But scientists who have analysed pledges to the Accord made by mid-April 2010 have branded them and the Accord's aims for impacting climate "a snapshot of dissonant ambitions". What's more, they say the ambition level of the current pledges for 2020 and the lack of any agreed goals for 2050 mean that the Accord is unlikely to limit temperature rise to less than 2 °C, a level agreed by many as the threshold for "dangerous" climate change.

"Our work gives a strong and solid indication that the international community urgently needs to come together to form an ambitious global agreement if we are to limit temperature increase to below 2 °C or to 1.5 °C in the long term," Joeri Rogelj of the Potsdam Institute for Climate Impact Research, Germany and ETH Zurich, Switzerland, told environmentalresearchweb. "In making their pledges, many countries indicated a willingness to do more, should others do so as well – this tells us that it is very likely that only with a legally binding agreement will states be willing to implement stronger mitigation action."

Nations are due to resume negotiations on 4 October in Tianjin, China, in the build-up to another round of talks in Mexico in late November.

Rogelj and colleagues from the Potsdam Institute for Climate Impact Research; Climate Analytics, Germany; Ecofys, Germany; Danish Meteorological Institute; and Swiss Federal Institute for Forest, Snow and Landscape Research used a reduced-complexity climate model to come up with probabilistic estimates of the effect on climate of emissions scenarios associated with the Accord.

The study showed that without revision of pledges and the removal of loopholes, the Accord could result in temperatures rising by up to 4.2 °C, as well as oceans acidifying to the extent that coral reefs and marine-shelled organisms are in serious trouble.

"Going beyond a mere aggregation of pledges, our study contains a detailed assessment of so-called loopholes, i.e. 'banked' emission allowances and 'land use, land-use change and forestry' (so-called LULUCF) credits," said Rogelj. "Thus, it provides some added benefit by clearly spelling out the additional accounting options that could further deteriorate the already unambitious 2020 emission pledges."

According to Rogelj, after the UNFCCC COP15 Summit in Copenhagen, a simple question deserved a well-founded scientific answer: where is the Copenhagen Accord going to bring us? "We decided to apply a sophisticated and detail-rich methodology that combines meticulous accounting of greenhouse-gas emissions on a country level with a representation of uncertainties in policies, emissions and the climate system," he said. "Only such an approach can give a solid scientific understanding of the range where we might end up, both in terms of emissions in the nearer term and for global climatic consequences over the 21st century."

Rogelj believes that only such an approach can give a solid scientific understanding of the range where we might end up, both in terms of emissions in the nearer term and global climatic consequences over the 21st century.

Many developed countries, such as the US and member states of the European Union, have set themselves very low targets; they're aiming to cut carbon emissions by just a few percent relative to 1990 levels. Japan and Norway, on the other hand, stand out as rare examples of developed nations with relatively ambitious targets; Japan is aiming to lower its emissions by 25% compared to 1990 levels and Norway is aiming for 30–40% cuts.

But even if nations made a commitment to cut emissions by 50% by 2050, there would still be a less than 50% chance of keeping temperature rise below 2 °C, say the researchers. Currently the Accord lacks any targets for 2050, which many regard as a serious shortcoming, although it does mention a possible strengthening of the temperature target to 1.5 °C in 2015.

The researchers are proud that the study uses a robust, peer-reviewed scientific and statistical approach to project atmospheric concentrations, global mean temperatures and their uncertainties, and that it analyses the detrimental effects of carbon dioxide in terms of both projected global mean temperature increase and of ocean acidification. "We also look at 2020 emission levels that could be called '2 °C compliant' and their implications for subsequent global reduction rates, something that has not been done in-depth before – and should be done in more detail in the future," said Rogelj.

Next the team plans to look in more detail at the climate and policy consequences of slow or late action, and also at scenarios that can limit warming to below 1.5 °C.

"While the global climatic consequences that are to be expected despite the Copenhagen Accord are becoming clearer, it is somehow paradoxical that the political will to act appears to be declining," said Rogelj. "Reasons for this may be that either policy-makers are experiencing difficulties in relating global climatic consequences to their own situations or because they are relying upon the scientifically weak assumption that returning to safe levels after a late peak in emissions is a feasible option."

So the team's future work will attempt to link specific and more tangible regional climate impacts to climate policy decisions. "We hope this will help policy-makers to understand better the importance of their decisions," explained Rogelj. "Exploring the behaviour of the climate system after a high peak in emissions will help understand the risks and uncertainties better, and thereby also, we hope, provide climate policy with invaluable insights."

Writing in ERL the researchers say that "with the negotiation mandates having been extended to the end of 2010, committing to higher ambitions and agreement by all parties still remains possible".