Climate Response Dynamics to Carbon Dioxide Emissions

The climate response to carbon dioxide emissions is governed by a sequence of interconnected processes that link anthropogenic carbon release to atmospheric concentration, radiative forcing and global temperature change. In the short term, increased CO₂ elevates incoming and outgoing radiation balance, driving surface warming. A portion of emitted CO₂ is taken up by the ocean and terrestrial biosphere, modulating atmospheric concentration but also leading to ocean acidification and altered carbon storage in soils and vegetation. Over decades to centuries, heat penetrates into the deep ocean, and carbon redistributes across reservoirs, producing commitments to further warming even if emissions cease. The near‐linear relationship between cumulative CO₂ emissions and global temperature change underpins the concept of a carbon budget, which quantifies allowable emissions to meet specific warming targets. However, non‐linearities emerge during periods of net negative emissions and under temperature overshoot scenarios, reflecting the inertia of ocean heat uptake and the varying efficiency of natural carbon sinks. Understanding these dynamics is critical to inform mitigation pathways, design durable carbon dioxide removal strategies and anticipate long-term feedbacks that shape the efficacy of climate policy.

Research from Nature Portfolio

Recent studies have refined estimates of the carbon budget for 1.5 °C and 2 °C of warming by integrating historical observations with Earth System Model projections. These analyses confirm a maintained linear proportionality between cumulative emissions and warming up to around 4 °C, while narrowing uncertainties on remaining allowable emissions. Investigations into the marine carbon sink under scenarios of temperature overshoot reveal that, although physico-chemical uptake of CO₂ may diminish or reverse during net-negative emission phases, the biological carbon pump continues to sequester carbon and may dominate ocean storage on multi-centennial timescales. This finding highlights the importance of including biological mechanisms when projecting oceanic CO₂ uptake in mitigation strategies. In parallel, assessments of carbon dioxide removal durability demonstrate that storage duration critically influences temperature outcomes: temporary storage (for example, centennial scale) falls short of permanently neutralising residual emissions, whereas multi-millennial storage in geological or biogenic reservoirs is required to sustain net zero targets without additional warming.

Climate Response Dynamics to Carbon Dioxide Emissions publication trend

The graph below shows the total number of articles in climate response dynamics to carbon dioxide emissions across all publications each year (not limited to Nature Index journals).

Technical terms

Carbon budget: The cumulative amount of CO₂ emissions compatible with a specified limit on global temperature rise.

Transient Climate Response to cumulative carbon Emissions (TCRE): The ratio of global temperature change to cumulative CO₂ emissions, reflecting near-linear warming behaviour.

Biological carbon pump: The process by which marine organisms transport carbon from the surface ocean to the deep sea through biological production and sinking organic matter.

Carbon dioxide removal (CDR): A suite of techniques that extract CO₂ from the atmosphere and store it in durable reservoirs to achieve net negative emissions.

Ocean acidification: The decrease in seawater pH resulting from absorption of excess atmospheric CO₂, with implications for marine chemistry and ecosystems.

References

1. Emergent constraints on carbon budgets as a function of global warming. Nature Communications (2024).
2. Marine carbon sink dominated by biological pump after temperature overshoot. Nature Geoscience (2024).
3. Durability of carbon dioxide removal is critical for Paris climate goals. Communications Earth & Environment (2024).
4. Asymmetric response of South Asian summer monsoon rainfall in a carbon dioxide removal scenario. npj Climate and Atmospheric Science (2023).
5. Ocean acidification in emission-driven temperature stabilization scenarios: the role of TCRE and non-CO2 greenhouse gases. Environmental Research Letters (2023).
6. Is there warming in the pipeline? A multi-model analysis of the Zero Emissions Commitment from CO2. Biogeosciences (2020).
7. Carbon dioxide and climate impulse response functions for the computation of greenhouse gas metrics: a multi-model analysis. Atmospheric Chemistry and Physics (2013).