It is Time to Act: 2 Degrees is the Limit

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It is Time to Act: 2 Degrees is the Limit

Message on Climate Change to World Leaders

Human-induced climate change is an issue beyond politics. It transcends parties, nations, and even generations. For the first time in human history, the very health of the planet, and therefore the bases for future economic development, the end of poverty, and human wellbeing, are in the balance. If we were facing an imminent threat from beyond Earth, there is no doubt that humanity would immediately unite in common cause. The fact that the threat comes from within – indeed from ourselves – and that it develops over an extended period of time does not alter the urgency of cooperation and decisive action.

The world has agreed to limit the mean temperature increase to less than 2-degrees Centigrade (2°C). Even a 2°C increase will carry us to dangerous and unprecedented conditions not seen on Earth during the entire period of human civilization. Various physical feedbacks – in the Arctic, the oceans, the rainforests, and the tundra – could multiply a 2°C temperature increase into vastly higher temperatures and climate disruption. For this reason many scientists and some countries advocate for 1.5°C or even stricter targets.

To give up on the 2°C limit, on the other hand, would be reckless and foolish. We would abandon our remaining chance to stay within a safe operating space for humanity and that of millions of other species. By holding the 2°C limit, we would retain the global option to adopt an even more stringent emission reduction limit in line with evolving scientific knowledge and technological capacities.

The 2°C limit, or an even stronger target, can be met through long-term national strategies and concerted global cooperation. All countries must commit to a deep decarbonization of their energy systems, shifting from high-carbon energy (coal, oil, and natural gas) to low-carbon energy of various kinds (e.g. wind, solar, nuclear, carbon capture and sequestration, known as CCS). Low-carbon electricity plus massive gains in energy efficiency and the electrification of vehicles, heating and cooling systems of commercial as well as residential buildings can lead to a dramatic reduction of carbon-dioxide emissions alongside a growing economy. Changes in lifestyle patterns and urban planning can make another important contribution. The many co-benefits of decarbonization with the deployment of sustainable energy, information and communication technologies will include cleaner air and water, enhanced biodiversity, and security of domestic renewable energy resources. Targeted efforts are also required to decarbonize key industries. Finally, countries need to curb greenhouse gas emissions resulting from agriculture, livestock, and land-use change, such as deforestation. They must also manage and restore ecosystems to ensure they can serve as a significant net sink for greenhouse gas emissions.

The technological transition during the first half of the 21st century is within reach, especially in light of massive advances in knowhow in recent years. In many parts of the world and in some contexts, solar and wind power are already at “grid parity.” Large-scale deployment of electric vehicles, carbon-capture and sequestration, next-generation nuclear power plants for those countries deploying nuclear power, and other low-carbon energy technologies are all within reach. They can be pushed to commercial readiness and large-scale deployment through concerted public and private programs of research, development, demonstration, and diffusion (RDD&D) on a global scale.

We have nearly exhausted the Earth’s carbon budget, which measures the cumulative emissions of CO2 that will likely keep the planet within the 2°C limit.  Only through a drastic reduction of carbon emissions between now and 2050, en route to a zero-net emission economy in the second half of the century, can we meet the challenge of remaining below 2°C. Yet, deep decarbonization can be accomplished.  As President John F. Kennedy said a half-century ago, “We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills …”

In our time, humanity again must choose, this time to save our planet from shortsightedness, greed, and apathy to avoid catastrophic climate change. This time too, we must organize and measure the best of our energies and skills to stay within 2°C. We call upon you, world leaders, to recognize the gravity of the situation, and to call upon all of us to rise to the occasion. We owe nothing less to ourselves, to future generations, and to Earth itself.

Founding Signatories:

(* denotes members of the SDSN Leadership Council)

Irene Agyepong, Regional Director, Health for Greater Accra*

Belay Begashaw, Director, Columbia Global Center, Nairobi*

Frances Beinecke, President, Natural Resources Defense Council (NRDC)*

Joseph Bell, Hogan Lovells, Washington*

David Berry, Founder, Joule Unlimited*

Joshua Castellino, Dean, Law School, University of Middlesex*

Madhav Chavan, Co-founder and CE-President, Pratham, India*

Sir Partha Dasgupta, Professor Emeritus, University of Cambridge, United Kingdom

Bineta Diop, President, Femmes Africa Solidarité*

Achim Dobermann, Director, Rothamsted Research*

José María Figueres, CEO, Carbon War Room*

Maria Freire, President and Executive Director, Foundation for the National Institutes of Health (FNIH)*

