Emissions Pathways

Current policies in place around the world are projected to result in about 2.6°C¹ warming above pre-industrial levels. 2030 and 2035 NDCs alone² will limit warming to 2.6°C. When binding long-term or net-zero targets are included (our “pledges and targets” scenario), warming would be limited to about 2.2°C³ above pre-industrial levels, or in probabilistic terms, likely (66% or greater chance) limit warming below 2.4°C.

We also ran an “optimistic” scenario analysing the effect of net zero emissions targets announced in over 140 countries (both adopted and under discussion). Under the optimistic assumption that governments will achieve these targets, the median warming estimate is 1.9°C, or in probabilistic terms, likely below 2.1°C.

See our November 2025 briefing for full details.

There remains a substantial gap between what governments have promised to do and the total level of actions they have undertaken to date. Furthermore, both the current policy and pledge trajectories lie well above emissions pathways consistent with the Paris Agreement long-term temperature goal.

The science is clear: limiting warming to 1.5°C above pre-industrial levels requires rapid reduction of greenhouse gas emissions - approximately halving them by 2030 and reaching net-zero soon after mid-century.

The CAT evaluates progress towards this global goal by first quantifying emissions pathways under four distinct scenarios that aggregate the effects of countries' current policies or pledges and targets, and compares these with the emissions levels consistent with the 1.5°C limit. This is done using the MAGICC climate model (see Methodology section) which generates temperature pathways and end of century warming estimates (including probability ranges), as presented in the CAT thermometer.

The CAT determines a 1.5°C compatible benchmark using pathways from the IPCC AR6 pathways that limit warming to 1.5°C with no or low overshoot, and that are compatible with reaching net zero greenhouse gas emissions in the second half of this century, consistent with the Paris Agreement’s Articles 2.1 and 4.1.

Reaching net-zero global greenhouse gas emissions in the second half of the century is important to align with Article 4.1 of the Paris Agreement and reduce climate change impacts. Pathways that achieve this in the IPCC AR6 fall in the IPCC's "C1a" category of pathways.

The CAT determines the 1.5°C compatible pathway based on latest science from the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR6) and careful selection of emissions pathways from the AR6 scenario database.

We select only scenarios that limit warming to 1.5°C with no or low overshoot and that are compatible with reaching net zero greenhouse gas emissions in the second half of this century, consistent with the Paris Agreement’s Articles 2.1 and 4.1. Pathways that meet this criteria fall in the IPCC's "C1a" category of pathways, which are further filtered to avoid pathways that rely on unsustainable levels of carbon capture and storage (CCS) and/or unsustainable levels of carbon dioxide removal (CDR) from afforestation/reforestation (AR) or bioenergy use with CCS (BECCS).

Carbon capture and storage technologies, critical for fossil CCS and BECCS, are still immature and feasibility for large-scale deployment is very unclear. In addition, BECCS and carbon sequestration through afforestation/reforestation can have significant negative impacts when deployed at scale, including competition with food production, high water and fertiliser demands, and biodiversity loss (Heck et al, 2018).

Pathways with lower reliance on CCS and CDR generally reduce emissions faster than those which deploy large amounts of these technologies (Grant et al, 2021a, 2021b), and so by selecting for pathways with limited CCS/CDR we ensure consistency with sustainability limits identified by the IPCC, and see faster emissions reductions out to 2030. The currently used sustainability criteria are:

1. Limiting carbon sequestration via BECCS to 5GtCO₂/y in 2050 (Fuss et al, 2018)
2. Limiting carbon sequestration via Afforestation and Reforestation to 3.6GtCO₂/y in 2050 (Fuss et al, 2018)
3. Limiting deployment of fossil CCS to 3.8GtCO₂/y in 2050 (IPCC, 2022).

To give a better sample of scenarios relevant to the period to pre-2050 the CAT also considers pathways in the IPCC AR6 C1b category that do not reach net zero GHGs at a global level by 2100 but that show similar or faster emissions cuts over the next few decades to the C1a set. Many of the C1b pathways display faster decarbonisation in the 2020-2050 period because they explore how we could limit warming to 1.5°C without achieving net-negative CO₂ emissions (Riahi et al, 2021). Without this possibility, emissions need to fall even faster in the 2020s.

These pathways do not reach net-zero GHGs because CO₂ emissions fall to zero, but do not become significantly negative. That is, they reach net-zero CO₂ emissions, but no net-zero GHG emissions. To achieve net-zero GHG, net negative CO₂ emissions would be needed to compensate for residual CH4 and N2O emissions that may be impossible to eliminate fully (e.g., from agriculture).

Many of the C1b pathways (16 out of 24 selected C1b pathways) do not achieve net zero GHGs because of choices made in their design to prevent CO₂ emissions becoming net negative (Riahi et al 2021). These pathways provide valuable information on the near-term emissions reductions required to minimise carbon budget overshoot and avoid reliance on net-negative CO₂ emissions, but do not provide information on the long-term energy system configurations required to reach net-zero GHGs.

Most of the remaining 8 C1b pathways limit the level of CO₂ removal to very low levels (Luderer et al 2021, Strefler et al 2021), which prevents net-zero GHGs being met.

The CAT only includes C1b pathways if they pass the sustainability filters for CCS and CDR, and if they reduce emissions from 2020-2050 faster than the corresponding C1a pathways. This ensures that, although these pathways do not hit net-zero in the long-term, they are consistent with achieving net-zero GHGs in the second half of the century, as they reach lower emissions levels by 2050 than corresponding C1a pathways. Indeed, the faster decarbonisation of the global energy system pre-2050 means that these pathways would be well placed to achieve net-zero GHGs in the second half of the century with reduced reliance on carbon dioxide removal.

This represents a precautionary approach, where these additional pathways help ensure that our final 1.5°C compatible pathway is not overly reliant on achieving negative emissions (the feasibility of achieving which is challenging, as argued above). Post-2050, these C1b pathways are not included in the CAT’s 1.5°C compatible benchmark, as they do not achieve net-zero greenhouse gas emissions as required by the Paris Agreement.

1 | 2.6°C is the median of the combined low and high current policy scenarios.
2 | For those countries, who are overachieving their NDCs, we take the upper end of their current policy projections as the limit. We project the global effects beyond the NDC timeframes assuming policies of a similar strength are implemented through to the end of the century.
3 | The uncertainty range for the “pledges and targets” scenario on the CAT thermometer (1.8-2.8°C) originates from carbon-cycle and climate modelling using the MAGICC model around pledges and targets scenario. Here we give the 68% range; that is the 16th and 84th percentiles of the probability distribution. If the more ambitious end of the pledges and targets range was reached, warming could be limited to a median of 1.9°C. This includes the stronger end of country NDCs where a reduction range is specified and mitigation commitments that are conditional on finance.

For more results linked to our most recent Global temperature update see:

• Our full global temperature update briefing
• CAT thermometer
• Emissions gaps for 2035

For the latest on NDC updates, please refer to our Climate Target Update Tracker as well as our briefing detailing our 2030 and 2035 NDC target recommendations for major emitters to align to 1.5°C. For the latest in country developments, see our country assessments.

For more information on the global emissions and temperature pathways and how they are calculated, please refer to our methodology section.

Last update: 13 November 2025

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