Ladies and Gentlemen, I could not be more pleased that you have been able to join today's meeting. Your deliberations on such critical issues could not be more important, nor more timely, and I must express my warmest gratitude to you all for making space in your busy schedules to be here at this meeting convened by my International Sustainability Unit and the World Health Organization.

I hardly need to tell you Ladies and Gentlemen we are faced, I fear as far as the problem of human-induced climate change is concerned with a challenge of astonishing complexity.  Its solution will be similarly complex and will require the participation and support of a very wide range of inter-disciplinary teams.  It is therefore suitably encouraging to see leaders here today from the worlds of acute medicine, public health and academia and, among others, the Royal Colleges, Public Health England, the Department of Health and the N.H.S. Sustainable Development Unit.  
The fact of climate change is now accepted by every major scientific body in the whole world.  The gravity and immediacy of the threat it poses to us and our children and grandchildren is also accepted by constituencies that can scarcely be accused of being part of some half-baked conspiracy dreamt up by extreme environmentalists intent on undermining capitalism these constituencies include the U.N., the World Bank; The Pentagon and the U.K. Ministry of Defence, the C.I.A., N.S.A. ... and, I'm happy to say, nurses and doctors!
I don't think you need me to tell you that Climate change will cause alterations to patterns of bacterial, toxic and vector-born disease.  Through extreme weather events, it is already causing ecosystem collapse, loss of habitation, poverty, starvation, migration and conflict.  Some five years ago, the Lancet’s Commission on Climate Change described it as ‘The greatest threat to human health of the 21st Century’ and this warning has been echoed worldwide by the American Medical Association, Academy of Paediatrics, College of Preventative Medicine and Public Health Association, the Australian Medical Association, the World Federation of Public Health Organizations and the World Health Organization.  Seven years ago, the U.K.'s Royal College of Physicians hosted a full day’s meeting on the Health Impacts of Climate Change.  Four years ago, its president co-authored an editorial with two senior military figures to ‘raise the alarm’.  I am delighted that the meeting which my I.S.U. hosted in December 2013 to help forge a consensus on the critical importance of the health sector speaking with a coherent voice on this issue has encouraged others to speak up and indeed loudly. I was, if I may say so, especially encouraged that the W.H.O. should have subsequently devoted so much time to Climate Change at its annual meeting last year and I'm very pleased that they are co-hosting this meeting today.
But you all know the reality that shouting for help is not the same as delivering it.  Recognizing life-threatening illness is not the same as taking life-saving action and, to use the medical model of Climate Change, if the planet were a patient, we would have intervened long ago. Not waited until we had tested the disease to the patient's destruction. Such action, to be effective, requires not only an inter-disciplinary but also a cross-disciplinary approach!  Your voice is a trusted one.  You can lead the opinions of the general public and of your members. 
And you have another advantage. Your message isn’t just of alarm, but of hope.  Actions which are good for the planet are also good for human health: taking a more active approach to transport by walking and cycling and adopting healthy diets reduce greenhouse gas emissions, but also reduce rates of obesity, heart disease, cancer and more saving lives and money.  Reductions in air pollution also result with separate and additional benefits to human health.  A healthy planet and healthy people are two sides of the same coin.
The Intergovernmental C.O.P. 21 climate change negotiations that will take place in December provide perhaps our last opportunity to set targets that will keep the world to below two degrees of warming.  Should we miss this moment the chances of success are, I fear, vanishingly small.  We must ensure that there is a real willingness to act and that such actions are meaningful in quality and scale.  This will require strong messaging to all negotiating teams and to those with influence upon them, internationally.  If, and it is a big "if", we can muster agreement there, we can only pray that our sick planetary patient might be placed on a road to recovery, in the process bringing gains for human wellbeing.  Failure to write the prescription, however, might leave us contemplating the death certificate instead...
So, my fervent hope is that you can find the means to make the difference that our world so desperately needs.