1- Interactions Biosphère-Atmosphère

To what extent can a better knowledge of Biosphere-Atmosphere interactions help to better manage land use?

Among the outcomes of Flagship project 1 (2013-2016), an advocacy for the development of regional climate action.

Leaders: Nathalie DE NOBLET (LSCE) and Pierre CELLIER (ECOSYS)
Partners:

The main question underlying the research conducted in this flagship project is: "To what extent can a better knowledge of biosphere-atmosphere interactions help to better manage land use? Can being able to quantify these interactions allow us to think about the best management of urban, peri-urban and rural environments? ".

This project is based on the twofold observation that (i) climate change has repercussions on the scale of territories, which can be different depending on their natural characteristics, land use and the use made of them by man, (ii) the changes in land use made by man, independently of (or as a function of) climate change, influence the climate on the scale of the region concerned. These two effects are notably due to the exchange of energy and atmospheric pollutants and greenhouse gases in the agricultural, forestry and urban systems of these territories.

Flagship project 1 has led to in-depth exchanges and interdisciplinary projects associating climate and atmospheric sciences (LSCE), environmental sciences (ECOSYS), social and economic sciences (SADAPT, CEARC), with also an association with local partners (Terre&Cité) or the economic sector (Kinomé). Exchanges with the flagship projects 4 and 5 can also be highlighted.

Through the research projects initiated and supported by Flagship Project 1, we have worked to develop tools for assessing impacts at the territorial level, to analyze the feedbacks between land use and regional climate, and to analyze the roles of stakeholders and public policies in the areas of land use and management, against the backdrop of regional climate and air quality.

The aim of the work carried out as part of a post-doctoral contract was to establish the extent to which the influence of soils and their uses on the regional climate could be integrated into the planning action of the territories. To this end, we conducted (i) a textual analysis of territorial planning documents adopted in the Île-de-France region (SCoT) and (ii) an exploration of the ways in which planning actors could integrate knowledge of surface-atmosphere interactions at a regional scale. These analyses, aimed at planners among others, will be based on the writing of a literature review article currently being finalized for the journal Biogeosciences: "Influences of landscape structure and land uses on local to regional climate and air quality: A review of surface-atmosphere interactions and feedbacks".

A second post-doctoral contract sought to quantify the impacts of land use change on regional climate in France, in the context of future climate change, using the WRF-ORCHIDEE regional climate model. Both land use changes and climate change, imposed on the regional model, are derived from the scenarios of the latest IPCC exercise.

A doctoral contract has focused on the functioning and distribution of hot semi-arid zones worldwide in connection with Kinomé to better inform strategies and recommendations for reforestation of semi-arid tropical areas.
Finally, with the help of a CDD engineer and in connection with Terre&Cité, we worked to clarify the evolution of the climate and its impacts on agriculture on the Saclay plateau, in particular in order to work with the farmers of the plateau.

==> Find the powerpoint presentation of the project results (LabEx Scientific Days 2017)

Publications (non exhaustif)

> Massad, R.S., Lathière, J., Strada, S., Perrin, M., Personne, E., Stéfanon, M., Stella, P., Szopa, S., de Noblet-Ducoudré, N., 2019. Reviews and syntheses: influences of landscape structure and land uses on local to regional climate and air quality. Biogeosciences 16, 2369–2408. https://doi.org/10.5194/bg-16-2369-2019

> Caubel, J., Cortazar-atauri, I. G. De, Vivant, A. C., Launay, M., & Noblet-ducoudré, N. De., 2017. Assessing future meteorological stresses for grain maize in France. Agricultural Systems. http://doi.org/10.1016/j.agsy.2017.02.010.

> PERRIN, M.; De NOBLET-DUCOUDRÉ, N.; STRADA, S. & TORRE, A., 2017. Research Note. ADVOCACY for the development of a regional climate action: spatial planning, land use and atmospheric conditions. Norois - Environment, Planning, Society.
"Following an awareness of the problem of global warming and the recognition of anthropogenic responsibility for the phenomenon, the climate issue has gradually become a central concern for land-use planning. Particular attention has been paid to spatial and urban arrangements likely to reduce greenhouse gas emissions, the approach being intended as a contribution to the global effort to mitigate climate change. In addition, with a view to adaptation, planners are gradually showing renewed interest in the principles of urban climatology and bioclimatology in urban areas that could well see their atmospheric conditions become warmer. The comfort and health of many populations are at stake. Through this note, we argue for the possibility of extending the scope of climate action by developing a capacity to influence atmospheric conditions at a scale that can be described as regional or intermediate. Research in regional climatology has highlighted the significant influence that changes in land use and management can have on the meteorology and air quality of a region through the exchange of energy, water and chemicals between the surface and the atmosphere. We outline, based on selected case studies in the literature, what such regional climate action might look like, and then point out some of the challenges that need to be addressed for it to come into being."

© Pierre Donnaint UNESCO photobank

Thesis

> Reforesting the semi-arid tropics? : Climatic stakes, constraints and opportunities in the perspective of global change - Amélie RAJAUD (IDEX Paris-Saclay doctoral initiative funding), defended in September 2016
Communications at scientific events

> International conferences: American Gophysical Union AGU, European Geosciences Union EGU...
Popularization
> EXHIBITION panels on "Climate change and agriculture in Ile-de-France: history, analysis and simulation of impacts on the main cultivated plant species" have been produced and presented on various occasions in the Ile de France region.