Network records Europe's greenhouse gas emissions

Half of the carbon emissions released to the atmosphere by fossil fuel use are re-captured by the ocean and land ecosystems. However, we still have many open questions. A recent article in The Bulletin of American Meteorological Society (BAMS) describes for the first time the structure and functioning of the Integrated Carbon Observation System (ICOS) Research Infrastructure.

What is the exact size, nature and stabilities of so-called ocean and land carbon sinks? How will they be affected by climate change? How do these sinks operate in detail, do they continue in the future? How do potential changes affect the atmospheric greenhouse gas concentrations? Answers to these questions are vital information for societies that must decide on pathways to climate neutrality.  

"We have the tools to measure these greenhouse gas fluxes. Some of us measure them since decades. And only with such long-term, harmonised time series can we detect and understand the response of the biosphere to slow changes in climate”, says Nina Buchmann, Professor of Grassland Sciences at ETH Zurich, Head of ICOS Switzerland and co-author of the article.

The article lifts a number of particularly important scientific questions in the field. Due to the growing urgency of climate change, many of these questions relate to policy frameworks such as the Paris Agreement or to the UN Sustainable Development goals. For example, ICOS is involved in providing important basic information to an envisaged EU monitoring and verification support system for greenhouse gas emissions. In this context, radiocarbon methodology is used in quantifying the emissions from fossil fuel burning, as carbon dioxide from fossil fuel sources is void of the radioactive carbon isotope, 14C.

Further research is needed on lateral carbon fluxes from land into oceans, which can currently only be quantified with large uncertainty. Indeed, while ICOS has taken some initial steps to build capacities to quantify also these fluxes, a lot remains to be done yet.

Further, the authors state that more accurate observations are needed in urban areas, since these densely populated areas are fossil fuel emission hotspots, and constantly growing. The success in emission reductions will be first visible there. ICOS is responding to this challenge by kicking off a new EU project “ICOS Cities – Pilot Applications in Urban Landscapes”. Two Swiss cities, Zurich and Basel, are part of the ICOS Cities project, with ICOS Switzerland partners from Empa and the University of Basel. An urban station in Basel will soon complement the Swiss stations within ICOS.

“With ICOS Cities, we aim to test different observation methods, by designing and building urban pilot observatories. We want to test and showcase different tools and services to process and analyse these observations, and do it all in a way that responds to the needs of the cities and supports them in realising their climate action plans,” tells Werner Kutsch, Director General of ICOS, and the coordinator of the project.

On a larger scale, the article mentions the compilation of a European carbon and greenhouse gas budget, which until now has only been possible with a considerable one-time effort. Soon, it could be produced annually, at high spatial resolution and with reduced uncertainty. This type of product would clearly benefit political actors to decide on the most feasible climate actions, like it was recently done at the Climate Conference COP26 in Glasgow.

In conclusion, there are several urgently needed developments in the field of carbon science: how to detect climate change effects on the terrestrial and ocean sinks, how to best support the verification of national and local GHG inventories, and how to validate the efficacy of mitigation actions.

The ICOS article is published in The Bulletin of American Meteorological Society (BAMS).