Modern Carbon Cycle

Carbon Cycle

Carbon Cycle (original image credit:

Project Leader: Jocelyn Turnbull

This project aims to understand and model the source and fate of human-produced carbon dioxide (CO2) emissions.

CO2 emissions are known to be the primary driver of the current observed global warming, yet there are a number of gaps in our understanding of the rate of emissions, and in the resulting build-up of CO2 in the atmosphere.

Radiocarbon (14C) measurements are an excellent tool for investigating CO2 emissions and their ultimate fate. Our laboratory uses measurements of 14C in CO2, along with atmospheric transport modelling, to quantify fossil fuel CO2 emissions into the atmosphere at various scales, including individual power plants, urban areas and entire countries and regions. This research will be essential to ensure regulation of fossil fuel CO2 emissions is effective.

Of the fossil fuel CO2 emissions to the atmosphere, only about half remains in the atmosphere, with the remainder being absorbed into the oceans and terrestrial biosphere. The details of this uptake of human-produced CO2 are still uncertain, yet knowledge of the rate and mechanisms of the CO2 uptake is critical for predictions of future climate change. The Southern Ocean in particular is a strong “sink” for human-produced CO2, yet it is possible that climate change will reduce the Southern Ocean’s capacity to absorb that CO2 – a positive climate change feedback. We use 14CO2 measurements over the Southern Ocean as a diagnostic for understanding the mechanisms of ocean carbon exchange.

Recent updates and outputs

  • To learn more about natural and human drivers of carbon emissions and their effects on climate, check out the Radio NZ Our Changing World interview with some of our leading climate change scientists.

See Outputs and Outcomes for our latest publications.