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Comprehensive policy measures are needed to close the emissions gap between Nationally Determined Contributions and emissions goals of the Paris Agreement. Here the authors present a Bridge scenario that may aid in closing the emissions gap by 2030.

This study analyses the consequences on mitigation pathways and economic efficiency of a separation for CO₂ and removal targets to achieve global net-zero CO2 emissions and finds that the economic efficiency losses of such separation are limited.

To evaluate the effectiveness of current national policies in achieving global temperature targets is important but a systematic multi-model evaluation is still lacking. Here the authors identified a reduction of 3.5 GtCO₂ eq of current national policies relative to a baseline scenario without climate policies by 2030 due to the increasing low carbon share of final energy and the improving final energy intensity.

Climate change and economic inequality are critical issues, and we still lack understanding of the interaction between them. Multi-model analysis shows how climate policies compatible with the goals of the Paris Agreement, including revenue-redistribution schemes, can reduce inequality—particularly in the short and medium terms.

A model shows how climate targets could be met by 2030 through a politically feasible mix of carbon pricing, low-carbon technology, and energy policy.

Ambitious climate policies can negatively impact the global poor by affecting income, food and energy prices. Here, the authors quantify this effect, and show that it can be compensated by national redistribution of the carbon pricing revenues in combination with international climate finance.

This analysis of net-zero strategies designed in an iterative stakeholder dialogue finds that without behavioral change and with restriction of technologies, the target of greenhouse gas neutrality in the European Union cannot be reached.

The Paris Agreement requires reaching net-zero carbon emissions, but a debate exists on how fast this can be achieved. This study establishes scenarios with different feasibility constraints and finds that the institutional dimension plays a key role for determining the feasible peak temperature.

The scale and nature of energy investments under diverging technology and policy futures is of great importance to decision makers. Here, a multi-model study projects investment needs under countries’ nationally determined contributions and in pathways consistent with achieving the 2 °C and 1.5 °C targets as well as certain SDGs.

Bioenergy has been widely viewed as an alternative for fossil fuels and an option for carbon dioxide removal, but there are doubts given the induced land-use changes. This study shows the importance of uniform regulation and comprehensive coverage of carbon-rich areas in reducing total emissions.

Under current land-use regulation, carbon dioxide emissions from biofuel production exceed those from fossil diesel combustion. Therefore, international agreements need to ensure the effective and globally comprehensive protection of natural land before modern bioenergy can effectively contribute to achieving carbon neutrality.

Current emissions scenarios include pathways that overshoot the temperature goals set out in the Paris Agreement and rely on future net negative emissions. Limiting overshoot would require near-term investment but would result in longer-term economic benefit.

The impact of rapidly falling costs of renewable energy and battery technology on long-term climate stabilization pathways is not well understood. Luderer et al. show that reduced renewable costs and climate policies will make electricity the cheapest energy carrier and can lead to electricity accounting for nearly two-thirds of global energy use by mid-century.

Current action is insufficient to meet both the Paris Agreement and the Sustainable Development Goals. Integrated model-based analysis shows that strong interventions across many dimensions, together with ambitious lifestyle change, are needed to enable real progress towards the UN Agenda 2030.

Many trajectories for reaching climate change mitigation targets exaggerate the long-term need for CO₂ removal (CDR) because they assume an exponentially increasing carbon price. Here the authors analyse alternative carbon price pathways that halt warming while limiting CDR, and may be easier to implement.

An integrated assessment model analysis shows that a moderately differentiated carbon price could achieve as much climate mitigation as a uniform carbon tax, avoiding concerns regarding equity between participating countries or sovereignty.

Residual CO₂ emissions from fossil fuels limit the likelihood of meeting the goals of the Paris Agreement. A sector-level assessment of residual emissions using an ensemble of IAMs indicates that 640–950 GtCO₂ removal will be required to constrain warming to 1.5 °C.

Scenarios that constrain end-of-century radiative forcing to 1.9 W m^–2, and thus global mean temperature increases to below 1.5 °C, are explored. Effective scenarios reduce energy use, deploy CO₂ removal measures, and shift to non-emitting energy sources.

Climate change mitigation scenarios are finding a wider set of users, including companies and financial institutions. Increased collaboration between scenario producers and these new communities will be mutually beneficial, educating companies and investors on climate risks while grounding climate science in real-world needs.

Scenarios have supported assessments of the IPCC for decades. A new scenario ensemble and a suite of visualization and analysis tools is now made available alongside the IPCC 1.5 °C Special Report to improve transparency and re-use of scenario data across research communities.

Mitigation scenario ensembles are becoming an important tool to bring new and robust insights into the transition to net zero. This Perspective unpacks their potential and identifies key steps for better use of scenario ensembles and to foster good practices.

The SSP–RCP scenario framework has been an important component of physical, social and integrated climate change research for the past decade. This Perspective reviews the successes of the framework and the challenges it faces, and provides suggestions for improvement moving forward.

A method of tracking changes in estimates of the remaining carbon budget over time should help to reconcile differences between these estimates and clarify their usefulness for setting emission reduction targets.

Scenario analyses suggest that negative emissions technologies (NETs) are necessary to limit dangerous warming. Here the authors assess the biophysical limits to, and economic costs of, the widespread application of NETs.

Experts using integrated assessment models to analyse the effects of climate change policy, have recently engaged in model inter-comparison projects (MIPs) to generate conclusions robust to different models' specifications. This Review synthesises results from the most comprehensive MIP that focuses on the different possible outcomes of post-2020 climate negotiations, recently announced pledges and their relation to the 2°C target.

A new analysis shows that global warming could be limited to 1.5 °C by 2100, but that the window for achieving this is small and rapidly closing.