The world is worried about upcoming UN climate change negotiations in Cancun. Many experts doubt the UN has what it takes to address the greatest threat to humanity we have ever faced. They see the talks as a lost cause, a forum unsuited to overcoming the global challenge of climate change. The doubters are right to worry. But they are wrong to think we cannot make faster progress. Indeed, there is an urgent need to help those most affected by environmental changes. That is why I am going to Cancun: to remind world leaders that a growing global movement is calling for more ethical and enlightened approaches. We’re calling for climate justice. Climate change is not only a problem for the future, it is happening now. The impacts are already harming people around the world. Those bearing the brunt are most likely to suffer already from hunger, poverty, sickness and injustice. Women often face the harshest impacts. For decades, civil society organizations like Oxfam have fought to make a difference in the lives of nearly one billion people who go to bed hungry every night. We have worked tirelessly to help people climb out of poverty and grab onto hope. But climate change can wipe out development gains in a flash. 2010 has been a harsh reminder of the threat of extreme weather events like droughts and floods, which scientists predict will become more frequent and more severe as a result of climate change. Some of these impacts are being felt in the most insecure regions in the world, where poverty and instability threaten us all. Pakistan provides an example. This year millions of Pakistanis have been pushed to the brink as floods have ravaged the countryside and wiped out food and water supplies. The world’s humanitarian response has been stretched thin as more disasters have struck around the globe with frightening results. Climate change is a global problem in need of a global solution. Those most often excluded from global decision-making – women, indigenous people, poor communities and vulnerable countries– have knowledge the world needs to find solutions. The UN is still the best way to ensure their vital participation. A commitment to seeing the talks through is essential because only through binding negotiations can we be sure that those experiencing the most savage impacts have a seat at the table. Negotiations are frustratingly slow and the level of ambition among states appears dangerously low. But in spite of the major obstacles, recent talks have made real progress to lay the groundwork for broader agreement. None of the alternatives, such as the Major Emitters Forum, which excludes poor and vulnerable countries, have a comparable track record to the UN in terms of concrete decisions made. In Cancun there is an opportunity to find common ground on the establishment of a global climate fund that would help poor people protect themselves from the growing threats of a changing climate. It must be a new type of fund – which guarantees adequate support for poor communities to build resilience, and gives poor countries and women a strong voice in how it is set up and managed. This will help unlock the talks and build critical trust between poor countries and the developed world. Most crucially, a fund that is fair will ensure that vital resources are channeled effectively without waste or abuse to those who need support most and can use it best. Influential private investors have stressed that investment in less carbon-intensive energy systems will only flow at the scale and speed needed if it is supported by clear, credible and long-term policy frameworks. For those investments to reach the most vulnerable in the form of irrigation systems and flood preparation that builds resilience, governments must agree on how to raise public funds. A recent UN report produced by a panel of leaders and financial experts from around the globe, showed the cash needed to finance a global climate fund can be raised without burdening taxpayers or diverting resources already promised as badly needed development aid. A levy on uncapped emissions from international shipping and aviation, or a tax on financial transactions, could raise billions in new resources and help leverage the investments of the private sector. There is no longer an excuse for political leaders to shy away from the policies and commitments to climate funding and investment. Mobilizing the money needed to build resilience and a more sustainable energy future is possible. World leaders must now come to an agreement to make it happen. Success in Cancun can provide the foundation for achieving a global climate deal that pulls us back from the brink – a deal for climate justice. For that reason alone, I’ll be there. Mary Robinson is the Honorary President of Oxfam International, former President of Ireland, and recently launched the Mary Robinson Foundation – Climate Justice.