A new study has revealed that without fully implementing legally binding and well-planned net-zero policies, it is likely that global climate goals set out in the Paris Agreement will be missed.
The new study, led by Imperial College London, has ranked 90% of net-zero greenhouse emissions targets as providing low confidence in their full implementation.
It was recommended that nations make their climate targets legally binding and well-planned with short-term implementation policies. This will increase the likelihood of avoiding the worst impacts of climate change.
Lead researcher Professor Joeri Rogelj, director of research for the Grantham Institute at Imperial, said: “Climate policy is moving from setting ambitious targets to implementing them. However, our analysis shows most countries do not provide high confidence that they will deliver on their commitments. The world is still on a high-risk climate track, and we are far from delivering a safe climate future.”
The team assigned a confidence assessment to each net-zero policy
The Paris Agreement goals limit global warming to well below 2°C and aim to keep temperatures below 1.5°C.
To achieve this, it is important to reach net zero greenhouse gas emissions as soon as possible. This is where emissions are offset.
Most countries have set net-zero targets and Nationally Determined Contributions. NDCs are non-binding plans proposing climate actions.
If fully implemented, there is a chance the world can keep warming to 1.5-2⁰C.
However, with current policies only and no implementation of net-zero pledges, models are predicting temperature rises could be as much as 2.5-3⁰C by 2100.
To reduce the uncertainty in which of these scenarios is likely to happen, the international team of researchers assigned a confidence rating to each net-zero policy.
The team assessed 35 net zero targets, covering every country with more than 0.1% of current global greenhouse gas emissions.
The confidence assessment was based on three policy characteristics:
- If the policy was legally binding;
- If there was a credible policy plan guiding implantation; and
- Whether short-term plans would put emissions on a downward path over the next decade.
Based on the assessment, policies were rated with ‘higher’, ‘lower’, or ‘much lower’ confidence of being fully implemented.
High-scoring regions included the EU, the UK, and New Zealand.
However, around 90% scored ‘lower’ or ‘much lower’ confidence. This included China and the US, which together account for more than 35% of current emissions.
The team modelled five scenarios of future greenhouse gas emissions
From the assessment, the team modelled five scenarios of future emissions and resulting temperatures.
The models were:
- Only current policies;
- Only adding in policies that have a high confidence of being implemented;
- Adding policies with high and low confidence;
- Adding all policies regardless of confidence if they were implemented; and
- All policies are fully implemented and all NDCs are met.
The first scenario, where only current policies are considered, had the largest uncertainty, with a range of 1.7-3°C and a median estimate of 2.6°C.
The most optimistic scenario has a range of 1.6-2.1°C, with a median estimate of 1.7°C.
This shows that if all net-zero policies are fully implemented, the Paris Agreement goals could be within reach.
However, as so many policies are ranked low-confidence, this could be wishful thinking in the absence of further efforts.
Co-author Taryn Fransen, from the World Resources Institute in Washington DC, and the Energy and Resources Group at the University of California–Berkeley, said: “Climate change targets are by their nature ambitious – there’s no point in setting a target for a foregone conclusion. But implementation must follow.”
Only 12 out of 35 net-zero policies are legally binding
Increasing the number of legally binding climate policies would help ensure the targets survive long-term and catalyse action.
The researchers believe countries need clear implementation pathways for different sectors, outlining exactly what changes are needed and where the responsibility lies.
Co-author Dr Robin Lamboll, from the Centre for Environmental Policy at Imperial, said: “Making targets legally binding is crucial to ensure long-term plans are adopted. We need to see concrete legislation to trust that action will follow from promises.”