Michael Gerrard, Professor, Columbia University Law School

Jennifer Gross, Member of the Board, Gross Family Foundation

Zakri Abdul Hamid, Chair, International Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)*

James Hansen, Former Director, NASA Goddard Institute for Space Studies*

Tom Heller, Executive Director, Climate Policy Initiative*

Pavel  Kabat, Director, International Institute for Applied Systems Analysis (IIASA)*

Joan  Kaufman, Director, Columbia Global Centers East Asia

Geoffrey Kent, Founder, Chairman and CEO, Abercrombie & Kent Group of Companies*

Niclas Kjellström-Matseke, Managing Director, Novamedia Swedish Postcode Lottery*

Israel Klabin, Founder and Executive Director, Brazilian Foundation for Sustainable Development*

Felipe Larraín, Director, Centro Latinoamericano de Políticas Económicas y Sociales (CLAPES-UC)*

Richard Layard, Director. Well-Being Programme Centre for Economic Performance London School of Economics*

Frannie Léautier, Partner and Chief Executive Officer, Mkoba Private Equity Fund*

Yuan Lee, Former President, Academia Sinica and Nobel Prize Laureate*

Klaus Leisinger, President, Stiftung Globale Werte Allianz*

Gordon Liu, Director, Peking University China Center for Health Economic Research (CCHER)*

Jane Lubchenco, Oregon State University, Corvallis*

Arun Majumdar, Energy Initiatives Lead, Google Inc*

Michael Mann, Professor and Director of the Earth System Science Center, Pennsylvania State University

Julia Marton-Lefèvre, Director General, IUCN*

Dirk Messner, Director, German Development Institute

Shahid Naeem, Director, Earth Institute Center for Environmental Sustainability*

Claude Nahon, Executive Vice President for Sustainable Development, EDF*

Rebecca Nelson, Professor, Cornell University*

Cherie Nursalim, Executive Director, GITI Group*

Ikenna Onyido, Founder and Director, Centre for Sustainable Development, Nnamdi Azikiwe University, Nigeria*

Mari Pangestu, Minister of Tourism and Creative Industries, Indonesia*

George Papandreou, Former Prime Minister, Greece*

V (Ram) Ramanathan, Professor, SCRIPPS Institution of Oceanography, UCSD, California

Srinath Reddy, President and Executive Director, Public Health Foundation of India*

Irwin Redlener, Director, National Center for Disaster Preparedness, Earth Institute, Columbia University

Aromar Revi, Director, Indian Institute for Human Settlements*

Angelo Riccaboni, Rector, University of Siena, Italy*

Johan Rockström, Executive Director, Stockholm Resilience Center*

Cynthia Rosenzweig, Professor, Earth Institute, Columbia University*

Jeffrey D. Sachs, Director, Earth Institute, Columbia University Director of the SDSN*

Hans Joachim Schellnhuber, Director, Potsdam Institute for Climate Impact Research (PIK)

Josette Sheeran, President, Asia Society*

Will Steffen, Adjunct Professor, Fenner School of Environment and Society, The Australian University

Lord Nicholas Stern, IG Patel Professor, Chair of Grantham Institute, London School of Economics

Pavan Sukhdev, Founder and Chief Executive Officer, GIST Advisory*

Jatna Supriatna, Chairman, University of Indonesia Research Center of Climate Change

John Thwaites, Chair, Monash Sustainability Institute*

Lena Trenschow-Torell, Chairman, MISTRA*

Laurence Tubiana, Professor, Sciences Po (Paris) and Columbia University, Co-Chair of the SDSN Leadership Council*

Ted Turner, Chairman, Turner Foundation, Inc. and Turner Enterprises Inc.*

Hans Vestberg, President and CEO, Ericsson Group*

Virgilio Viana, Director General, Amazonas Sustainability Foundation*

Martin Visbeck, Chair in Physical Oceanography, GEOMAR – Helmholtz Centre for Ocean Research Kiel & Kiel University*

Robert Watson, former Chair of the IPCC

E.O. Wilson, Emeritus, Harvard University

Xue Lan, Professor and Dean, School of Public Policy and Management, Tsinghua University, Co-Chair of the SDSN Leadership Council*

Hirokazu Yoshikawa, Professor, New York University*

Soogil Young, Professor, KDI School of Public Policy and Management*

Hania Zlotnik, Former Director, UN Population Division*


To be added

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