Fossil fuel emissions rise again - but renewables boom offers hope for climate

The world's burning of fossil fuels is set to release more planet-warming carbon dioxide than ever before this year, new figures show.

It is another sign that efforts to fight climate change by cutting emissions are moving far too slowly to meet international targets, as countries meet in Brazil for UN climate talks COP30.

But emissions have grown much less quickly over the past decade as renewables have taken off, providing hope that the world's warming trend can still be curbed.

And separate analysis by clean energy think tank Ember suggests that fossil fuel use in electricity generation has flatlined in 2025, largely thanks to the rapid growth of solar power.

It adds weight to the idea that global emissions may be nearing a peak – even though it's hard to say exactly when that might come.

Carbon dioxide (CO2) emissions for 2025 are of course an estimate, with the year not yet complete – but they show a mixed picture.

Emissions from fossil fuels and cement are forecast to increase yet again to 38.1bn tonnes of CO2, according to the Global Carbon Budget team, which comprises more than 130 scientists from 21 countries.

That would be up 1.1% on 2024.

Emissions from changing land-use – such as permanent deforestation – are forecast to be lower than last year, however.

That's largely due to the end of the natural El Niño weather pattern - which can drive higher forest losses – but is the continuation of a longer-term trend.

It means that, altogether, total emissions from all human activities are expected to reach 42.2bn tonnes CO2 in 2025 - down from the 42.4bn in 2024, albeit marginally.

What is clearer, the team say, is that emissions have grown more slowly over the past decade - 0.3% per year - compared to the previous decade's 1.9% per year.

And over the past 10 years, 35 countries significantly cut their fossil fuel emissions while also growing their economies, they say. That is nearly double the number in the decade before.

"We're not yet in a situation where the emissions go down [as] rapidly as they need to, to tackle climate change, but at the same time there are a lot of positive [developments]" said Corinne Le Quéré, professor of climate change science at the University of East Anglia.

Emissions have been growing much less rapidly than before "because of that extraordinary growth in renewable energy in China and elsewhere", she added.

Nearing peak?

This effect of the renewables boom is highlighted by emissions in the power or electricity sector.

Electricity generated from fossil fuels is forecast to flatline or even decline slightly this year, according to the think tank Ember, for the first time since the Covid-19 pandemic.

What's unusual about this year, Ember says, is that this has happened even though electricity demand increased sharply, rather than resulting from an economic recession.

And this year's extra electricity demand has been more than met by wind and, particularly, solar.

"We've had decades and centuries where fossil fuels were the only way that we could really grow our economy, and over the last decade, that's changed for the first time," said Nicolas Fulghum, senior data analyst at Ember.

"Solar power is growing at a record pace, and faster than any electricity source in history," he added.

What happens in the power sector is particularly important in the fight against climate change.

It is the single biggest emitting sector and is expected to play an increasing role in the energy system as more people buy electric cars, heat pumps and other technologies.

"Whatever happens in the power sector has an outsized influence on what happens for emissions worldwide," said Mr Fulghum.

Ember is confident that emissions from using fossil fuels to generate electricity are now plateauing and could begin a permanent decline in a few years.

That echoes yesterday's message from the International Energy Agency, the global energy watchdog.

Carbon emissions from energy systems – more than just electricity - could peak within the next few years, based on countries' stated policies, it said.

While there is still uncertainty about the exact timing of a peak, it would undoubtedly be a landmark moment in the fight against climate change.

It would not halt warming, however, as countries would still be adding CO2 to the atmosphere - just at a slower rate.

"As long as we emit CO2, the warming will continue… to stop further warming, we have to bring [net] emissions to zero," said Prof Pierre Friedlingstein, chair in mathematical modelling of climate systems at the University of Exeter.

And another analysis released today to coincide with COP30 offers a reality check.

The Climate Action Tracker research group finds that warming could reach 2.6C above pre-industrial levels by the end of the century based on current policies – a figure which has barely changed over the past few years.

"It's very clear that we have never had a better chance to do this. It's also clear that we've never been in a worse situation," said Dr Bill Hare, from the Climate Action Tracker team.

"So it's a diabolical dilemma. Things could go really badly. We could walk away from this COP without taking the right kind of action, and entrenching fossil gas and oil, and we'll push towards 2.5C [or] 3C warming for sure," he added.

"But on the other hand, the chance is there… to do exactly the opposite, and to build on the momentum of the technology changes going on globally."

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