The Paris Climate Conference (COP21) opens tomorrow. After the tragic events of Friday the 13th of November, Paris and indeed the world seem like more fragile places.

The task—and opportunity—of COP21 is to show that this need not be the case; that dialogue and cooperation can allow the international community, painstakingly like but ultimately positively, to manage common problems, of which this world now seems more fraught.

Climate change is not just any problem. It risks multiplying others, from water stress to inequality; from conservation to national security; and from the loss of livelihoods to risks to international order.

More than 150 Heads of State and Government are confirmed to come to Paris for the opening of COP21 on Monday. This will be the largest gathering of world leaders outside the annual UN General Assembly (the largest was the 2009 Copenhagen climate summit). This is a testament to the international importance of climate change.

Each leader will give a speech, and many will meet bilaterally. In a world that seems at times riven with competition and indeed conflict, what message could leaders send and what is their role in COP21?

Above all, leaders should seize the opportunity of Paris to articulate an aspiration for a world of cooperation and dialogue. Climate change is not a zero sum issue: there are no winners from failure, and there are great benefits to collective action. On the other hand, failure to address climate change will gravely sharpen the already severe divisions over water, land, food, technology, and so on.

There is still much work to do in the negotiations to reach an agreement in Paris. The direction given by leaders in their speeches and bilateral meetings will be crucial to finding agreement on the crucial issues that remain unresolved. Their speeches will be scrutinized for signs of flexibility or entente on these issues; and, as with the US-China agreement on climate in 2014, the wording they chose may be source of inspiration for the text of the agreement itself.

Three issues in particular come to mind in this regard. The first relates to the affirmation of the 2°C objective, and above all its translation into a concrete global emissions target. Many emerging countries, in particular, are reluctant on this point, fearing that agreement on an emissions target may form the basis for a more directive approach to ‘burden sharing’. Thus, the global emissions goal will need to be combined, and it is here that politicians can play a role, with a political vision for an equitable transition to this objective. Countries will each need to take their own national pathways towards this global objective, taking into account differences in their level of development. The Paris Agreement should set a common objective, but also reassure countries that they will define their pathway there. An agreement that is fair must be based on this combination of common purpose and national commitment.

The final issue is adaptation and resilience. It is often argued that adaptation is a local issue. This is true. But it is also true that a lack of adaptive capacity at local or national level can rapidly lead to international implications—migration, food crises, security issues and so on. Leaders should recognise that ensuring that countries and the global economy are resilient must be an international priority of the highest order. Our scientific, economic and political institutions will need to respond to the implications of climate change, and this response is only just beginning. Leaders should take the opportunity to highlight this emerging agenda; as financial vulnerability has mobilised all governance institutions in the wake of the 2008 financial crisis, so must we prepare for climate vulnerability. Leaders could pledge significant new financing efforts for adaptation and resilience. This would help not only address the grave lack of adaptation financing, but also the political divide that exists on the issue of adaptation financing.

Leadership is the capacity to reimagine the future, to borrow from former Australian Prime Minister Paul Keating. The task for leaders in Paris is lay the basis of an agreement that will set out this vision for decades to come.