Electrifying the world – with electric vehicles, electric heating and cooling, and modernised heavy industry – could be the next biggest step towards phasing out fossil fuels, replacing the 80% of global energy that still comes from hydrocarbons. As using electrical energy is much more efficient than combustion, the move would save billions of dollars for consumers and businesses – global energy demand could be halved, according to one estimate.

For decades, electrification has been a nerdish backwater of global climate action. But in the last two weeks, at preparatory talks in Bonn before the forthcoming UN Cop31 climate summit, the subject finally took centre stage.

Murat Kurum, Turkey’s environment minister, who will co-host the Cop31 summit this November, told the Guardian last week: “Without electrification, we won’t be able to reach any of the targets [of the Paris agreement], so we must go through this transformation. Whether you call it the missing piece of the puzzle or the most important tool that we have in our toolkit, this is the case.”

Turkey, with the support of Australia, which is co-president of Cop31, has proposed setting a target of 35% of final energy to come from electricity by 2035. “This is the most important pillar in reducing emissions – you need to increase electrification in cities, in manufacturing, in [all aspects of life], and will serve us in the bigger picture, the bigger targets [of the Paris agreement],” he said.

The push to electrify was the highlight of two weeks of talks in Bonn that otherwise offered little to cheer. After a cordial start to the annual meeting, held roughly at the halfway point between annual climate “conference of the party” (Cop) summits, by the final days the negotiations descended into near-farce, with some countries refusing to agree wording that would base decisions on “the best available science”, despite this being a cornerstone of climate agreements for more than 30 years. The talks, which were supposed to lay the groundwork for Cop31, finished on Thursday evening with many issues unresolved.

“We have seen side-stepping and stalling,” said the UN climate chief, Simon Stiell, admonishing countries as two weeks of talks slid to a conclusion on Thursday night. “We’ve seen geopolitical tensions wash through these halls. We simply cannot afford to reopen previous decisions, to renegotiate existing targets, or to backslide. It’s cooperation, not fierce competition, that we need.”

The biggest rows were over climate science, and the 1.5C goal. In a strand of the talks known as “research and systematic observations”, some countries – led by Saudi Arabia and the Arab group of nations, but also including India – objected to language reaffirming climate science, and argued that research by scientists in rich countries dominated submissions to the Intergovernmental Panel on Climate Change.

But other countries said the aim was clearly to delay and derail. Sivendra Michael, speaking on behalf of the Pacific Island nations, said: “We are hearing voices in these rooms that are doing their best to undermine science. Anyone blocking references to science, they are not our friends.”

He added: “There are powerful interests desperate to protect their wealth and influence. We are seeing certain countries holding the [UN] process hostage as vulnerable people suffer heat stress and storms, droughts and famine.”

There were also questions raised by many of the same countries over the inclusion of the global target of limiting temperatures to 1.5C in several places in the negotiating texts, but they faced furious opposition.

Surangel Whipps, the president of the Pacific nation of Palau, told a separate conference in Germany: “We know we won’t make the 1.5C target, but what we need to do is not give up.”

Greater harmony was on show over the “just transition”, a key issue for campaigners which refers to the need to ensure that workers affected by the move to a low-carbon economy are supported, and protected from exploitation.

Camila Mercure, the climate policy coordinator at Fundación Ambiente y Recursos Naturales, said the discussions had been constructive. “While [the talks] exposed significant differences among parties, they also showed there is a pathway to a meaningful outcome [on a just transition] at Cop31. Governments must now engage constructively to make that happen.”

But climate finance remains a huge stumbling block as developed countries continue to cut overseas aid and prioritise military spending. Poor countries were furious that rich nations were dragging their feet on fulfilling a previously set goal to triple the funding they provide for adaptation to the impacts of the climate crisis. Pooja Dave, the adaptation policy coordinator at Climate Action Network International, said: “What we saw was clear bad faith and unwillingness by developed countries to make progress on the global goal on adaptation. You cannot implement the GGA without finance.”

At last year’s Cop30 summit in Brazil, attempts to get countries to restate their commitment to “transition away from fossil fuels” were stymied, but more than 50 countries held their own conference in April to discuss such a phaseout.

But the electrification target marked a step change, after years with little mention at Cops, in part because the technology for electrification lagged behind that for renewable generation. But now China has moved to mass manufacture of electric vehicles, bringing prices down, while heat pumps have also come down in price, though less dramatically, and can save consumers hundreds of pounds on their energy bills. Industrial processes are also increasingly switching to cheap renewable energy.

Electric technology, according to Prof Jan Rosenow from Oxford University, is now ready for widespread takeup and offers efficiencies three to five times greater than their fossil fuel counterparts. “I call it electro-efficiency,” he said. “It’s the inbuilt efficiency of electric technology compared with fossil fuels.”

Rosenow has estimated, in a forthcoming paper, that a global switch to electrification would halve energy demand. That would produce savings that would quickly reach trillions of dollars globally, freeing up cash for governments, businesses and consumers to spend on better ends, from health and education to defence.

Some countries are way ahead. Japan, for instance, has nearly reached the target of 35% of energy to come from electricity that the Cop31 presidency is proposing. China is nearly at 30%, but the US lags at 22%, India and Brazil are about 20% and globally the figure is 21%.

But even the Cop measures on electrification, though widely accepted as necessary to meet scientific advice to reduce emissions to net zero by mid-century, face an uphill struggle to gain acceptance within the byzantine processes of the Cop.

While the US is the only major country absent from the UN talks, the influence of Donald Trump’s presidency was felt within the negotiating halls. “Saudi Arabia has taken more of an obvious role [in disrupting progress], and part of that is because the US used to play a role in holding them back,” one negotiator said. Saudi is not alone: it has allies among the Gulf states, which work together as the Arab group, and has been joined by India on some issues, Russia on several, and even by Kenya, usually a strong supporter of climate action. “People feel they can do this because of what they see coming from the US now,” the negotiator said.