The Paris agreement has failed: why net zero cannot stop climate breakdown

Record-breaking fossil-fuel output, unprecedented greenhouse-gas emissions and extreme heat are now commonplace. Yet, like the proverbial frog in a pan of warming water, we are failing to meet the climate and ecological crisis with anything resembling urgency.

In these conditions, assertions that global warming can still be held to no more than 1.5°C seem surreal.

Consider the opening of the 2023 international climate talks in Dubai. Sultan Al Jaber, the conference president, declared that 1.5°C was his objective and said his presidency would be driven by a "deep sense of urgency" to keep global temperatures at 1.5°C. At the same time, as chief executive of the Abu Dhabi National Oil Company, he was preparing a huge expansion of oil and gas production.

Such conduct may be unsurprising from the leader of a fossil-fuel corporation, but Al Jaber is far from exceptional.

Look beneath almost any net-zero commitment or policy presented as consistent with the 1.5°C aim of the landmark 2015 Paris agreement, and the same logic appears. It claims dangerous climate change can be avoided without undertaking what is actually required: rapidly cutting greenhouse-gas emissions from industry, transport, energy, which accounts for 70% of the total, and food systems, responsible for 30% of the total, while greatly improving energy efficiency.

Amazon offers a particularly revealing case.

In 2019, the company adopted a 2040 net-zero goal, subsequently verified by the UN Science Based Targets initiative (SBTi), which has spearheaded efforts to persuade companies to set climate targets compatible with the Paris agreement. Yet Amazon's emissions rose by 40% over the following four years.

After this poor record, the SBTi had to respond, removing Amazon and more than 200 other companies from its Corporate Net Zero Standard.

Nor is this unexpected. Net zero, and even the Paris agreement itself, were constructed around the assumed need to continue burning fossil fuels, at least in the near term. Ending this would be seen as a threat to economic growth, since fossil fuels still provide more than 80% of global energy overall.

The trillions of dollars in fossil-fuel assets that rapid decarbonisation would place at risk have likewise been a formidable obstacle to climate action.

Overshoot

The contradiction of claiming we can avert dangerous climate change while carrying on burning fossil fuels is best understood through the idea of overshoot. It promises that temperatures can rise beyond any threshold before planetary-scale carbon-dioxide removal pulls them down again by the end of the century.

This approach not only undermines efforts to keep warming to 1.5°C, but also risks catastrophic climate change by committing us to energy- and material-intensive measures that, for the most part, exist only on paper.

To maintain that safely exceeding 1.5°C, or any warming threshold, is possible is to say the quiet part aloud: the growing suffering and deaths caused while a recovery is pursued simply do not matter.

Carbon-dioxide removal is central to overshoot. In effect, it is presented as a time machine: decades of delay can supposedly be reversed by extracting carbon dioxide directly from the atmosphere.

We are told rapid decarbonisation is unnecessary today because future technologies will remove today's emissions. If that fails, we are invited to believe even more extravagant geoengineering schemes will rescue us, such as releasing sulphurous compounds into the upper atmosphere to block sunlight - a form of planetary refrigeration.

The 2015 Paris agreement was a remarkable achievement. Establishing 1.5°C as the internationally agreed upper limit for warming was a victory for communities and countries most vulnerable to climate hazards. Every fraction of a degree matters.

At the time, however, confidence that warming could genuinely be kept well below 2°C required faith that governments and businesses would commit themselves fully to decarbonisation. Instead, the Paris net-zero framework is drifting away from reality, increasingly dependent on speculative technology at science-fiction scale.

There is arguably an even more fundamental flaw in the Paris agreement. By defining climate change through temperature, it concentrates on the symptom rather than the cause.

Warming of 1.5°C, or any other level, results from humanity altering the climate's energy balance by raising atmospheric carbon-dioxide concentrations. This retains additional heat. The change in global average temperature is the established measure of that heat gain, but nobody lives through a global average.

Climate change becomes dangerous through weather affecting particular places at particular moments. Put simply, the extra heat is destabilising weather.

Temperature goals also make solar geoengineering appear sensible because it might reduce temperatures. Yet it would do so by increasing, rather than reducing, human interference with the climate system. Attempting to block the sun in response to growing carbon emissions is like switching on air conditioning during a house fire.

