From Huffington Post: http://www.huffingtonpost.com/paul-polman/un-climate-talks_b_4177721.html
In September, the Intergovernmental Panel on Climate Change published the first part of its review of the latest climate science, the AR5 report. What makes the IPCC unique is that it is not the voice of a single scientist, or even that of a group. It represents a combined view of in this case 209 lead authors and a further 600 contributing authors. That is 809 scientists from all around the world, calmly setting out the data as they observe it. They observe that since the 1950s, many of the changes to our climate are unprecedented over the previous decades and in some cases millennia. They observe that the atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased. They observe that each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. In the Northern Hemisphere, 1983-2012 was likely the warmest 30-year period of the last 1400 years. Just after the report came out many business leaders urged immediate action from governments, businesses and society to reduce carbon emissions and increase resilience. They were right to do so.
Climate change is sometimes misunderstood as being about changes in the weather. In reality it is about changes in our very way of life. Climatic shifts on the scale suggested by our current emissions trajectory could wreak havoc with the global agricultural system. 2 degrees of average warming could still mean several times that in the world’s temperate regions, where much of the world’s food is grown. Changing patterns of rainfall could increase the volatility of global crop yields as more countries experience doubts and floods that can wipe out whole harvests in the blink of an eye. All this during a period in which we expect the world to welcome an additional 2 billion people. The arithmetic doesn’t add up. The gains in prosperity that many in the world have enjoyed over the past century of growth and industrialization could be severely curtailed if we do not change path urgently towards a more sustainable future. That is to say nothing of the more devastating effects of rising sea levels on the millions of people who live in low lying coastal regions and the prospect of hundreds of millions of environmental refugees that may be created if we do not act now.
Governments’ ambitions to limit warming to 2°C now appear increasingly more difficult: in 2012 PWC estimated that the required improvement in global carbon intensity to meet a 2°C warming target had risen to 5.1% a year from now to 2050 – a rate of decarbonization not achieved since World War Two. But every year of delay will increase emissions, lock the economy into a high carbon future and make future emissions reductions more costly. The world must therefore act in a swift and coordinated way to avoid the more pessimistic scenarios of 4°C or even 6 °C average warming above pre industrial levels.
But faced with all this we have no choice but to be optimistic. It is often when most challenged that the human species can surprise us most. As we head towards the UN climate negotiations (UNFCCC COP19) that kick off on 11 November in Warsaw we have to focus on three things; Understating what is possible, showing what is possible and doing what is possible.
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