The United Nations Climate Convention meeting in Warsaw, Poland, comes with less than two years to go for governments to deliver on their promise of a universal new agreement by 2015 - this is the time for ambition rather than caution to define the international climate negotiations.
We have in some ways been here before: the Copenhagen UN climate conference was also scheduled to deliver a profound and game-changing deal.
Is there any evidence that where 2009 in the end fell short, 2015 will propel the world into a new era of climate diplomacy and universal cooperation that is able to lift the threat of dangerous global warming from the lives of billions of people? The answer must be a qualified yes.
Perhaps the most powerful symbol of positive change is the continued, remarkable growth in renewable and clean energies which are building the confidence among nations that a transition to a low-carbon, resource-efficient inclusive Green Economy is decidedly doable.
The latest assessment by the Frankfurt School -UNEP Collaborating Centre for Climate &Sustainable Energy Finance - and Bloomberg New Energy Finance shows that in 2012 total renewable energy power capacity worldwide exceeded 1,470gigawatts (GW), up 8.5 per cent from 2011.
Indeed since 2006 investments worth US$1.3 trillion have been made in the clean energy sector and over the past eight years the number of countries with clean energy targets nearly tripled from 48 to close to 140 - half of which are developing countries.
When renewable energy technologies first moved from the lab to the marketplace, the refrain by many was that they would not work and then when this was proven false that they would be too costly. Finally critics suggested that renewables would be small-scale incapable of being taken to scale-recent years have seen each of these criticisms comprehensively and systematically demolished.
A new report from Deutsche Bank says that, fore xample, solar PV is about to enter a "third growth phase" where it can be deployed without subsidies. Indeed, the analysts suggest that three-quarters of the world's market will be "sustainable" for solar within 18 months, meaning they can operate with little or no subsidy.
In 2012 a country like Germany generated half its electricity from wind, solar and other renewable energies second only to Spain, which in April that year generated over 60 per cent from renewable sources.
And it is happening in developing countries too. Insupport of the Warsaw meeting UNEP has produced a short publication called the Clean Energy Voyage. It cites the African country of Cape Verde which this year made the decision to be 100 per cent renewable by 2020.
Cape Verde's green energy revolution began in 2010 with the construction of two solar parks and the Cabeolica wind farm project - a large scale public-private partnership. It, along with many other countries and communities, is demonstrating the inordinate opportunity of rural electrification without waiting for the grid. In 2012 a village on the country's Monte Trigo island enjoyed for the first time 24-hour electricity as a result of an off-grid solar project.
Mongolia, the host of World Environment Day 2013, has inaugurated its first wind farm with plans to develop an Asian super grid for clean energy with partners such as Japan. However you look at renewable energy, it has consistently performed well beyond even the most optimistic estimates. In the year 2000, the International Energy Agency estimated that by 2010 34 GW of wind would have been installed and the World Bank estimated that China would have 9GW of wind and half a GW ofsolar by 2020.
The reality was that in 2010, 200 GW of wind was operating world-wide and China had 62GW of windand 3GW of solar by 2011.
Secondly, the political landscape is thawing. In June this year the heads of state of China and the United States agreed to a series of anti-climate change measures including action to bring down the use of synthetic chemicals known collectively as HFCs. Their announcement was subsequently endorsed by the G20 group of leaders meeting in St Petersburg.
Meanwhile key players are signaling their determination to shift the landscape away from fossil fuels. Christina Lagarde, the head of the International Monetary Fund has this year underlined the role of her organisation in moving towards a low-carbon global economy.
She has singled out fossil fuel subsidies, estimate dby the IMF as amounting to nearly US$2 trillion in 2011, or 2.5 per cent of the world's GDP, as lowhanging fruit. Recently the World Bank said it wouldonly fund coal-fired power stations in exceptionalcircumstances and the European Investment Bankhas voiced its support for clean energy and energy efficiency as priorities.
The Institutional Investors Group on Climate Change, which surveyed close to 40 asset owners with some US$14 trillion undermanagement, has found that many are now making investment decisions based on climate considerations. Furthermore both the science and the costs of inaction get ever more compelling.
The just released assessment of Working Group Iof the Intergovernmental Panel on Climate Change(IPCC) underlines high and increasing scientific confidence that humans are altering the climate with all the implications for extreme weather events, rising sea levels threatening coastal infrastructure, agriculture and food production and distribution and overcoming poverty.
According to a new report, climate change has already contributed to 400,000 deaths per year and over US$699 billion, 0.9 per cent annually, in loss to gross domestic product (GDP).
This is the finding of a new report - Climate Vulnerability Monitor: A Guide to the Cold Calculusof a Hot Planet - written by more than 50 scientists,economists and policy experts, and commissioned by 20 governments.
As nations gather in Warsaw, both the inordinate opportunity to fast track sustainable development and the huge risks economies run by inaction should be uppermost in everyone's mind.
2013 is the moment when governments, along with local authorities, development banks, the private sector and the UN need to do some serious homework that looks not to how little they can do to meet the realities of climate change.
Rather to signal real ambition by assessing how far they can go in catalysing emission reductions and adaptation strategies while liberating the necessary investments needed to decarbonise the global economy.
About the author
Achim Steiner is a United Nations Under-Secretary General and Executive Director of the UN Environment Programme (UNEP).
Before joining UNEP, Mr Steiner served as Director General of the International Union for Conservation of Nature (IUCN) and prior to that as Secretary Generalof the World Commission on Dams.
His professional career has included assignments with governmental, non-governmental and international organisations including in India, Pakistan, Germany, Zimbabwe, USA, Vietnam, South Africa, Switzerland and Kenya.