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Thursday 15 May 2008 (Updated Fri 16 May 2008)

RAPID ROUNDUP: Climate change: Huge analysis shows warming is changing the world (Nature) – experts respond

The most recent IPCC report concluded that anthropogenic climate warming is "likely" to have had a discernible effect on physical and biological systems. A large scale analysis published in Nature today goes even further to show that climate warming is in fact the overriding factor in changing the world's natural systems, outstripping the more modest effects of other factors such as deforestation and other land-use changes.

The research shows that in around 90% of cases, the trends are consistent with the predicted effects of a warming climate and that a vast array of physical and biological systems are being affected. The research team, which includes David Karoly from the University of Melbourne, concludes that the temperature increases observed at continental scales cannot be explained by natural climate variations alone.

The AusSMC has rounded up Australian experts to comment on this research. Feel free to use the comments below in your stories. If you would like to speak to an expert, or need a copy of the paper and media release, please don’t hesitate to contact us on (08) 8207 7415 or by email.

Professor David Karoly is one of the study’s authors and is from the School of Earth Sciences, University of Melbourne. David was also a lead author on the IPCC WG2 report.

“It was a real challenge to separate the influence of human-caused temperature increases from natural climate variations or other confounding factors, such as land-use change or pollution. This was only possible through the combined efforts of our multi-disciplinary team, which examined observed changes in many different systems around the globe, as well as global climate model simulations of temperature changes."

Andrew Lowe is Professor of Plant Conservation Biology at the University of Adelaide and Head of Science at the SA Department for Environment and Heritage’s State Herbarium and Biological Survey.

“This work is of global significance. It’s an integrated analysis of the biological and physical earth system changes due to climate change. The authors used a massive dataset and for the first time prove that changes in things such as glacier melt, bud burst flowering in plants, developmental time of insects and fresh water and marine community changes are occurring globally and can be assigned to global warming.

The analysis used innovative statistics- but all are from Northern Hemisphere locations (US and Europe) - data from tropical and sub tropical areas including most of Australia are notably lacking. There is a need to place more emphasis on monitoring biological and physical changes in these areas – nationally and globally.”

Dr Cynthia Rosenzweig is from NASA GISS in New York, and is the paper’s lead author.

“Humans are influencing climate through increasing greenhouse gas emissions and the warming world is causing impacts on physical and biological systems that are now attributable at the global scale and in North America, Asia, and Europe”

Professor Neville Nicholls is at the School of Geography & Environmental Science at Monash University and was a lead author of the IPCC Synthesis Report released in November 2007.

"People sometimes wonder if the warming reported by climate scientists perhaps just reflects cities growing bigger, or changes in the way we measure temperature. Rosenzweig and her colleagues used tens of thousands of time series of phenomena such as the timing of flowering or egg laying to test this. Most of their data were from well outside cities, and used nothing other than natural phenomena to 'measure' temperatures. The vast majority of these time series, in all inhabited continents, showed the changes you would expect in a warming world.

So, yes Virginia, 'global warming' truly is global".

Dr Roger Jones is from the Risk, Adaptation and Policy Team at the Centre for Australian Weather and Climate Research (a partnership between CSIRO and the Bureau of Meteorology). He was a Coordinating Lead Author on the IPCC WG2 report.

“This paper outlines an extremely robust case for linking a range of observed physical and biological changes to human-induced climate change, specifically warming. For data-rich regions, such as North America and Europe, the case is watertight. The data-set that was compiled for the IPCC Fourth Assessment Report also forms an extremely important observational baseline for monitoring change and from which to assess adaptation efforts. Unfortunately, the coverage of such data is not global and many regions of the world, including Australia, are not very well covered. Many of the regions that lack coverage are also thought to be highly vulnerable to the impacts of climate change. In many of these regions, biological changes are not so tightly coupled to temperature but are linked to more complex interactions with a range of climate variables, especially those that are moisture-related. This shows the need to put more resources into monitoring environmental change, because we cannot properly assess the vulnerability of natural systems, or progress in adaptation, without it.”

Professor Barry Brook is Director of the Research Institute for Climate Change and Sustainability at the University of Adelaide.

"The new Nature by Rosenzwieg, Karoly and co-authors is a statistical integration and summary of the scientific literature on observed changes to physical and biological systems on Earth. In its broad approach and the data sets examined, it uses similar methods to that taken in the Working Group II report of the IPCC 4th Assessment report. But for those people who want the main facts without needing to wade through the many hundred pages of the official IPCC WGII report, this paper is a good summary of the main impacts and adaptation for climate change. As such, it is a must read.

There are a couple of really interesting results. One is that the evidence for change in the expected direction if climate change was having an effect - that is, changes in physical (ice sheets, stream flow, coastal erosion etc.) and biological systems (timing of breeding events, shifting species ranges, population declines etc.) - is overwhelming. Around 90% of all reasonably long-term observations show changes consistent with global warming and associated effects. There is always considerable natural variability in response of individual species, physical process and so on. Therefore, this level of concordance is really quite remarkable, and all the more so when we consider that there has been only ~0.75C of temperature change so far, yet the expectation for this century is four to nine times that amount. So these changes are only a minor portent of what is likely to come, especially if we continue on our carbon profligate pathway.

The other interesting point is that Australia is only sparsely represented. There are very few long-term datasets from Australia or New Zealand. In biological systems, for instance, there are 22 studies from Australia and a staggering 28 thousand from Europe (there are also relatively few from Asia, Africa and South America). Clearly Australia, as a science-savvy nation, needs to foster a broad-based system of biophysical monitoring, including the establishment of a large number of long-term monitoring sites and a stronger emphasis on providing resources to database and analyse our existing records (which are currently warehoused but hardly used or referenced for any evidence-based decision making). This is a great challenge for Australia, if we are to predict future climate change impacts with any degree of confidence and be in a reasonable position to build resilience into natural and human systems. Let's hope future government Budgets and funding initiatives pursue this urgent imperative with the required gusto. We've no time to waste."

Dr Paul Beggs is a Senior Lecturer in the Department of Physical Geography at Macquarie University, Sydney

"'This article is one of the most significant since the Intergovernmental Panel on Climate Change published its landmark Fourth Assessment Report in 2007.  It highlights the fact that climate change is already having physical and biological impacts around the world.  These are of great concern in their own right, but also because they are leading to many adverse impacts on human society."

Professor Nathan Bindoff is a physical oceanographer and Director of the Tasmanian Partnership for Advanced Computing (TPAC). Partners include the University of Tasmania, CSIRO Marine & Atmospheric Research and the Antarctic Climate and Ecosystems CRC. He was a Coordinating Lead Author of the IPCC AR4 Working Group 1 chapter on oceanic climate change and sea level observations (Chapter 5).

“I marvel at the diversity of environmental data recorded over a relatively short period of time that can be related to the climate change. The scope of the analysis across such a range of different non-physical variables illustrates the broad reach of the climate change on the environment. It is assessments of this type that give un-ambiguous observational evidence for effects of increasing emissions on the environment.”