The Lima conference is intended to deliver the first draft of an accord to cut carbon emissions and stave off dangerous climate change, which is expected to be signed at a UN conference in Paris next year.

Speaking on condition of anonymity, a senior EU official in Brussels said that the bloc had not abandoned its position that any agreement on emissions cuts needed to be mandatory.

“Legally binding mitigation targets are definitely something that the EU is pushing for,” the official said. “This is one of our key asks. We’re yet to be convinced that you could have a sufficient rules-base and certitude by alternative approaches. But it is no secret that some other countries are in a different place.”

“The current agreement prototype includes options within options, and has a broad range of views of what constitutes legal force,” the source said. “We need to see Lima bring about more convergence, more focus to the text and allow zooming into the really big political crunch issues, as time is short.”

Claims by major countries that they could not impose economy wide targets were “disingenuous” and liable to stall the negotiating process over how commitments should be differentiated between developed and developing countries, the official added.

The comments came as French president François Hollande said on Thursday that the Paris summit had a “duty to succeed.” He said: “I have been asked when I became an environmentalist” and the answer was “when I arrived in power.”

“Because, at some point you have to leave your mark, and the mark we will leave together is a historic climate agreement…”

The US says it wants to put a ‘buffet option’ on the table in Lima, building on a New Zealand proposal that would contain some legally binding elements but allow countries to determine the scale and pace of their emissions reductions, even if this calls into question the aim of keeping temperature rises below 2C, the level that countries have agreed to limit warming to.

In Brussels earlier this month, the US special envoy on climate change, Todd Stern told journalists that while negotiations on the issue were ongoing, a ‘hybrid approach’ to legal enforcement offered the best chance of striking a deal agreeable to all.

“Proposals that would involve, in effect, a kind of designated burden-sharing on how reductions should be split up among countries of the world has extremely little chance of political viability,” he said. “Countries are not going to buy into that.”

Stern confirmed that a footnote to the US submission at a climate summit in Copenhagen in 2009 offered a 42% CO2 reduction by 2030 – higher than the 30% cut by 2025 announced by president Obama in China this month – but added that an 83% decrease by 2050 remained Washington’s objective in both cases.

The EU has gone further, setting out a stall for a legally binding 40% drop in emissions by 2030, but measures this against carbon output in 1990, rather than the US’s preferred 2005 baseline.

How to account for emissions commitments and monitor, report and verify (MRV) their implementation has taken on a correspondingly greater import.

“MRV provisions and accounting rules will be a core demand for the new agreement,” the EU official said. “Unless you have that, it will be difficult to validate that our partners are delivering on their commitments, so we need to really work with partners to ensure that we can come back on a regular basis and review our aggregated effort.”

While accepting that a binding deal could easily become a campaigning issue in the next US elections, the official said that Republicans could be persuaded to accept climate science if shown that a low carbon transition was possible.

Arthur Nelsen 

This article first appeared in the Guardian

edie is part of the Guardian Environment Network

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie