CARBOCHANGE

The project is funded by EU FP7 and coordinated by Prof. Christoph Heinze, co-leader of the Biogeochemistry research group at Geophysical Institute, University of Bergen.

The goal of CARBOCHANGE is to provide the best possible quantification of carbon uptake in the ocean under changing climate conditions in order to predict how the ocean´s role as key regulator of CO₂ will behave in the future.

What´s the problem?

The ocean is the key buffering agent for atmospheric CO₂ in the Earth System, by being the major sink of the excess CO₂ spewed by human activities. In this regard, the ocean is expected to be the sole absorber (up to 90%) of most of human-produced CO₂ in the future. However, because the ocean processes are slow, this buffering capacity is effective only on long time scales. In addition, the efficiency depends on the timing of the emissions as well as the physical and biogeochemical processes which may enhance or slow-down its buffering effect. This means that one cannot prevent a temporary build-up of anthropogenic CO₂ in the atmosphere due to a (most likely) steep rise in atmospheric CO₂ during the coming decades, unless a fundamental change in carbon emission´s policies occur.

Previous research, also led by Prof. Heinze (see CARBOOCEAN) has shed new light on the operation of the ocean as a carbon buffer. For instance, there are substantial temporal - previously not recognized - changes in the carbon uptake rates of  the North Atlantic and Southern Ocean, the two major areas of the World Ocean where deep mixing down to the ocean bottom occurs. Changes in the behavior of the ocean as a carbon sink requires thorough monitoring, if one is to predict the vulnerability of the ocean buffering capacity under climate change.

How will it be done?

CARBOCHANGE will combine observational data with model simulations. It will

• upscale new process understanding to large-scale integrative feedbacks of the ocean carbon cycle to climate change and rising carbon dioxide concentrations.
• quantify the vulnerability of the ocean carbon sources and sinks in a probabilistic sense using cutting edge coupled Earth system models under a variety of emission scenarios, including climate stabilisation scenarios as required for the 5th IPCC assessment report.
• identify the drivers for the vulnerabilities. The most actual observations of the changing ocean carbon sink will be systematically integrated with the newest ocean carbon models, a coupled land-ocean model, an Earth system model of intermediate complexity, and fully fledged Earth system models through a spectrum of data assimilation methods as well as advanced performance assessment tools.

Why is this important?

Policy makers need climate projections to be able to implement sound mitigation and adaptations measures but the problem is that present climate projections are highly uncertain. A key issue is thus to reduce the error margins that plague many of the model results, yielding inaccurate predictions.  Some of this uncertainty is due to the lack of knowledge on how the absorbing capacity of the ocean will behave in the future, given the expected acceleration in human CO₂ emissions. With CARBOCHANGE providing more realistic estimates of ocean carbon uptake, it will have a direct and significant impact on future regulation of carbon emissions.

"CARBOCHANGE is the key European research effort of the coming 4 years to provide policy makers with firm numbers on the marine sink of human-produced carbon dioxide (CO₂), the most important driver of modern climate change and progressing ocean acidification. [...] A quick reaction of policy makers is required in order to limit (a) human-induced climate change due to rising greenhouse gas accumulation in the atmosphere and (b) the associated CO₂ pollution of the oceans. Both aspects must enter international greenhouse gas emission reduction treaties and substantial efforts to redesign our energy systems. CARBOCHANGE will provide science-based guardrails for respective decisions.", says Prof. Heinze.

International assessments

The outcome of CARBOCHANGE will contribute to major international assessments, such as the IPCC´s 5^th Assessment Report to be published in 2014.

The project will also deliver calibrated future evolutions of ocean pH and carbonate saturation as required by the research community on ocean acidification, such as the project EPOCA and further projects in this field.

The time history of atmosphere-ocean carbon fluxes past, present, and future will be synthesised globally as well as regionally for the transcontinental Regional carbon cycle assessment and processes (RECCAP) project. Observations and model results will merge into the Global Earth Observations Systems of Systems (GEOSS) under the Group on Earth Observations (GEO) through links with the European coordination action on carbon observation system (COCOS) and will prepare the marine branch of the European Research Infrastructure Integrated carbon observation system (ICOS).

For further information contact:

Prof. Christoph Heinze, christoph.heinze@gfi.uib.no