The European Council meeting, and the following week's vote in the European Parliament, is crucial for the EU's possibility to influence the international negotiations in the run up to Copenhagen.

Of course there will be difficult negotiations, as different countries will push for more beneficial outcomes for themselves, and the economic crisis will be used as an excuse for less ambition. But at the end of the day we have to realize that we can't negotiate with nature. And at the same time, we need to address the root causes of our unsustainable way of living. We have to start taking sustainable development seriously.

Development cannot be sustainable unless it is equitable – and that means promoting human rights and democracy. It means respecting international and national commitments on gender equality and social justice. It means working for fairer world trade and remodelling our global financial systems so that they serve people rather than markets.

The challenges we face in terms of climate change, loss of biodiversity, unemployment, gender inequality, poverty and economic injustice are complex both in terms of their nature and of the solutions required. But the problems are interlinked, and their solutions therefore need to be mutually supportive.

We have the know-how, the tools and the technology to mitigate climate change and biodiversity loss. We have the means and the public support to fight poverty and social injustice. But as Albert Einstein once said: "We can't solve problems by using the same kind of thinking that created them."

We therefore need a new world order for financial flows and wealth distribution. And a new way of thinking on how we make the world a better place for generations to come.

We need to devise a new and comprehensive approach which strikes the right balance between environmental protection, economic growth and social progress, which contribute to our and our next comers' quality of life. It requires decoupling economic growth from environmental degradation. It requires social equity, gender equality and human rights to prevail greed and irresponsibility.

Europe to \"think big\"

The first step to take is for the meetings in Poznan and Brussels to give a clear message that the financial and economic situation is not an obstruction, but a catalyst for change.

That we now have the opportunity, through investments in energy efficiency, renewable energy and environmental technologies and services, to both create jobs and growth and help transforming the world into a low carbon economy.

The next step will be for Europe to "think big." We should not only push for an ambitious global climate agreement in Copenhagen, but at the same time redouble our efforts to successfully conclude the WTO Doha Round and to reach the UN Millennium Goals. And we need to promote a new financial/economic world order built on equity, democracy, transparency and accountability.

Ultimately, sustainable development should be the overriding principle of the EU. Not only in words, but by concrete actions.

In an article on EUobserver.com (28/11), Peter Sain ley Berry argues that the recession could in 20 years give birth to an EU Treaty of Sustainability. Over five years ago, it was my wish that we wouldn't have to wait for quite as long to make the EU's commitment to sustainable development truly operational.

Already in 2003, I suggested to add a Protocol on Sustainable Development to the draft Constitutional Treaty. The Protocol would have made sustainable development a legal requirement.

All major EU policy proposals and all legislative acts would have been preceded by a sustainability impact assessment and accompanied by a detailed statement demonstrating their compliance with sustainable development. And the Protocol European Court of Justice would have controlled its application.

If Europe is serious about responding to citizen's concerns and ensuring the responsible management of our common economy, environment and social welfare, the EU leaders need to implement and practice a true policy for sustainable development.

Let's hope that the European Council later this week will not concede to shortsighted own-interest. But bring the future and the rest of the world in the picture. Time has come to take decisive action for a truly sustainable development.

Margot Wallström is European Commission Vice-President