For the first time since 2019 and following a flurry of net-zero pledges from the world's largest emitters, UN climate negotiations resume Monday in a virtual format just six months before the crunch COP26 summit.
The talks, nominally hosted by the United Nations climate change programme in the German city of Bonn, will all be informal, meaning that no decisions will be taken during the three-week dialogue.
But with increasingly dire warnings from scientists that the pace of global warming is already outstripping humanity's best plan to cut emissions, the pressure for progress to be made on a number of thorny issues is high.
In 2018, countries agreed to many elements of the Paris agreement "rulebook", governing how each nation implements its goals.
But several issues remain unresolved, including rules about transparency, carbon markets, and a unified timeframe for all countries to ratchet up their emissions cuts.
At the last UN climate summit in December 2019, countries also failed to agree upon a universal system of reporting climate finance.
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Nathan Cogswell, a research associate at the World Resources Institute, said a deal on greater transparency was "a central component of the effective implementation of the Paris agreement".
"The upcoming session will hopefully help parties get closer to that."
One of the thorniest debates during recent UN climate talks has been Article 6 of the Paris Agreement, which deals with the trade of emissions cuts.
A major sticking point remains over rules to avoid double counting emissions reductions within both bi-lateral and international carbon markets.
Some wealthy nations without the natural resources -- forests, for instance -- to mitigate their contribution to climate change have spent huge amounts on projects to preserve those habitats in other countries.
Currently both the buying and selling nations may count the project towards their domestic climate action, opening the door for the same cut to be counted twice.
Cogswell said that a failure to agree on a protection against double counting emissions reductions by the end of the COP26 in Glasgow in November would "weaken the ambition of global efforts" to fight climate change.
Covid-19 forced Britain and the UN to shelve talks originally scheduled for last year until the end of 2021.
As the pandemic continues to rage, particularly among developing nations most vulnerable to the impacts of climate change, negotiators will need to achieve tangible progress during the three-week Bonn talks.
"The absence of a COP left a tremendous amount of work to be done... if we want to deliver at Glasgow," said Marianne Karlsen, chair of a major technical forum at the UN-led negotiations.
The two-week sessions -- expanded this year to three -- normally involve thousands of representatives from more than 180 countries, and often rely on behind-closed-doors bargaining between delegates to get deals done.
Karlsen said the virtual configuration of talks was "not ideal at all".
"We really wanted to be able to have all the interactions of when we meet in person but there was no other option," she said.
Tosi Mpanu Mpanu, chair of the UN's SBSTA technical working group, said delegates needed to use the virtual negotiations to "prioritise a way to capture progress, so we can capture that progress when we meet in person, and make decisions" in Glasgow.
"It's important that we send a clear message to the world: We are very much engaged in resolving the Paris rulebook and to tackling this climate change conundrum."