Our world is on an unsustainable path that threatens not only our environment, but our economies and our security. It is time to launch a broad operational accord on climate change that will set us on a new course.

A successful agreement depends upon a number of core elements, but two are shaping up to be essential: first, that all major economies set forth strong national actions and resolve to implement them; and second, that they agree to a system that enables full transparency and creates confidence that national actions are in fact being implemented.

Transparency, in particular, is what will ensure that this agreement becomes operational, not just aspirational. We all need to take our share of responsibility, stand behind our commitments, and mean what we say in order for an international agreement to be credible.

Representatives from more than 190 countries have gathered in Copenhagen in the hopes of meeting this urgent challenge to our planet. If we are serious about that goal, we will all embrace these principles.