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The IPCC Ultimatum: Can renewable energy be scaled up in time?

The warnings contained in the IPCC’s latest synthesis report are stark. We ask Francis X Johnson, a senior research fellow at the Stockholm Environment Institute (SEI) who worked on the report, and Johannes Lehken, Head of Public Affairs (Europe) at Neste, what role renewables can play.

Nick van Mead

Nick van Mead


“We must move at warp speed,” warned UN secretary-general António Guterres at the launch of the Intergovernmental Panel on Climate Change’s (IPCC) AR6 Synthesis Report: Climate Change 2023 in Interlaken, Switzerland. “We don’t have a moment to lose. We must super-charge our efforts. The climate time-bomb is ticking.”

The synthesis report – the final stage in a seven-year cycle – painted a stark picture of humanity’s predicament: global surface temperatures are rising faster than any period for 2,000 years, atmospheric CO2 concentrations are higher than they have been for two million years, and more than 3.3 billion people are “highly vulnerable” to climate change. 

Deep global cuts in GHG emissions are required if we are to meet the target of limiting global temperatures to 1.5C, or even 2C, above pre-industrial levels – yet they continue to rise. Eighteen countries – including the US, France, Finland, Italy, the UK and Germany – have sustained greenhouse gas (GHG) emission reductions for more than a decade.  But that was more than offset by rising global activity levels in industry, energy supply, transport, agriculture and buildings. 

“Humanity is on thin ice,” as Guterres warned, “and that ice is melting fast.” 

Can renewables be scaled up in time?

“The price of procrastination”

Francis X Johnson, a senior research fellow at the Stockholm Environment Institute (SEI), worked on the IPCC synthesis report as a member of the extended writing team, helping to draw together its summary of three working group reports and three special reports on 1.5C, land and oceans.

“The average reader may be surprised there isn’t more about renewable energy,” he says, “but this is simply because of the breadth of the material. There are no new references, but the synthesis report contains around 66,000 references from previous reports. That’s an enormous amount of material to cover – everything relevant to climate change.”

Johnson says that population growth and other factors such as the consequences of wide-spread meat eating mean renewable energy alone is never going to be enough.

“It is a necessary condition that renewable energy is scaled up in a significant way – but it’s nowhere near sufficient if we’re going to meet the 1.5C target as emissions reductions are needed across all sectors and all systems,” he says. Johannes Lehken, Head of Public Affairs (Europe) at Neste, a global leader in the field of renewable diesel and sustainable aviation fuel, agrees. “That is the price of procrastination,” he says. “Renewables are not the silver bullet – it’s way too late for that."  

Rapid changes possible

Johnson, though, does see some good news in the report, including those 18 countries that managed to cut emissions and lower relative prices of solar and wind compared to fossil energy.

“Twenty or thirty years ago there was still an economic cost barrier to renewable energy,” he says, “but now that has gone. There remain other costs – such as financing, institutional capacity, the ability to absorb intermittent renewable energy into the grid and storage issues – that are easier to solve in richer countries. The economic cost is taken care of – at least for solar and wind, and getting closer for batteries – but there are other costs involved in scaling up to the whole world.”

Lehken also sees some positives: the progress of low-carbon technologies, greater commitments by governments (although they still need to follow through, he points out), and initiatives such as the European Union’s Fit for 55 programme and US president Joe Biden’s . Even global challenges such as the Ukraine war and the energy price crisis showed that a fast shift to alternative energy supplies was possible, he says, and now this momentum needs to be funneled towards renewables. 

Sustainable aviation fuel becoming the new normal

As well as solar and wind power, Johnson sees sustainable biofuels playing “a very important” role in reducing emissions in aviation, shipping and heavy road transport – but he warns that high demand in wealthy countries must be tackled too. 

"Extremely high levels of demand are the problem," says Johnson, who urges governments and policymakers to invest more in public transport, encourage walking and cycling, and move to densify cities so they become more efficient in terms of carbon use. "If you think you can avoid reducing demand in wealthy countries, then no, it likely won’t be possible to meet the targets. It’s hard to reduce demand – but without reducing demand it just gets more challenging."

For Lehken, too, liquid renewable fuels are part of the solution. “We as Neste welcome the drive towards electrification,” he says. “But trucks and other vehicles will be on the road using liquid fuel for a long time to come. It’s the same with aviation, changing to a non-liquid fuel will take decades and involve innovation across technologies, so for the foreseeable future it’s all about sustainable aviation fuel (SAF).” 

Draft legislation such as Europe’s  – which, as it currently stands, will mandate minimum levels of SAFs, from 2% in 2025 to 5% in 2030 and 63% in 2050 – will be a major boost, he says. “At the moment we are in an early stage, but SAF will be the new normal in the near future. It’s exciting to see this new industry emerging.

No time for delay

Another headline from the IPCC report was the importance of carbon removal to minimize global heating. “You can’t put all your eggs in one basket,” explains Johnson. “We can’t only focus on moving from fossil fuels to renewable energy. Carbon removal will be more and more necessary.”

So, can we do it? “The report shows it will be difficult to stay below 1.5C,” says Johnson. “2C seems more feasible. But to do that CO2 cuts need to be faster, deeper and across more sectors. CO2 stays around for a long time - you can’t delay cuts in carbon for 10 or 20 years.”

He concludes by emphasizing the importance of every emissions reduction we can make. "The impact of climate change gets more and more serious with each fraction of extra heating – and not just more serious, but more unpredictable. Every fraction of a degree matters.”


Nick van Mead, an award-winning city journalist with more than 20 years at the Guardian and the Associated Press, most recently as deputy editor of Guardian Cities.