IPCC report, "Impacts, Adaptation and Vulnerability."
The Himalayan glaciers: Chapter 10 of this volume includes a statement that the likelihood that Himalayan glaciers will disappear "by the year 2035 and perhaps sooner is very high." It is not clear how this unsupported assertion made it into the report, as it was openly challenged by some researchers during the review and editing process.
The claim is part of the full review of climate science and impacts provided in the dense, 3000-page report, but is not mentioned in its highly visible summaries for policymakers – presumably because the panel did not consider the claim to be reliable enough for its policymaker summary. The statement in the summary is much less specific. "If current warming rates are maintained," it states, "Himalayan glaciers could decay at very rapid rates."
What should not get lost is the fact that glaciers around the world are melting rapidly. A 2005 global survey of 442 glaciers from the World Glacier Monitoring Service found that only twenty-six were advancing, eighteen were stationary, and 398 were retreating. Overall, about 90 per cent of the glaciers scientists have measured are shrinking as the planet warms.
Glaciers are an important water supply for many people. And new analysesindicate that the shrinking land-based ice could contribute to a sea-level rise of 80 cm by the end of the century; although two metres is less likely, it is still physically possible.
The Amazonian rainforests: A sentence in chapter 13 of the second volume states: "Up to 40 per cent of the Amazonian forests could react drastically to even a slight reduction in precipitation; this means that the tropical vegetation, hydrology and climate system in South America could change very rapidly to another steady state, not necessarily producing gradual changes between the current and the future situation."
In other words, global warming may be putting the Amazon basin at risk of more frequent and severe droughts. In drought years, trees are more likely to die and forests become more susceptible to fires. In wet years, fires often stop at the forests' edge because the forest soil is so moist.
In this case, the science is right, but the passage gets its citations wrong. It refers to a report from the World Wildlife Fund and the International Union for Conservation of Nature (a body that includes more than 1000 government and non-government organisations and nearly 11,000 volunteer scientists in more than 160 countries). But the 40 per cent figure is from a different source: peer-reviewed papers written by Dan Nepstad, a senior scientist at the Woods Hole Research Center on Cape Cod, and his colleagues. A simple change in citation would very effectively have short-circuited this criticism of the report.
Nepstad and other researchers confirmed the link between drought and fire in papers published after the IPCC's deadline for research that could be included in this section of the 2007 report.
Hurricanes: The 2007 IPCC report is also clear about how climate change would affect hurricanes. It concludes that hurricane intensity worldwide is likely to increase, and that there could be fewer weak hurricanes. The science linking climate change to increased severity of extreme weather is well-substantiated in peer-reviewed literature.
Even so, some contrarians have recently cited another, older controversy to try to give the false impression that these findings are in question. That controversy centres on how the 2007 report characterises the economic cost of an increase in severe weather. Contrarians point to a complaint by Roger Pielke Jr., a University of Colorado environmental studies professor, that the report misrepresents the reasons why economic losses from natural disasters have significantly increased over the years. Pielke says that the primary drivers for increased costs are economic factors, such as changes in wealth and population along the coasts.
The IPCC report does not dispute that fact, and it prominently cites Pielke's research. Chapter 7 of the second volume also refers to one study that suggests that factors other than economic ones may be driving costs, but includes a number of caveats in that citation. This is in keeping with the IPCC's task of presenting a balanced view of the literature. Specifically, the report concludes in its "Summary for Policy Makers": "Costs and benefits of climate change for industry, settlement [cities and towns] and society will vary widely by location and scale. In the aggregate, however, net effects will tend to be more negative the larger the change in climate." And it found: "Where extreme weather events become more intense and/or more frequent, the economic and social costs of those events will increase, and these increases will be substantial in the areas most directly affected."
Pielke specifically objected to the fact that the IPCC includes unpublished material on the economic costs of natural disasters in its 2007 report. But this practice is not unusual for the IPCC. The panel's procedures state that "it is increasingly apparent that materials relevant to IPCC reports, in particular, information about the experience and practice of the private sector in mitigation and adaptation activities, are found in sources that have not been published or peer-reviewed (e.g., industry journals, internal organisational publications, non-peer reviewed reports or working papers of research institutions, proceedings of workshops, etc)." The IPCC provides guidelines for the inclusion of such research, including clear citation. In any case, more published research is needed on the economic costs of climate change.
