Net zero is an insidious loophole that distracts from the scientific imperative to eliminate fossil fuels | Joëlle Gergis

As world leaders gather this year in Brazil for Cop30 – the first Amazon Cop – it is worth a quick reality check on how we are collectively tracking the reduction of global greenhouse gas emissions.

Despite 30 years of UN climate summits, about half of the carbon dioxide accumulated in the atmosphere since the industrial revolution has been emitted since 1990. Incidentally, 1990 was the year that the Intergovernmental Panel on Climate Change – the world’s authority on the science of climate change – released its first assessment report confirming the threat of human-caused global warming. As scientists around the world prepare the IPCC’s Seventh Assessment Report, we do so knowing that our work is still overshadowed by politics. Despite all the well-intentioned half-measures, the truth is that the world is still far from being on track to limit dangerous climate change.

In the flurry of technical reports released ahead of Cop30, the World Meteorological Organization said CO₂ concentrations reached a record high of 423.9 parts per million in 2024, with the growth rate from 2023 to 2024 seeing the largest annual increase since modern measurements began in 1957. Latest figures from the Global Carbon Project show that 90% of total global CO₂ emissions in 2024 were generated by the burning of fossil fuels, with the remaining 10% coming from land-use changes including deforestation and wildfires.

While the growth of fossil CO₂ In 2024, fueled by rising gas and oil emissions – together accounting for just over half of global emissions – coal burning hit a record high, accounting for 41%. Despite Cop28’s global review calling on all nations to help “move away from fossil fuels”, there are still collective plans to produce more than double the amount of fossil fuels in 2030 than is consistent with limiting global warming to 1.5°C, with continued gas extraction rationalized as a lower emissions-intensive “transition fuel”.

Instead of focusing on economic incentives to encourage the rapid phase-out of fossil fuels, climate policies rely heavily on “nature-positive” solutions that aim to neutralize carbon emissions by essentially planting trees instead of reducing industrial emissions. While protecting, expanding and rehabilitating natural carbon sinks like forests and wetlands is a good thing in itself, researchers have shown that there is not enough land to reach the global goal of net zero emissions using nature-based solutions alone.

Around 1 billion hectares – an area larger than the United States of America – are needed to achieve net-zero emissions commitments. More than 40% of this land is expected to be converted from existing uses like food production to carbon sequestration projects by 2060 at an unprecedented rate.

And even if this regenerative utopia could be realized, we know that forests take time to mature and can burn and therefore cannot be considered a quick or permanent carbon storage solution, especially in a rapidly changing climate. As extreme heat and aridity engulf more of the planet, these well-intentioned efforts could literally go up in smoke.

Science tells us that about half of total CO₂ emitted each year remains in the atmosphere, while the remainder is absorbed by Earth’s oceans and terrestrial ecosystems. As the planet warms, these natural carbon sinks become less and less effective at absorbing CO.₂which means more carbon is accumulating in the atmosphere, further worsening global warming. Shifting the burden of mitigation to the land sector simply relieves the fossil fuel industry of pressure to reduce emissions in the near future.

Reaching net zero by 2050 requires carbon dioxide removal (CDR), which currently relies almost exclusively on land-based measures to absorb excess carbon from the atmosphere. Polluters can simply purchase carbon credits to offset their emissions and continue business as usual. Meanwhile, the energy imbalance caused by the burning of fossil fuels continues to further destabilize Earth’s climate. Essentially, we are adding more carbon debt to our planetary credit card, leaving future generations with an unpayable liability.

To limit the extent and duration of overshooting the Paris Agreement temperature targets, the world must ultimately move well beyond the neutralizing effect of net zero and begin reducing historical cumulative emissions to achieve “net negative emissions.”

According to the latest figures from the Global Carbon Project, vegetation-based CDR currently absorbs the equivalent of around 5% of annual fossil carbon dioxide emissions, while technology-based CDR only accounts for around a millionth of the CO2 emitted by fossil fuels. More generous industry estimates are around 0.1% of total global emissions. At the risk of sounding like a heretic, the political distortion of net zero is an insidious loophole that distracts from the scientific imperative to eliminate the primary cause of our planet’s overheating: fossil fuels.

Although this scientific reality is expected to dominate discussions at Cop30, history tells us that polite incrementalism and political kowtowing will prevail. Vague statements about future ambitions will continue to delay the urgent need for immediate concrete action. Until our leaders have the courage to put a price on carbon to end the fossil fuel era for good, we will add more and more carbon to the atmosphere, worsening the physical catastrophe currently unfolding all around us.

The dilemma we face is simple: truly respond to the scientific reality of our predicament or endure the consequences of this profound moral failure for centuries to come.