In 2021, we argued that net zero was a dangerous trap. Three years later, its jaws are visibly beginning to close, as climate policy is increasingly framed around overshoot. The effects on food and water security, poverty, human health, biodiversity and ecosystems will create intolerable suffering.

This moment requires honesty and a different direction. Without them, conditions are likely to worsen, perhaps quickly and in ways that cannot be controlled.

Farewell to the Paris agreement

It is time to accept that climate policy has failed and that the landmark 2015 Paris agreement is dead. We allowed it to die by pretending we could continue burning fossil fuels while also avoiding dangerous climate change.

Instead of calling for an immediate fossil-fuel phase-out, the Paris agreement set temperature targets for the 22nd century that could supposedly be achieved by balancing carbon sources and sinks.

Net zero thrived within this ambiguity. Apart from the economic shock caused by COVID in 2020, emissions have increased every year since 2015, reaching a record high in 2023.

Although extensive evidence shows climate action makes sound economic sense - the cost of inaction is vastly greater than the cost of action - no country strengthened its pledges at the past three COPs, the annual UN international meetings. This was despite it being clear that the world was on course to pass 2°C, let alone 1.5°C.

The Paris agreement ought to deliver a 50% cut in greenhouse-gas emissions by 2030, but existing policies put emissions on track to exceed their present level.

We do not dispute the substantial advances in renewable technologies. Wind and solar deployment has risen every year for the past 22 years, while carbon emissions have fallen in some of the wealthiest countries, including the UK and the US.

But the pace remains inadequate.

A core principle of the Paris agreement is that wealthier countries must lead decarbonisation, allowing lower-income countries more time to move away from fossil fuels. Contrary to some assertions, the global energy transition is not in full swing.

Indeed, it has not truly started, because a transition requires a reduction in fossil-fuel consumption. Instead, that consumption continues to rise year after year.

Policymakers are therefore turning to overshoot to claim they possess a strategy for avoiding dangerous climate change. A central assumption behind that strategy is that the future climate system will continue operating as it does now.

That assumption is reckless.

2023's warning signs

At the beginning of 2023, Berkeley Earth, NASA, the UK Met Office and Carbon Brief forecast that the year would be marginally warmer than the preceding one but unlikely to break records. Twelve months later, all four organisations concluded that 2023 had been, by a substantial margin, the warmest year ever recorded.

Indeed, from February 2023 to February 2024, warming in global average temperature exceeded the Paris target of 1.5°C.

The extreme weather of 2023 offers a preview of the suffering additional warming will bring. A 2024 World Economic Forum report found that, by 2050, climate change may have caused more than 14 million deaths and US$12.5 trillion in loss and damages.

We cannot yet completely account for the exceptionally high global temperatures of the past 18 months. Shifts in dust, soot and other aerosols matter, while natural processes including El Niño will also be influencing events.

But something appears still to be missing from our understanding of how the climate is reacting to human pressures. This includes alterations to the Earth's essential natural carbon cycle.

Roughly half of all carbon dioxide humanity has released into the atmosphere throughout its history has entered land and ocean "carbon sinks". This removal comes "for free", and without it warming would be considerably higher.

Carbon dioxide in the air dissolves into the oceans, making them more acidic and threatening marine ecosystems. Meanwhile, higher carbon-dioxide levels encourage plants and trees to grow, storing carbon in leaves, roots and trunks.

Every climate policy and scenario assumes these natural carbon sinks will go on removing tens of billions of tonnes of carbon from the atmosphere annually.

Evidence suggests land-based sinks, including forests, absorbed significantly less carbon in 2023. Should natural sinks start to fail - as they may in a warmer world - reducing global temperatures will become harder still.

The only credible means of limiting warming to any level is to stop releasing greenhouse gases into the atmosphere in the first place.

Science-fiction solutions

It is evident that the commitments countries have made under the Paris agreement cannot keep humanity safe while emissions and temperatures continue setting records.

Proposals to spend trillions of dollars this century on extracting carbon dioxide from the air, or on countless other methods for manipulating the climate, amount to an admission that the world's biggest polluters will not curb fossil-fuel burning.

Direct Air Capture (DAC), Bio Energy Carbon Capture and Storage (BECCS), enhanced ocean alkalinity, biochar, sulphate aerosol injection and cirrus cloud thinning - this entire wacky race of carbon-dioxide removal and geoengineering only makes sense in a world where climate policy has failed.

Climate impacts will intensify in the years ahead.

