The EU has earned a lot of credit on the international climate scene. It has pushed through a roadmap to a second Kyoto deal at the Durban climate change summit, and stood firm on tugging global airlines into a carbon-pricing scheme.

More than anything it has demonstrated its good faith with a pioneering set of decarbonisation targets at home: the "20-20-20" goals. By 2020, the EU has pledged to cut greenhouse gas emissions by 20% of their 1990 level, and to increase the share of renewables to 20% of the energy mix. It also has a voluntary target to increase energy efficiency by 20% on 2005 levels, and an obligation to source 10% of its transport fuels from renewable energy sources by the same year.

"We're not waiting for talks to end in binding targets," the climate commissioner, Connie Hedegaard, said in Brussels, shortly before the Durban summit. "We're trying to move forward with our low-carbon roadmap, energy efficiency, discussing how we can increase efforts back home."

She had reason to sound confident. The EU's climate and environment directorates are staffed with some of the most talented and dedicated friends of the earth that you could find. But what if a culture of creative accounting, for reasons of political expediency, was robbing the targets they were working for of any credibility?

Of the EU's three 20% goals for 2020:

• Emissions reductions themselves are counted at the point of production and not of use, thus allowing an estimated 7% of Europe's carbon emissions to be outsourced to the developing world, through international trade. This oversight is rooted in the Intergovernmental Panel on Climate Change (IPCC)'s carbon-accounting rules, rather than Brussels'. But EU member states stick to these rules like glue, and they raise a question mark over any reported carbon dioxide reductions.

• Half of the EU's accounted increase in renewable energy uptake is expected to come from biomass, much of which some scientists fear may not reduce real emissions at all, even if Brussels counts it as doing so. Biomass can – and in the majority of cases may – come from unsustainable forest use in Europe and abroad, thereby increasing rather than reducing emissions. On current trends, the EU could run out of harvestable wood before 2020 and is said to be counting on energy savings to reduce Europe's overall power-consumption levels.

• But energy-efficiency objectives, as a non-binding measure, will almost certainly not be met. The EU is currently on track for around 9% energy savings – less than half the declared target. And even as civil servants gut the few paltry measures proposed in the energy efficiency directive to help it along, EU states are pushing for "early actions" to be "double counted".

With the commission's other 10% target for renewable energy in transport – which will mostly be met by conventional biofuels – the EU's own research suggests that it is unlikely to reduce emissions at all, despite the programme's exorbitant cost. Scientists again blame a "double counting" of emissions. Many commission officials are uneasy about the implications.

The EU is a trendsetter in global climate policy, and has the world's most ambitious climate goal: an 80-95% cut in CO2 emissions by 2050, measured against 1990 levels. Later this year, Brussels will announce new interim climate targets for 2030 and possibly 2040 as milestones along the way. The rest of the world will no doubt watch agog – or aghast, waiting for the plans to unravel.

But this is why any fears of a parallel with the run-in to the Eurozone meltdown need to be addressed now. Then, the EU's book-keepers approved billions of euros of bad loans to countries such as Greece, which had dressed up their public finances to make it appear as though they were meeting criteria when they were not. Greek number-crunchers reportedly used a known loophole in the EU's accounting system to "juke the stats".

If a similar culture of false accounting in the commission and the EU member states is in play now, it could eventually help produce a policy failure of equally catastrophic proportions, even if it is not immediately felt.

• Arthur Neslen is environment correspondent for European news service EurActiv