By Christiana Figueres and Joseph Alcamo
Over the past 12 months the number of countries signaling support for a long term vision on climate change has risen dramatically - this is an exciting development indeed.
Many now recognize that our best bet for a stable, healthy world is setting in train the policies and the actions to achieve what some term 'net zero' and others coin 'climate neutrality' in the second half of the century.
The G7 group of nations is a case in point. Meeting a few weeks ago, they underlined their commitment to de-carbonize the global economy over time--along with financing for developing country ambitions - both are pre-requisites for delivering and arriving at that long-term, safe haven.
A rapidly growing numbers of cities, regions and companies are sharing a similar ambition. Some have set long-term targets ranging from 100 per cent renewable energy by 2050 to absolute emission reductions, in some cases as high as 80 per cent.
There may be those wondering why so many nations, local authorities and companies are coming behind this vision and this aim--is it grounded in a populist campaign or romantic idealism? No, the foundation is science.
Governments have committed to keep a global temperature rise under 2 degrees C this century.
Over the last months several important reports from the scientific community--the "Structured Expert Dialogue" Report to the UNFCCC, the 5th assessment of the Intergovernmental Panel on Climate Change (IPCC), and the UN Environment Programme's Gap Report-- have delivered the several, key supporting messages:
• That the two degree temperature limit that is guiding international action represents an achievable "safe defensive line" against the worst, expected climate impacts--recognizing that many countries are calling for a 1.5 degrees C as an even safer defense line
• That postponing emission reductions will lead to higher costs and greater risks to society
• That global emission milestones can be reached by boosting energy efficiency, expanding the use of renewable energy, and adopting sustainable agriculture
These crucial facts need to be in sharp focus this week as leading scientists gather in Paris for the Our Common Future under Climate Change conference.
In order to realize a convincing new universal climate agreement this December the world needs patient, committed and creative negotiators and strong, focused political direction from ministers and heads of state.
But scientists have a pivotal role too--their support for a long term vision provides the rationale for action that can unlock a myriad of social, economic, and environmental benefits including potentially millions of new, quality jobs.
In defining where the world needs to be now, over the medium and into the long term scientists can provide the courage and the reason for ever more governments, cities and companies to align their policies and actions accordingly.
It is a time for scientists, the custodians of knowledge about climate change and its impacts, to roll up their sleeves to make the realities of climate change clear to the people in their countries.
From writing commentaries in their national newspapers, speaking to the media and engaging with their communities, scientists can be ambassadors for positive change.
There will be many key litmus tests from which citizens will be able to judge the success of new Paris agreement.
These range from a clear signal of financial support for developing nations to a mechanism that will trigger a regular review of how countries are doing and a ratcheting up of ambition over time.
A clear commitment to century-long action and a vision of a climate neutral world will be important for building confidence that governments are committed to a better managed, more stable and prosperous world.
Some may argue that today's ministers and heads of state having nothing to lose in signing up to a future that is far beyond their political terms.
But the signal it sends into the marketplace and to investors will speak volumes for generations to come.
It spells out long-term support for ever greener forms of energy generation; cleaner more livable cities; less polluting, ever more resource-efficient goods and services, and smarter management of the Earth's natural infrastructure from forests to rivers, soils and coral reefs.
Scientists have many key roles to play--helping society to understand the risks we are running from uncontrolled climate change to improving and discovering the transformational technologies needed for the transition to an ever greener economy.
They also have a role in exploring pathways to the future the world wants and needs, in order to better inform world-wide action.
With now just five months to go to finalizing the Paris agreement, it is time to put all the key foundations fairly and squarely on the table.
If researchers believe a good agreement needs a long term lens, then it is time for the scientists to make that clear--this week's conference affords the scientific community that opportunity on behalf of the Common Future of peoples everywhere.
Christiana Figueres is the Executive Secretary of the UN Framework Convention on Climate Change (UNFCCC). Joseph Alcamo is the Director of the Center for Environmental Systems Research, University of Kassel, Germany.