This is the text of a letter sent to Prime Minister Stephen Harper from the Canadian climate science leaders (see next post for signatories):

An Open Letter to the Prime Minister of Canada on Climate Change ScienceApril 18 2006The Right Honourable Stephen Harper, P.C., M.P.Prime Minister of CanadaOttawa, ON K1A 0A3Dear Prime Minister:As climate science leaders from the academic, public and private sectors across Canada, we wish to convey our views on the current state of knowledge of climate change and to call upon you to provide national leadership in addressing the issue.  The scientific views we express are shared by the vast majority of the national and international climate science community.We concur with the climate science assessment of the Intergovernmental Panel on Climate Change (IPCC) in 2001, which has also been supported by the Royal Society of Canada and the national academies of science of all G-8 countries, as well as those of China, India and Brazil. We endorse the conclusions of the IPCC assessment that “There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities” and of the 2005 Arctic Climate Impact Assessment that “Arctic temperatures have risen at almost twice the rate of those in the rest of the world over the past few decades”. Climate variability and change is a global issue and the international IPCC process for assessment of climate science, with its rigorous scientific peer review processes, is the appropriate mechanism for assessing what is known and not known about climate science.  Many Canadian climate scientists are participating in the preparation of the IPCC Fourth Assessment Report which will be completed in 2007.  The following points emerge from the assessments and ongoing research by respected Canadian and international researchers:

• There is increasingly unambiguous evidence of changing climate in Canada and around the world.
• There will be increasing impacts of climate change on Canada’s natural ecosystems and on our socio-economic activities.
• Advances in climate science since the 2001 IPCC Assessment have provided more evidence supporting the need for action and development of a strategy for adaptation to projected changes. 
• Canada needs a national climate change strategy with continued investments in research to track the rate and nature of changes, understand what is happening, to refine projections of changes induced by anthropogenic release of greenhouse gases and to analyse opportunities and threats presented by these changes.

We have supplied justification and more detail for each of these points in the accompanying documentation.We urge you and your government to develop an effective national strategy to deal with the many important aspects of climate that will affect both Canada and the rest of the world in the near future. We believe that sound policy requires good scientific input.We would be pleased to provide a scientific briefing and further support, clarification and information at any time.Yours sincerely:Signed by 90 Canadian climate science leaders from the academic, public and private sectors across the country

Cc: Honourable Rona Ambrose, Minister of the Environment, Honourable Gary Lunn, Minister of Natural Resources and Honourable Loyola Hearn, Minister of Fisheries and Oceans

Canadian Climate Science Leaders