Climate change is the most serious threat the world faces. That’s why this December, representatives from 195 countries will meet at a United Nations conference in Paris to reacha new international climate agreement.

The question is: How do we make sure it’s an effective one?

For nearly two years,ACT 2015, a consortium of the world’s top climate experts, has conductedin-depth researchand engaged with key stakeholders around the world to explore the core elements of the global agreement. In this new video, we describe three ingredients to make sure that the new international climate agreement spurs greater climate action.

To be a success, the climate agreement must do three things:

  1. Setlong-term goals for mitigation and adaptationto help the world cope with climate impacts and phase out greenhouse gas emissions as early as possible in the second half of the century.
  2. Ensure countries aretransparent and accountable for their climate action commitments, through a process that regularly evaluates their progress.
  3. Put in place a process forcountries to regularly increase their climate efforts on mitigation and adaptation, along with scaled up finance, capacity building and technology transfer, in a timely way—at least onceevery five years starting in 2020.

Increasing these efforts every five years is vital, not only because the world can’t wait longer for countries to come back to the table and ramp-up their action, but also because this is the least expensive and most fair path to take,according to the latest research. It’s also essential because we need to increase our efforts to prevent and tackle the serious damage that many of the most vulnerable communities are already facing around the world.

The good news is that the world is already taking steps toward a low-carbon and climate resilient economy. An unprecedented number of countries submitted theirnational plansto deal with climate change – not only the world’s largest counties, but also those counties that have contributed the least to the problem but face the most severe impacts. Investments in renewable wind and solar energy are on the rise, major corporations are aligning theirbusiness practices with climate science, religious leaders are calling for actionbased on moral responsibility, and cities across the globe are taking measures to make urban life more sustainable.

But they alone are not yet enough to overcome the climate change challenge. Reachinga global climate agreement in Pariscan drive even more ambitious action in the years to come, and can send the signal to the world that the transition to a low-carbon and climate resilient society is here to stay. We are counting on our leaders to be bold andseize the opportunity, together, to build lasting economic growth while reducing the immense risk of climate change. Indeed, acting now is the only way to put us all on a path to a more prosperous and secure future.