Our Common Future Under Climate Change

International Scientific Conference 7-10 JULY 2015 Paris, France


Our Common Future under Climate Change - Outcome Statement

CFCC15 Scientific Committee*, chaired by Chris Field 
Chairs of the Organising and High-Level Committees: Hervé Le Treut and Jean Jouzel 
International organisers: UNESCO, Future Earth, and ICSU**

July 10, 2015

In addition to CFCC15 Scientific Committee*, chaired by Chris Field
Chairs of the Organising and High-Level Committees: Hervé Le Treut and Jean Jouzel
International organisers: UNESCO, Future Earth, and ICSU**   

Before Cop21 t
he statement has been signed by a number of scientific institutions and international research programs.
List below.

Science Offers Robust Foundations for Ambitious Outcomes at COP21 and Beyond

The scientific conference “Our Common Future under Climate Change” (CFCC15*) covers the full landscape of scientific knowledge on climate change. The largest international science conference before the Paris COP21, with close to 2,000 participants from almost 100 countries, CFCC15 explores current understanding of all dimensions of the climate change challenge plus the full range of mitigation and adaptation options that can lead to sustainable, equitable solutions across all nations and regions.

The main objective of COP21 in December 2015 is to produce a cooperation framework among governments for a steady increase of individual and collective ambitions for addressing the challenge of climate change. The new climate governance regime is intended to strengthen confidence, support implementation, maximize benefits of international cooperation, and cement awareness that a new development model (low to zero carbon, resilient) is emerging. For science, the opportunity is progressively broadening from assessing risks and options to also understanding and helping enable transition pathways to sustainable, resilient economies and societies.

This statement distils the scientific foundation for action, building on current understanding of the solution space and the problem space.

Climate change is a defining challenge of the 21st century. Its causes are deeply embedded in the ways we produce and use energy, grow food, manage landscapes and consume more than we need. Its effects have the potential to impact every region of the Earth, every ecosystem, and many aspects of the human endeavour. Its solutions require a bold commitment to our common future.

Because warming from carbon dioxide persists for many centuries, any upper limit on warming requires carbon dioxide emissions to fall eventually to zero. A two in three probability of holding warming to 2°C or less will require a budget that limits future carbon dioxide emissions to about 900 billion tons, roughly 20 times annual emissions in 2014. To limit warming to 2°C, emissions must be zero or even negative by the end of the 21st century.

Smart policies to manage and reduce the risks of climate change must be fair, embracing the importance of history, capabilities, equitable financing, and the richness of human experience. 2015 is a critical year for progress. The window for economically feasible solutions with a reasonable prospect of holding warming to 2°C or less is rapidly closing.

Every nation has a role. Bold action in 2015 can be decisive in assuring a common future of sustainable, robust economies, equitable societies, and vibrant communities.

Science is a foundation for smart decisions at COP21 and beyond. Solving the challenge of climate change requires ambition, dedication, and leadership from governments, the private sector, and civil society, in addition to the scientific community.

We in the scientific community are thoroughly committed to understanding all dimensions of the challenge, aligning the research agenda with options for solutions, informing the public, and supporting the policy process.


1. Ambitious mitigation to limit warming to less than 2°C above preindustrial levels is economically feasible. Delaying deep emissions cuts, waiting on the sidelines by some countries, or excluding particular clean-energy technologies all increase costs and complexity. Cost-effective mitigation pathways to limit warming to 2°C require reducing emissions of greenhouse gases by 40–70% below current levels by 2050.

2. Mitigation over the next few decades will be pivotal in determining the amount of long-term warming and associated risks. But even with ambitious mitigation, much of the climate change over the next few decades is unavoidable as a result of both climate processes and the natural lifecycle of existing technology and infrastructure. Adaptation in the near term and long term can help address risks of impacts that cannot be avoided, but there are limits to adaptation.

3. Investments in climate-change adaptation and mitigation can provide a wide range of co-benefits that enhance protection from current climate variability, decrease damages from air and water pollution, and advance sustainable development. Smart responses to climate change, designed to maximize co-benefits and minimize adverse side-effects, can be part of an integrated strategy of inclusive and sustainable development.

