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Upward estimates for carbon budgets are unlikely to lead to action-focused climate policy. Climate researchers need to understand processes and incentives in policymaking and politics to communicate effectively.

Rapid emissions reductions, including reductions in deforestation-based land emissions, are the dominant source of global climate mitigation potential in the coming decades. However, carbon dioxide removal (CDR) will also have an important role to play. Despite this, it remains unclear whether current national proposals for CDR align with temperature targets. Here we show the ‘CDR gap’, that is, CDR efforts proposed by countries fall short of those in integrated assessment model scenarios that limit warming to 1.5 °C. However, the most ambitious proposals for CDR are close to levels in a low-energy demand scenario with the most-limited CDR scaling and aggressive near-term emissions reductions. Further, we observe that many countries propose to expand land-based removals, but none yet commit to substantively scaling novel methods such as bioenergy carbon capture and storage, biochar or direct air carbon capture and storage. Carbon dioxide removals (CDR) have been integrated into country-submitted reports under the Paris Agreement. However, this Analysis finds a gap between levels of CDR in these national proposals and the scenarios limiting global warming to the 1.5 °C target.

To limit warming, action plans from countries and companies must be fair, rigorous and transparent. To limit warming, action plans from countries and companies must be fair, rigorous and transparent.

Responses to the COVID-19 emergency have exposed break-points at the interface of science, media, and policy. We summarize five lessons that should be heeded if climate change ever enters a state of emergency perceived to warrant stratospheric aerosol injection.

As global negotiations fail on emissions reductions, scientific advisers need to resist pressure to fit the facts to the failure, warns Oliver Geden.

Current emission scenarios that allow keeping the global temperature increase below 2 °C or even 1.5 °C—as foreseen by the Paris Agreement—are based on very optimistic assumptions, including enormous volumes of carbon dioxide removal (CDR). A closer look at the globally most important emission sectors—power, transport and industry—shows manifold barriers for very ambitious mitigation. A new policy guideline called “Net Zero CO2 Emissions without relying on massive CDR” and promotion of technological research, in addition to economic incentives and other policy measures, would help to overcome the often simplistic demands for positive modelling results and refocus climate policy on tackling the enormous barriers in key emitting sectors. Such an approach is more aligned with the Paris Agreement’s bottom-up logic and therefore more appropriate to make the transformational project of global decarbonization a success.

Disenchantment has set in well ahead of the 21st Conference of the Parties (COP21) to the United Nations Framework Convention on Climate Change (UNFCCC) in Paris in December. Scientists, policy-makers and the public already accept that progress will not be enough to keep global average temperature rise within the 2 °C limit set at the 2010 UN climate summit.

Achieving the long-term temperature goal of the Paris Agreement relies on every actor maximising their effort to reduce emissions. Generic targets claiming a basis in science have been used to justify inequitable efforts that insufficiently stretch the ambition of the best-resourced countries and companies.

The Paris Agreement introduced three mitigation targets. In the future, the main focus should not be on temperature targets such as 2 or 1.5 °C, but on the target with the greatest potential to effectively guide policy: net zero emissions.

The 6th Assessment Report from the Intergovernmental Panel on Climate Change lacked sufficient land-sector scenario information to estimate total carbon dioxide removal deployment. Here, using a dataset of land-based carbon dioxide removal based on the scenarios assessed by the Intergovernmental Panel on Climate Change, we show that removals via afforestation and reforestation play a critical near-term role in mitigation, accounting for around 10% (median) of the net greenhouse gas emission reductions between 2020 and 2030 in scenarios that limit warming to 1.5 °C with limited overshoot. Novel carbon dioxide removal technologies such as direct air carbon capture and storage scale to multi-gigatonne levels by 2050 and beyond to balance residual emissions and draw down warming. We show that reducing fossil fuel and deforestation emissions (gross emissions) accounts for over 80% of net greenhouse gas reductions until global net zero carbon dioxide (CO 2 ) independent of climate objective stringency. We explore the regional distributions of gross emissions and total carbon dioxide removal in cost-effective mitigation pathways and highlight the importance of incorporating fairness and broader sustainability considerations in future assessments of mitigation pathways with carbon dioxide removal.