Forty of the world’s leading climate scientists have signed an open letter demanding global leaders take bolder action against climate change (see full list below).

The joint statement – initiated by WWF and endorsed by recognised climate luminaries such as Sir John Houghton, former chair of the Intergovernmental Panel on Climate Change (IPCC) – calls for industrialised countries to make a commitment, at the UN Climate summit in Copenhagen, to cut carbon emissions by at least 40% below 1990 levels by 2020.
 
Saleemul Huq, one of the signatories, IPCC author and Senior Fellow in the Climate Change Group at the International Institute for Environment and Development, said: “The scientific evidence now indicates that even a rise in temperature of 2°C will entail considerable hardships for poor and vulnerable people around the world, especially those living on low-lying islands and coasts.
 
“So a 40% reduction in emissions is the very least required to provide a better chance of avoiding devastation for these countries and communities.”
 
WWF’s Head of Climate Change, Keith Allott, says: “As the UK government rallies the EU to step up to the mark ahead of Copenhagen, it’s time for Gordon Brown and other world leaders to turn words into action.”
 
Dr Dave Reay, another of the signatories, IPCC contributor and Senior Lecturer in Carbon Management, Edinburgh University, said: "The scientific evidence of climate change from around the world is providing a clear and urgent call for action.
 
“If we are to be successful in preventing the worst impacts of climate change then world leaders from the industrialised nations must commit to reducing emissions by at least 40 per cent by 2020. The meeting in Copenhagen later this year is hugely important in putting the world on a path that leads us away from dangerous climate change."
 
The WWF say key meetings that will shape the global climate deal take place in coming weeks, including the UN General Assembly in New York and the G20 Heads of State meeting inPittsburgh.
 
Campaigners say it is vital that the politicians attending take note of such timely advice from the world’s scientific community.
 
The scientists’ statement on 40% emissions reduction target for developed countries follows…
 
Copenhagen climate targets must be more ambitious
At the UN Climate Conference in Copenhagen this December, world leaders have the opportunity to agree a historic global climate deal. To avoid dangerous climate change, the deal must be based on the most up-to-date scientific understanding of the emissions reductions required, with obligations divided equitably between developed and developing countries. This means that developed countries must reduce greenhouse gas emissions by at least 40% below 1990 levels by 2020.
 
Copenhagen represents our best chance to avert the worst impacts of climate change on people, species and ecosystems. More than 120 countries, including the members of the G8, the EU, and key emerging economies such as China, South Africa and Mexico, agree that the rise in global temperature must stay well below 2°C. Beyond this point climate impacts will be more severe, with the risk of crossing ‘tipping points’ with dangerous and irreversible effects.
 
To stand a good chance of achieving this goal, the last Intergovernmental Panel on Climate Change report (2007) recommended that developed countries should reduce emissions by 25-40% on 1990 levels by 2020. Yet more recent evidence shows that only reductions at the top end of this range will be sufficient to avoid the worst impacts of climate change.
 
Developed countries have so far committed to reduce greenhouse gas emissions by only 10-16% by 2020, a level dangerously inconsistent with their commitment to the 2°C target. The latest scientific evidence clearly shows that these countries must increase their ambition and reduce emissions by 40% by 2020 to maintain a credible ambition of avoiding dangerous climate change.
 
Signed in our personal capacity:

Dr Paulo Artaxo, Brazil
Lead author of IPCC 4th Assessment Report, Institute of Physics, University of Sao Paulo
 
Samar Attaher, Egypt
IPCC contributor and Climate Change Researcher, Ministry of Agriculture, Cairo
 
Prof Peter Barrett, New Zealand
Professor of Geology, Antarctic Research Centre, Victoria University
 
Dr Nancy Bertler, New Zealand
Leader of the New Zealand Ice Core Programme, Victoria University
 
Sophie des Clers, United Kingdom
IPCC corresponding author and Fisheries Geographer, University College London
 
Dr Valérie Masson-Delmotte, France
IPCC contributor, Paleoclimatologist and Head of Research at the "Laboratoire des sciences du climat et de l'environnement"
 
Prof John Harte, USA
Professor of Environmental Science, University of California
 
Prof Ove Hoegh-Guldberg, Australia
Director, Centre for Marine Studies, University of Queensland
 
Dr Lars R. Hole, Norway
Senior Scientist, Norwegian Meteorological Institute
 
Sir John Houghton, United Kingdom
Former Chair of Scientific Assessment, IPCC and Former Chief Executive, Met Office
 