The urban heat island effect: Climate contrarians are falsely claiming that Eastern Chinese temperature data first published in a 1990 Naturepaper is compromised by the "urban heat island" effect. The term refers to the fact that buildings and asphalt are darker than surrounding countryside, often making cities and population centres hotter. Scientists have studied this effect since the mid-1800s and it is extensively referenced in the scientific literature. Overall, climate science indicates that the urban heat island effect has no bearing on global temperature trends and is insignificant compared to other adjustments routinely made to make temperature records more accurate.
When scientists measure global warming, they examine how much temperatures have changed over time. For instance, an urban station may have warmer thermometer readings compared with a rural station in the region, but global warming will cause temperatures to rise at both stations. To determine trends, scientists compare the difference between the temperatures at stations today and their average temperatures in the past.
Scientists worldwide, including those at leading American institutions, routinely correct station data for changes such as shifts in station location, different elevation, different time of daily observation, different latitudes, and instrument changes over time. For example, after such adjustments for stations across the United States, there was no detectable difference between urban and rural stations comparisons in each region.
The 1990 Nature paper has since been backed up by other studies. And Eastern China, meanwhile, is warming in a way that is consistent with the rise in global average temperatures.
Global warming is here and it's real. No amount of cherry-picking from the IPCC report will change that reality. Unfortunately, polluting industries and their allies are desperate to attack the IPCC and climate scientists generally. But that is only because they are losing. Here in the United States the public still supports comprehensive climate policy and an international climate treaty. President Obama is prioritising administrative action on climate change. And US senators will soon unveil their proposal for dealing with global warming.
We are still moving forward on climate change, even as polluting industries and their allies try to drag us backward. •
Melanie Fitzpatrick is a climate scientist with the Climate Program of the Union of Concerned Scientists. She worked for many years with the Australian Antarctic Program and in the Earth and Space Sciences Department at the University of Washington in Seattle.

Butterflies offer climate warning

The Age, March 18, 2010
SCIENTISTS have shown for the first time that man-made climate change is the direct cause of changes to the life cycle of a native Australian animal species.
Researchers have found that because of a rise in temperature, caused by an increase in greenhouse gas emissions by humans, the common brown butterfly now emerges from its cocoon 10 days earlier than it did 65 years ago.
"This is the first study in Australia, and one of the first studies around the world, that has linked changes in a natural system to regional climate change, and shown that the change in regional temperatures are due to increases in greenhouse gases in the atmosphere,'' said an author of the study, David Karoly, of the University of Melbourne.
Until now, many studies have only been able to demonstrate "links" between climate change and observed changes in flora and fauna. It has been hard to prove that climate change was the direct cause of such changes.
In the case of the brown butterfly, observations around Melbourne over the past 65 years have suggested it has been emerging earlier in spring each year. The butterfly is also found in South Australia, and the east coast of NSW.
Melbourne's weather over that period has been getting warmer, said the lead author, Michael Kearney, also of the University of Melbourne, whose research is published in Biology Letters.
To determine if the two changes were linked, Dr Kearney and his graduate student measured how fast a group of common brown caterpillars developed at different temperatures. They then compared their lab experiments with temperature records for Melbourne over the past 65 years, to predict when the butterflies would have emerged each year.
Dr Kearney said these predicted emerging times ''matched'' the actual butterfly emergence times that had been observed and recorded by scientists.
It was then left to the leading climate scientist, Dr Karoly, to discover if the rise of almost 1 degree since 1944 as recorded by the Bureau of Meteorology was caused by greenhouse gas emissions released by humans.
Using multiple climate models, Dr Karoly was able to show that the increase in temperature observed in Melbourne was outside the range of natural climate variability. The rise in temperature could be explained only when the effect of greenhouse gas emissions were added to the models, he said.
Dr Kearney said man-made climate change probably had a similar effect on other butterfly species.