An international research project on the global carbon cycle

The project called CALIPSO is an international research project funded through a gift from the Virtual Earth System Research Institute (VESRI), an initiative of Schmidt Futures, and is co-led by the Laboratoire des Sciences du Climat et de l'Environnement, the University of Exeter and the University of East Anglia, with Stockholm University as a collaborating institution. Stefano Manzoni and Gustaf Hugelius at the Department of Physical Geography, Stockholm University will work on the vulnerability of soil carbon, focusing on mapping carbon storage in permafrost and on modelling microbial responses to changes in environmental conditions. 

This opportunity to work in a large and truly international consortium with leading global experts gives us a unique chance to use new methods to tackle some of the largest remaining challenges in our understanding of the Earth’s carbon cycle, and to better understand how we humans are changing that carbon cycle. I am really looking forward to working with this group and to see what new knowledge we can achieve together, says Gustaf Hugelius. 

Focus on new representation of carbon loss pathways from plants, soils and ocean

This ambitious multi-year project aims to understand the fate of future CO2 and climate change through a new representation of carbon loss pathways from plants, soils and ocean, by leveraging novel observations, theoretical understanding, machine learning tools and integration of processes with Earth system models. 

A rapidly eroding permafrost coast in northwestern Canada exposes massive amounts of previously frozen soil. Photo: Gustaf Hugelius.

The fate of carbon emissions from fossil fuel burning and deforestation determines the rate of increase of atmospheric CO2 increase, and in turn, climate change. The physics-based models used for future climate projections predict a weakening of both land and ocean sinks (e.g. absorption) in response to a warming climate, resulting in a steeper rise in atmospheric CO2. The magnitude of this amplifying carbon-climate feedback differs by a factor of five among current models, which significantly hinders future climate projections, especially for high warming projections if carbon emissions are not cut rapidly towards zero. 

Many known terrestrial and marine ecosystem processes that could reinforce or weaken this feedback are missing or poorly represented in current models. Thus, the key research question being addressed by the CALIPSO researchersfocuses on the extent to which the natural carbon cycle may be destabilized by climate change.

Biological carbon loss and mortality processes are major gaps in our current knowledge of the carbon cycle, which have been ignored or oversimplified in current models, failing to reproduce the observed complexity of living systems, explains Philippe Ciais, senior researcher at Laboratoire des Sciences du Climat and coordinator of the CALIPSO project. 

How will climate change impact tree mortality, and the fate of carbon in ocean and soil?

To better understand how increasingly frequent extreme events may trigger a destabilization of biological carbon reservoirs, an international team of leading scientists across six countries will work together in the CALIPSO project to develop biologically accurate representation of how climate change will impact the mortality and resilience of trees following drought and fire, the efficiency of diverse soil microbial communities that decompose organic matter, and the recycling and deep export of ocean carbon resulting from activities of viruses and diverse zooplankton communities. 

In CALIPSO, we will quantify how much carbon soils are losing because warming and changes in rainfall regimes alter the way soil microbes decompose organic matter, especially in vulnerable permafrost. We know that microbes are adapting to these changing conditions, and expect that adaptation could cause larger carbon losses than models predict so far—quantifying these effects will be a fundamental step for better prediction of the future carbon cycle, says Stefano Manzoni.

Sampling the frozen soil underlying the mosquito-rich tundra by hammering a steel corer into the permafrost. Photo: Gustaf Hugelius.

CALIPSO can fill in critical knowledge gaps in the global carbon cycle

We expect that CALIPSO will make a giant leap in the representation of carbon loss processes in climate models and fill in critical knowledge gaps in the global carbon cycle. All the model codes and data collected in the project will be publicly available, to benefit the research community and help develop a new generation of models that will accurately predict the fate of future CO2 and climate change and the risks to our planet.

Contacts 

Stefano Manzoni
Epost: stefano.manzoni@natgeo.su.se
Telefon: +46-8-674 78 02

Gustaf Hugelius
Epost: gustaf.hugelius@natgeo.su.se
Telefon: +46-8-674 78 73