You don't have to take my word for that. Mexican Foreign Minister Patricia Espinosa explicitly said at a meeting with the European Union (EU) on the last day of negotiations that without the constructive work of Europe it would have been impossible to bring the process back on track. A key reason why Europe has been able to make its mark on the agreement and help strengthen its ambition is that in Cancun, we managed to collaborate constructively and communicate in a clear and coordinated manner.

It has long been said that Europe must speak with one voice, but there cannot be only one voice. Rather, we should decide on the messages together and then communicate them clearly and consistently to the outside world. That's what we did in Cancun. And that's what we should be doing in the future to ensure that Europe's word has an influence worthy of the world's largest economy.

Cancun did not solve everything. The reduction commitments are not enough to keep the temperature increase below 2 degrees. There are other outstanding issues, too, such as the legal form of the agreement and how to provide the long-term finance. But Cancun proved that the multilateral process could deliver results. Without an agreement the UN process would have been in imminent danger.

Politicians and the public may have lost faith in the process and discarded it - with nothing to put in its place. Now we have a deal. But there is still much work ahead of us. Both internationally, where we must still deal with the outstanding issues, and domestically where we now have to deliver on what has been decided. In Europe we are already working on it.

Next year we present a road map for how we can create an intelligent, innovative low-carbon economy by 2050. We do this for the environment, but we also do it for the sake of competitiveness and energy security. In a world with ever more people and fewer fossil energy resources, it goes without saying that the winners will be the ones who are independent of oscillating oil prices, and who can provide energy efficient and innovative solutions.

If there is a task that the EU should take time to address, it is the task of getting energy security, economic growth and climate conservation to work in unison. The very core of our community is to take on the challenges together, with which EU member states cannot deal on their own. That's why it was so encouraging that the EU acted in a constructive and coordinated way in Cancun, and that's why the agreement in Cancun is a victory. Not only for the skillful Mexican presidency and for the multilateral process, but certainly also for Europe.

The author is European commissioner for climate action.