Deadly heatwaves will occur more frequently. Storms and floods will become ever more destructive. More people will be forced from their homes. National and regional harvests will collapse.

Enormous sums will be required for climate adaptation, and perhaps even greater sums to compensate those worst affected. We are expected to accept that, while all this unfolds and more besides, new technologies that directly alter the Earth's atmosphere and energy balance will be deployed successfully.

Moreover, some of these technologies might have to operate for three hundred years to prevent the consequences of overshoot. Rather than swiftly slowing carbon-polluting activity and improving the odds of Earth-system recovery, we are committing ourselves to net zero and overshoot in an increasingly desperate belief that untested science-fiction solutions will save us from climate breakdown.

The cliff edge is visibly approaching. Yet rather than applying the brakes, some are pressing harder on the accelerator. They justify this madness by arguing that greater speed is needed to make the leap and land safely beyond it.

We believe many advocates of carbon-dioxide removal and geoengineering act in good faith. But their proposals include refreezing the Arctic by pumping seawater onto ice sheets to create fresh layers of ice and snow. These ideas may be worth researching, but there is very little evidence that they would affect the Arctic, much less the global climate.

These are the intellectual knots people create when they recognise climate policy's failure but refuse to challenge the underlying forces producing it. Inadvertently, they are slowing the only effective response: rapidly phasing out fossil fuels.

This is because atmospheric carbon-removal and climate-geoengineering proposals promise recovery from overshoot through innovation driven by growth. Their analysis ignores the fact that this growth is powered by the same fossil fuels causing the crisis.

The essential point is that the climate system is utterly indifferent to our pledges and promises.

It is unconcerned with economic growth. If fossil-fuel burning continues, the climate will not stop changing until the energy balance is restored. By then, millions of people may be dead and many more may face intolerable suffering.

Major climate tipping points

Even if carbon-removal and geoengineering technologies could be deployed in time, the plan to exceed 1.5°C and lower temperatures later faces a profound problem: tipping points.

Tipping-point science is developing rapidly. Late last year, one of us (James Dyke), alongside more than 200 academics worldwide, contributed to the Global Tipping Points Report.

It reviewed the latest research on possible tipping points in the climate system and considered how social systems might change quickly, in the desired direction, to generate positive tipping points.

Across the report's 350 pages is extensive evidence that overshoot is an extraordinarily dangerous gamble with humanity's future. Some tipping points could cause global havoc.

Melting permafrost could release billions of tonnes of greenhouse gases into the atmosphere, intensifying human-caused climate change.

Fortunately, this appears unlikely at current warming levels. Unfortunately, the likelihood of a collapse in North Atlantic ocean currents may be far higher than previously believed.

Should this occur, weather systems worldwide, and especially in Europe and North America, would be thrown into chaos.

Beyond 1.5°C, warm-water coral reefs are moving towards annihilation. The latest science finds that, at 2°C, global reefs would be reduced by 99%. The devastating bleaching event now affecting the Great Barrier Reef follows several mass-mortality events. It is not enough to say we are watching one of the world's greatest biological wonders die.

We are knowingly killing it.

We may even have already crossed certain major climate tipping points.

Earth has two great ice sheets: Antarctica and Greenland. Climate change is causing both to disappear. From 2016 to 2020, the Greenland ice sheet lost an average of 372 billion tonnes of ice annually. The current best estimate for the Greenland ice sheet reaching a tipping point is about 1.5°C.

This does not mean the Greenland ice sheet would suddenly collapse if warming goes beyond that level. It contains so much ice - around 2,800 trillion tonnes - that complete melting would take centuries, during which sea level would rise by seven metres.

If global temperatures were lowered again after a tipping point, the ice sheet might be stabilised. But we cannot say with certainty that such recovery would be possible. As we wrestle with the science, Greenland is losing an average of 30 million tonnes of ice every hour.

The central lesson of research into these and other tipping points is that additional warming speeds our path to catastrophe. It is crucial science, but is anybody listening?

It's five minutes to midnight…again

We know climate action is urgent because we are repeatedly told time is running out. In 2015, Professor Jeffrey Sachs, UN special adviser and director of The Earth Institute, declared:

The time has finally arrived – we've been talking about these six months for many years but we're now here. This is certainly our generation's best chance to get on track.

