Integrated Assessment of Climate Policy and Energy Systems

Integrated assessment of climate policy and energy systems brings together models of the economy, energy supply and demand, land use, and the climate to evaluate pathways towards mitigation targets. By coupling representations of technology costs, behavioural responses, policy instruments and climate dynamics, integrated assessments explore the trade-offs and synergies between decarbonisation options. They inform decision-makers on feasible routes to net-zero emissions, quantify the remaining carbon budget consistent with temperature limits, and highlight uncertainties arising from model structure, socioeconomic assumptions and technological developments. Scenario analysis within this framework underpins global negotiations, national strategies and sectoral roadmaps, while ongoing methodological advances aim to improve transparency, comparability and the representation of critical feedbacks such as land-use change, carbon capture and storage, and non-CO2 greenhouse gases. The resulting insights serve to align long-term climate objectives with short-term policy choices, fostering coherent transitions across sectors and regions.

Research from Nature Portfolio

Recent studies have attributed variation in scenario outcomes to underlying drivers through advanced sensitivity analysis. One analysis applied Sobol decomposition to a suite of global models, revealing that the choice of climate target dominates outcomes for emissions, renewable deployment and carbon removal, while structural differences between models explain divergence in sectoral pathways and technology mixes. This work clarifies where consensus exists and where model dependency is strongest, guiding more robust interpretation of scenario ensembles.

Another investigation introduced a diagnostic framework to fingerprint energy models according to their responsiveness, mitigation strategies, supply and demand representation, and cost assumptions. By comparing indicator profiles across eight models under a common set of European scenarios, researchers identified systematic biases in technology adoption and effort sharing, providing a basis for more targeted multi-model comparisons and policy evaluation.

Complementing these methodological advances, a third study examined global fossil-fuel reduction trajectories consistent with 1.5 °C and 2 °C limits. It quantified average declines in coal, oil and gas use to mid-century, and explored the sensitivity of higher-gas pathways to assumptions about carbon capture and storage capacity. The findings emphasise the need for clear benchmarks on fossil-fuel supply and rapid deployment of removal technologies to maintain policy credibility.

Integrated Assessment of Climate Policy and Energy Systems publication trend

The graph below shows the total number of articles in integrated assessment of climate policy and energy systems across all publications each year (not limited to Nature Index journals).

Technical terms

Integrated Assessment Model (IAM): A computational framework that couples economic, energy, land‐use and climate modules to evaluate policy scenarios and their environmental outcomes.

Carbon Budget: The total amount of CO2 emissions permissible to limit global warming to a specified temperature threshold.

Carbon Capture and Storage (CCS): A technology to capture CO2 from industrial or energy processes and store it underground to prevent atmospheric release.

Net-Zero Emissions: A state in which anthropogenic greenhouse-gas emissions are balanced by removals via sinks or engineered technologies.

References

1. Spread in climate policy scenarios unravelled. Nature (2023).
2. Identifying energy model fingerprints in mitigation scenarios. Nature Energy (2023).
3. Global fossil fuel reduction pathways under different climate mitigation strategies and ambitions. Nature Communications (2023).
4. Economic mitigation challenges: how further delay closes the door for achieving climate targets. Environmental Research Letters (2013).
5. GCAM v5.1: representing the linkages between energy, water, land, climate, and economic systems. Geoscientific Model Development (2019).
6. Zero emission targets as long-term global goals for climate protection. Environmental Research Letters (2015).