Prof Lesley Hughes, Australia
IPCC Lead Author, Department of Biological Sciences, Macquarie University
 
Dr Saleemul Huq, United Kingdom
Lead Author, IPCC 3rd Assessment Report and Senior Fellow, Climate Change Group, International Institute for Environment and Development
 
Henry P. Huntington, USA
Lead Author, Arctic Climate Impacts Assessment
 
Prof Philippe Huybrechts, Belgium
IPCC contributor and Professor of Climatology and Glaciology, Vrije Universiteit Brussels
 
Jiang Kejun, China
Lead Author, IPCC Working Group III and Director of Energy System Analysis and Market
Analysis Division at the Energy Research Institute of National Development and Reform
Commission
 
Bernardus H.J. de Jong, Mexico
IPCC contributor, El Colegio de la Frontera Sur
 
Prof Rik Leemans, The Netherlands
Environmental Systems Analysis group, Wageningen University
 
Dr José Marengo, Brazil
IPCC Lead Author and Researcher at National Institute for Space Research
 
Prof Anthony J McMichael, Australia
Professor of Population Health, The Australian National University, and Honorary Professor of Climate Change and Human Health, University of Copenhagen
 
Dr. Charles K. Minns, Canada
Adjunct Professor, Ecology and Evolutionary Biology, University of Toronto, and Scientist
Emeritus, Fisheries and Oceans Canada
 
Prof Abhijit Mitra, India
Department of Marine Science, University of Calcutta
 
Dr Carlos Afonso Nobre, Brazil
IPCC Lead Author, Head of the Scientific Committee of the International Geosphere-Biosphere Program, Co-ordinator of the Centre for Earth System Science at the National Institute for Space Research and Executive Secretary of the Brazilian Network for Climate Change Research
 
Pan Jiahua, China
IPCC advisor to Working Group III and Executive Director of Research Centre for Sustainable
Development at the Chinese Academy of Social Sciences
 
Dr Barrie Pittock, Australia
IPCC Lead Author and Honorary Fellow, CSIRO Australia
 
Dr Dave Reay, Scotland
IPCC contributor and Senior Lecturer in Carbon Management, Edinburgh University
 
Andy Reisinger, New Zealand
Coordinator of IPCC Synthesis Report and Senior Research Fellow, Climate Change Research Institute, Victoria University, Wellington
 
Dr Suzana Kahn Ribeiro, Brazil
Vice-Chair of IPCC Working Group III and Coordinating Lead Author of IPCC 4th Assessment Report
 
Dr Luis Pinguelli Rosa, Brazil
Head of Brazilian Forum on Climate Change and Director at Alberto Luiz Coimbra Institute for Post-Graduation and Research in Engineering, Federal University of Rio de Janeiro
 
Antonio Ruiz de Elvira, Spain
Professor, Applied Physics, Universidad de Alcala, European Climate Forum
 
Dr Jim Salinger, New Zealand
Lead Author for IPCC 3rd and 4th Assessment Reports, Honorary Associate Professor, School of Environment, University of Auckland and President of the World Meteorological Society’s Commission for Agricultural Meteorology
 
Dr Roberto Schaeffer, Brazil
IPCC Lead Author and Researcher at Federal University of Rio de Janeiro
 
Dr Michael Schirmer, Germany
Climate Change Impact Research, University of Bremen
 
Bernard Seguin, France
IPCC contributor, Institut National de Recherche agronomique
 
Dr Vijai Pratap Singh, India
Program Manager (Climate Change), Leadership for Environment and Development India (LEAD India), New Delhi
 
Prof Peter Smith, Scotland
IPCC Lead Author and Convening Lead Author, and Royal Society-Wolfson Professor of Soils & Global Change, University of Aberdeen
 
Dr Armi Susandi, Indonesia
Vice Chair, IPCC Working Group on Adaptation, National Council on Climate Change, Indonesia, and Head of Department of Meteorology, Bandung Institute of Technology
 
Wang Yi, China
Deputy Director of the Institute of Policy and Management, Chinese Academy of Sciences
 
Dr Wong Poh Poh, Singapore
Lead Author, IPCC 3rd Assessment Report, Coordinating Lead Author, IPCC 4th Assessment Report, National University of Singapore
 
Dr Richard W. N. Yeboah, Ghana
Department of Agricultural Economics and Extension, University for Development Studies
 
Zhou Dadi, China
Senior Advisor and Researcher, Energy Research Institute of National Development and Reform Commission (NDRC)

Source: Press Release from the International Institute for Environment and Development