In 2019, the then Prince Charles said in a speech: "I am firmly of the view that the next 18 months will decide our ability to keep climate change to survivable levels and to restore nature to the equilibrium we need for our survival."

"We have six months to save the planet," urged International Energy Agency head Fatih Birol one year later, in 2020. In April 2024, Simon Stiell, executive secretary of the United Nations Framework Convention on Climate Change, said the next two years are "essential in saving our planet".

Either the climate crisis possesses the fortunate quality of allowing the countdown to catastrophe to be reset indefinitely, or we are deceiving ourselves with unending claims that time has not quite expired. If you can keep pressing snooze on an alarm and go back to sleep, the alarm is not working.

There is another explanation. Emphasising that little time remains is meant to concentrate attention on climate negotiations. It forms part of a broader effort not only to awaken people to the impending crisis but also to create effective action. This is sometimes offered as an explanation for how the 1.5°C warming threshold was agreed.

Rather than a precise target, it is said to be a stretch goal. We may fail, but striving for it makes us move much faster than a higher target, such as 2°C, would. Consider this statement from 2018:

Stretching the goal to 1.5 degrees celsius isn't simply about speeding up. Rather, something else must happen and society needs to find another lever to pull on a global scale.

What might this lever be? Fresh economic thinking beyond GDP? Serious consideration of how wealthy industrialised countries could provide financial and material support enabling poorer nations to bypass fossil-fuel infrastructure? Participatory-democracy methods capable of fostering the radical new politics needed to restructure fossil-fuelled societies? None of these.

The proposed lever is Carbon Capture and Storage (CCS), because the quotation above came from a 2018 Shell article. In this advertorial, Shell argued that fossil fuels would be needed for many decades. CCS offers the promise that fossil fuels can keep being burned without carbon-dioxide pollution, by capturing the gas before it exits the chimney.

In 2018, Shell was promoting its Sky Scenario, heavily reliant on carbon removal and offsets. Leading climate-change academics called the approach "a dangerous fantasy" because it assumed huge carbon emissions could be offset through tree planting.

Since then, Shell has further funded carbon-removal research at UK universities, presumably to strengthen its case for continuing to extract vast quantities of oil and gas.

Shell is not alone in brandishing carbon-capture magic wands. Exxon is making major claims for CCS as a route to net-zero hydrogen from fossil gas. Academics have sharply criticised these claims, while recent reporting has exposed industry-wide CCS greenwashing.

But the problem runs far deeper. Every climate-policy scenario proposing to limit warming to close to 1.5°C depends on the largely unproven technologies of CCS and BECCS.

In theory, BECCS sounds attractive. Instead of burning coal in a power station, biomass such as wood chips is burned. If as many trees were grown as were cut down and burned, this would initially be a carbon-neutral means of producing electricity.

Adding scrubbers to power-station chimneys to capture the carbon dioxide, then burying it deep underground, would allow electricity generation while lowering atmospheric carbon-dioxide concentrations.

In practice, however, clear evidence now shows large-scale BECCS would severely harm biodiversity and food and water security because vast areas of land would be devoted to fast-growing monoculture tree plantations.

Burning biomass may even be increasing carbon-dioxide emissions. Drax, the UK's largest biomass power station, now emits four times as much carbon dioxide as the UK's largest coal-fired power station.

Five-minutes-to-midnight messages may genuinely seek to galvanise action, underline the situation's urgency and stress that there is still, just, time. But time for what? Climate policy offers only incremental change, and certainly nothing that could threaten economic growth or redistribute wealth and resources.

Despite increasing evidence that globalised industrial capitalism is driving humanity towards disaster, five minutes to midnight leaves no time or space to consider alternatives seriously. Instead, the offered solutions are technological fixes that preserve the status quo and insist fossil-fuel companies such as Shell must be part of the answer.

This is not to claim there are no good-faith arguments for 1.5°C. But good intentions do not change reality. The reality is that warming will soon exceed 1.5°C and the Paris agreement has failed.

In that context, continually urging people not to lose hope and insisting an unavoidable outcome can be avoided risks becoming counterproductive. If you demand the impossible - burning fossil fuels while preventing dangerous climate change - you must invoke miracles. A whole fossil-fuel industry is desperate to sell those miracles in the form of CCS.

Four suggestions

Humanity already has enough problems; what is needed are solutions.