4. Ambitious mitigation will require a range of actions, including investing in research, development, and technology transfer; phasing out subsidies on fossil energy; and pricing carbon. Pricing carbon helps level the playing field among energy technologies by charging for the damage caused by climate change and rewarding other benefits of mitigation activities.

5. Over the rest of the century, global investments in energy and energy infrastructure will total many trillions of dollars. The additional investment required to transition to clean energy can be a small fraction of this amount. With effective implementation, this additional cost can be an important contributor to inclusive and sustainable economic growth.

6. Emissions of heat-trapping gases are simpler to reduce in some sectors than in others. Decreased deforestation, energy efficiency, electricity generation, buildings, and cars are at the simpler end of the spectrum. Aviation, heavy trucks, ocean ships, and agriculture are more complicated. Technologies with huge potential include demand management, energy efficiency, solar, wind, bioenergy, and nuclear, with the possibility of breakthroughs. Improved stewardship of the Earth presents large opportunities not only for climate but also for biodiversity and ecosystem services.


1. Warming of the climate system is unequivocal. Human activities are to blame for much of the warming to date.

2. Impacts of climate changes that have already occurred are widespread and consequential. Impacts have affected every continent, from the equator to the poles and the mountains to the coasts. Climate changes have contributed to many kinds of extremes, including heat waves, heavy rain, wildfires, droughts, and decreased snow and ice. They have made it more difficult to increase crop yields and have shifted the locations and activities of plants and animals on the land, in lakes and rivers, and in the oceans.

3. People and places around the world are vulnerable and exposed to climate change, with different risks in different places. Vulnerability is especially daunting where poverty, inequalities, lack of infrastructure, and ineffective governance combine to constrain options.

4. Continued high emissions of heat-trapping gases increase the risk of impacts that are severe, pervasive, and irreversible. Risks for people, economies, and ecosystems are all much greater in a world of continued high emissions, with warming by the end of the century potentially reaching 4°C or more above preindustrial levels, than in a world of ambitious mitigation. Risks of greatest concern include impacts on food and water security, human health and well-being, biodiversity and ecosystem services, inequalities and poverty, unique cultures, economic activities and infrastructure, and crossing of large-scale thresholds for sea level, biodiversity, and climate feedbacks.

* CFCC15 Scientific Committee:

 Chris FIELD (Carnegie Institution, USA) - Chair
• Philippe CIAIS (Climate Environment Society, France)
• Wolfgang CRAMER (Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale, France)
• Purnamita DASGUPTA (Institute of Economic Growth, India)
• Ruth DEFRIES (Colombia University, USA)
• Navroz DUBASH (Centre for Policy Research, India)
• Ottmar EDENHOFER (Potsdam Institute for Climate Impact Research, Germany)
• Michael GRUBB (University College London, UK)
• Jean-Charles HOURCADE (Centre national de la recherche scientifique [INRA], France)
• Sheila JASANOFF (Harvard Kennedy School of Government, USA)
• Kejun JIANG (Nanyang Technological University, China)
• Vladimir KATTSOV (Main Geophysical Observatory, Russia)
• Hervé LE TREUT (CNRS-Université Pierre et Marie Curie, France)
• Emilio LEBRE LA ROVERE (National University, Brazil)
• Valérie MASSON-DELMOTTE (Laboratoire des Sciences du Climat et de l’Environnement/Institut Pierre Simon Laplace, France)
• Cheikh M’BOW (World Agroforestry Centre [ICRAF], Kenya)
• Isabelle NIANG-DIOP (Institut de recherche pour le développement, Senegal)
• Carlos NOBRE (Centro Nacional de Monitoramento e Alertas de Desastres Naturais [Cemaden/MCTI], Brazil)
• Karen O’BRIEN (University of Oslo, Norway)
• Joy PEREIRA (University Kebangsaan, Malaysia)
• Shilong PIAO (Peking University, China)
• Hans-Otto PÖRTNER (Alfred Wegener Institute, Germany)
• Monika RHEIN (University of Bremen, Germany)
• Johan ROCKSTRÖM (Stockholm University, Sweden)
• Hans-Joachim SCHELLNHUBER (Potsdam Institute for Climate Impact Research, Germany)
• Robert SCHOLES (University of Witwatersrand, South Africa)
• Pete SMITH (University of Aberdeen, UK)
• Youba SOKONA (The South Centre, Switzerland)
• Jean-François SOUSSANA (Institut national de la recherche agronomique [INRA], France)
• Mark STAFFORD-SMITH (Commonwealth Scientific and Industrial Research Organisation, Australia)
• Thomas STOCKER (University of Bern, Switzerland)
• Laurence TUBIANA (Institut du développement durable et des relations internationales, France)
• Diana ÜRGE-VORSATZ (Central European University, Hungary)
• Penny URQUHART (Independent analyst, South Africa)
• Carolina VERA (University of Buenos Aires, Argentina)
• Alistair WOODWARD (University of Auckland, New Zealand)

