Our Common Future Under Climate Change

International Scientific Conference 7-10 JULY 2015 Paris, France


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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

Sign the Statement !

The Our Common Future under Climate Change conference represents an historic opportunity to deliver a clear message to the Paris COP in December.

We warmly invite scientific institutions and international research programs to add their signature to this Statement. If your institution/international research program wish to support it, please return this letter to conference@commonfuture-paris2015.org before December 17, 2015

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