This is sometimes the response when we argue that the net-zero concept and Paris agreement have fundamental flaws. It can be reduced to one straightforward question: so what's your suggestion?

We offer four below.

1. Leave fossil fuels in the ground

The inescapable reality is that fossil-fuel burning must stop rapidly. The only certain way to achieve that is to keep fuels in the ground. We must end exploration for new reserves and stop exploiting existing ones. Ending fossil-fuel finance could achieve this.

At the same time, the food system must be transformed, particularly livestock production, which produces nearly two thirds of agricultural emissions. Begin there, then decide how economies' goods and services can best be distributed. Let those arguments be grounded in reality rather than wishful thinking.

2. Ditch net-zero crystal-ball targets

The entire framework of net-zero goals for the middle and end of the century should be discarded. We are already in the danger zone. What is required is immediate action, not promises to balance carbon budgets decades from now. The SBTi should concentrate on near-term emissions cuts. By 2030, global emissions must be half their current level for there to be any prospect of keeping warming to no more than 2°C.

Those with the greatest power - politicians and business leaders - are responsible for acting now. We must therefore demand twin targets: every net-zero plan should contain a distinct goal for real reductions in greenhouse-gas emissions. Inaction must no longer be concealed behind promised future removals. Our children and future generations will be left to repay the overshoot debt.

3. Base policy on credible science and engineering

Climate policy must rest on what can be accomplished in the real world today or in the very near future. Only where a proposed method has been shown to remove a credible quantity of carbon - including capture and secure permanent storage - should it be included in net-zero plans. The same principle applies to solar geoengineering.

Speculative technologies should be removed from every policy, pledge and scenario until we know how they will operate, be monitored, reported and validated, and affect not merely the climate but the Earth system as a whole. This would probably demand a very substantial expansion of research. As academics, we enjoy research. Yet academics must be cautious that the conclusion "needs more research" is not taken to mean "with a bit more funding this could work".

4. Get real

Across the world, thousands of groups, projects, initiatives and collectives are working for climate justice. But although there is a Climate Majority Project and a Climate Reality Project, there is no Climate Honesty Project, although People Get Real comes close. Extinction Rebellion formed in 2018, demanding governments tell the truth about the climate crisis and act accordingly. We can now see that politicians making net-zero promises were also crossing their fingers behind their backs.

We must acknowledge that net zero, and now overshoot, are being used to argue that nothing fundamental must change in energy-intensive societies. Honesty is required about our present situation and our direction of travel. Difficult truths must be spoken, including the immense inequalities in wealth, carbon emissions and vulnerability to climate change.

The time for action is now

Politicians are rightly blamed for their failure to act. Yet in some ways, we get the politicians we deserve. Most people, including many who care about climate change, still demand cheap food and energy alongside a constant flow of consumer goods.

Cutting demand merely by raising prices risks forcing people into food and energy poverty. Policies to lower consumption emissions must therefore extend beyond market-based measures. The cost-of-living crisis is inseparable from the climate and ecological crisis. Both require us to radically reconsider how economies and societies operate, and whose interests they serve.

Returning to the boiling-frog predicament introduced at the beginning, it is long past time to jump from the pot. We should ask why we did not do so decades ago.

Here, the analogy provides a useful insight into net zero and the Paris agreement. The familiar boiling-frog story omits an essential fact: ordinary frogs are not stupid. They may remain in gradually warming water, but once it becomes uncomfortable they try to escape.

The modern parable derives from late-19th-century experiments involving frogs that had been "pithed" - a metal rod was pushed into their skulls, destroying higher brain function. These radically lobotomised frogs would indeed remain motionless in water that was boiling them alive.

Net-zero promises and assurances of recovery from overshoot stop us struggling towards safety. They tell us that nothing too drastic is needed yet: be patient, relax. Meanwhile, the planet burns and every prospect of a sustainable future goes up in smoke.

Admitting the failures of climate-change policy does not mean surrendering. It means accepting the consequences of mistakes and refusing to repeat them. We must map routes towards safe and just futures from where we actually are, not from where we wish to be.

The time has come to leap.

James Dyke, Associate Professor in Earth System Science, University of Exeter; Robert Watson, Emeritus Professor in Environmental Sciences, University of East Anglia, and Wolfgang Knorr, Senior Research Scientist, Physical Geography and Ecosystem Science, Lund University

This article is republished from The Conversation under a Creative Commons license. Read the original article.