** International Council for Science (ICSU) President, Gordon McBean


Research Institution / International Research Program
African Climate & Development Initiative, University of Cape Town Cape Town South Africa
AllEnvi (Alliance nationale de recherche pour l'environnement) Paris France
ANCRE (Alliance Nationale de Coordination de la Recherche pour l'Energie) Paris France
ANR (Agence Nationale de la Recherche) Paris France
Asian Institute of Technology Pathumthani Thailand
Atmospheric Physics and Climatology of the Academy of Athens Athens Greece
BRGM (Bureau de Recherches Géologiques et Minières) Paris France
British Geological Survey Nottingham United-Kingdom
Center for Earth System Science, Tsinghua University Beijing China
Central European University Budapest Hungary
Centre Scientifique de Monaco Monaco Monaco
Centro de Estudios Ambientales y de Biodiversidad Universidad del Valle de Guatemala Guatemala Guatemala
CEREMA (Centre d’Etudes et d’Expertise sur les Risques, l’Environnement, la Mobilité et l’Aménagement) Bron France
Chiang Mai University Chiang Mai
CIEDA (Centro Internacional de Estudios de Derecho Ambiental) Soria Spain
CIRAD (Centre de coopération Internationale en Recherche Agronomique pour le Développement)
Paris France
Climate Accountability Institute Snowmass United-States
CNES (Centre National d'Etudes Spatiales) Paris France
CNRS (Centre National de la Recherche Scientifique) Paris France
Complutense University of Madrid Madrid Spain
CONAE (Comisión Nacional de Actividades Espaciales) Buenos-Aires Argentina
Conférence des Grandes Ecoles Paris France
Cork Institute of Technology Cork Ireland
Corvinus University of Budapest Budapest Hungary
COSPAR (Committee on Space Research) Paris France
CPU (Conférence des Présidents d'Université) Paris France
Cranfield University Cranfield United-Kingdom
CTSB (Centre Scientifique et Technique du Bâtiment) Champs sur Marne France
Department of Oceanography, University of Dhaka Dhaka Bangladesh
DIW Berlin - German Institute for Economic Research Berlin Germany
DNR College, Andhra University Bhimavaram India
Dublin City University Dublin Ireland
Durham University Durham United-Kingdom
Earth System Science Centre Sao Jose dos Campos Brazil
Environmental Studies Department, CASE, University of Mindanao Davao Philippines
Eötvös Loránd University Budapest Hungary
ERI (Energy Resources Institute) Beijing China
EYAS (Egyptian Young Acadmy of Science) Cairo Egypt
Federal University of Itajuba Itajuba Brazil
Finnish Meteorological Institute Helsinki Finland
FRB (Fondation pour la Recherche sur la Biodiversité) Paris France
GEO Secretariat (Group on Earth Observations)
Geneva Switzerland
Global Change Programme, Jadavapur University Calcutta India
Global Young Academy Berlin Germany
ICCCAD (International Centre for Climate Change and Development) Dhaka Bangladesh
ICSU - Health and Wellbeing in Changing Urban Environment programme New-Delhi India
ICSU-IAMP-UNU Programme on Urban Health and Wellbeing: A Systems Analysis Approach Xiamen China
ICSU - World Data System Tokyo Japan
IFPRI (International Food Policy Research Institute) Washington D.C. United-States
IGN (Institut National de l'Information Géographique et forestière) Saint Mandé France
IMBE (Institut Méditerranéen de Biodiversité et d'Ecologie) Marseille France
INRA (Institut national de la Recherche agronomique) Paris France
