This article was first published in the New Statesman.

The impacts of climate change are disrupting the natural, economic and social systems we depend on. We are witnessing the effects: food shortages; energy insecurity; fires, floods, droughts, hurricanes. The cost of the climate crisis is being felt harder, wider and sooner than previously believed possible. However, though the situation may seem intractable, we must be united in our resolve to act.

In September I met farmers in eastern Uganda who, through the restoration and management of wetlands, are both protecting a natural buffer against flooding and erosion, and reducing food insecurity by supporting fisheries, agriculture and livestock. This kind of collaborative effort gives me hope that communities can become more resilient to climate-related threats when given support.

I am motivated by the bravery of young activists around the world speaking with fierce clarity about the need for urgent climate justice. Where do they find the strength to act so boldly? They say they find it in one another. I also have deep respect for indigenous peoples, standing in solidarity not only with each other but with the nature we must protect to have any chance of a liveable future.

Where the courage to act has been lacking is with those in power. The Elders, the group of independent global leaders founded by Nelson Mandela of which I am chair, are calling on governments ahead of COP27 to ensure their commitments match the mettle of those living with the pain wrought by the climate crisis. Declarations of intent are not good enough; those who hold power must be held accountable for their action, and inaction.

The Elders urge governments to act now with ambitious, credible and concrete transition plans. Leaders must deliver on climate finance promises, including the doubling of climate adaptation funds by 2025. They must go beyond platitudes and ensure funding starts to flow. They must enable an inclusive COP27 in Egypt, where the experiences and perspectives of civil society, young people, climate-vulnerable countries and indigenous communities are centre stage.

Power is not a right. It must be representative of all people and used honestly and accountably. It is the responsibility of each of us to demand this from our leaders. Never has there been a challenge in human history like the climate crisis, one where we must act together not just for ourselves, or just for our nation, but for all humanity.