INRH (Institut National de Recherche Halieutique) Casablanca Morocco
INRIA (Institut National de recherche dédié au numérique) Le Chesnay France
Institut Agronomique et Vétérinaire Hassan II Rabat Morocco
Institute of Ecology and Earth Science, University of Tartu Tartu Estonia
Institute of Ecology, Tallinn University Tallinn Estonia
Institute of Governance for Sustainability, Tongji University Shanghai China
Institute of Spatial and Regional Planning, Universität Stuttgart Stuttgart Germany
Instituto de Geociencias (CSIC-UCM) Madrid Spain
International Social Science Council Paris France
IPEV (Institut Polaire français Paul-Emile Victor) Plouzane France
IRD (Institut de Recherche pour le Développement) Marseille France
IRSTEA (Institut de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture) Antony France
JPI Climate Brussels Belgium
Kasetsart University Bangkok Thailand
King Mongkut's University of Technology Thonburi Bangkok Thailand
Lab on International Law and Regulation, University of California San Diego United-States
Laboratoire Pierre Pagney: Climat, Eau, Ecosystèmes et Développement (LACEEDE) Université de Parakou Cotonou Benin
LNE (Laboratoire National de Météorologie et d'Essais) Paris France
Mahidol University Nakhon Pathom Thailand
Mediterranean Institute of Oceanography
Marseille France
Météo-France Saint-Mandé France
Ministry of Health at Michoacan State Morelia Mexico
Mountain Research Institute, University of Bern Bern Switzerland
National Center for Public Health and Analyses Sofia Bulgaria
Oeschger Centre for Climate Change Research, University of Bern Bern Switzerland
ONEMA (Office National de L'eau et des Milieux Aquatiques) Vincennes France
ONERC (Observatoire National sur les Effets du Réchauffement Climatique) Paris France
Oslo University Oslo Norway
Pacific Institute for Climate Solutions, University of Victoria Victoria Canada
PAGES (Past Global Changes) Bern Switzerland
PFE (Partenariat Français pour l’Eau) Nanterre France
PIK (Potsdam Institute for Climate Impact Research) Potsdam Germany
Plymouth Marine Laboratory Plymouth United-Kingdom
Prince of Songkhla University
Songkhla Thailand
Research Council of Lithuania Vilnius Lithuania
School of Environmental Sciences, University of Liverpool Liverpool United-Kingdom
SEARCA (Southeast Asian Regional Center for Graduate Study and Research in Agriculture) Laguna Philippines
Sir Arthur Lewis Institute for Social and Economic Studies, The University of the West Indies St Augustine Trinidad&Tobago
SMHI (Swedish Meteolorogical and Hydrological Institute) Norrkoping Sweden
The Coastal and Marine Union Leiden The Netherlands
Ubon Ratchathani University Ubon Ratchathani Thailand
UCL (University College London) London United-Kingdom
UNIMAS (Universiti Malaysia Sarawak) Sarawak Malaysia
Université de La Réunion Saint-Denis France
Université Paris Saclay Paris France
University College Cork Cork Ireland
University of Aberdeen Aberdeen Scotland
University of Dhaka Dhaka Bangladesh
University of Galway Dublin Ireland
University of Gothenburg Gothenburg Sweden
University of Guyana Georgetown Guyana
University of Kolkata Calcutta India
University of Leeds Leeds
University of Pécs Pécs Hungary
University of Tehran Tehran Iran
UPMC (Université Pierre et Marie Curie) Paris France
Young Academy of Japan
Tokyo Japan
YSN-ASM (Young Scientists Network-Academy of Sciences Malaysia) Kuala Lumpur Malaysia