|Heavier rains, flooding and warmer temperatures around the globe are just some of climate change's effects [EPA]
Durban, South Africa - Before the Copenhagen Climate Change Summit two years ago, the two of us sat together in Cape Town to listen to five African farmers from different countries, four of whom were women, tell us how climate change was undermining their livelihoods. Each explained how floods and drought, and the lack of regular seasons to sow and reap, were outside their normal experience. Their fears are shared by subsistence farmers and indigenous people worldwide - the people bearing the brunt of climate shocks, though they played no part in causing them.
Now, two years later, we are in Durban, where South Africa is hosting this year's climate-change conference, COP-17, and the situation for poor people in Africa and elsewhere has deteriorated even further. In its latest report, the United Nations Intergovernmental Panel on Climate Change concludes that it is virtually certain that, in global terms, hot days have become hotter and occur more often; indeed, they have increased in frequency by a factor of 10 in most regions of the world.
Moreover, the brutal paradox of climate change is that heavy precipitation is occurring more often as well, increasing the risk of flooding. Since 2003, East Africa has had the eight warmest years on record, which is no doubt contributing to the severe famine that now afflicts 13 million people in the Horn of Africa.
These are the consequences that a mere one degree of warming above pre-industrial levels has wrought. The UN Environment Programme's just published report, Bridging the Emissions Gap, shows that over the course of this century, warming will likely rise to four degrees unless we take stronger action to cut emissions. Yet the latest evidence demonstrates that we are not acting - the International Energy Agency's World Energy Report 2011 reveals that CO2 emissions have rebounded to a record high.
We are alarmed that expectations for COP-17 are so low. Where is the global leadership that must respond urgently? We desperately need a global deal.
At the heart of this deal is the preservation of the Kyoto Protocol. The Protocol is not a perfect instrument. It does too little to cut global emissions, and it requires too few countries to cut their emissions growth. But it is part of international law, and that is vital.
"Climate change is a global problem: if countries are not confident that others are addressing it, they will not feel an imperative to act themselves."
Climate change is a global problem: if countries are not confident that others are addressing it, they will not feel an imperative to act themselves. So, having a legal framework with clear and common rules to which all countries are committed is critically important - and the only assurance we have that action will be taken to protect the most vulnerable.
The first commitment period of the Kyoto Protocol expires at the end of 2012. So the European Union and the other Kyoto parties (the United States never ratified the agreement, and the Protocol's terms asked little of China, India and other emerging powers) must commit to a second commitment period, in order to ensure that this legal framework is maintained.
At the same time, all countries must acknowledge that extending the lifespan of the Kyoto Protocol will not solve the problem of climate change, and that a new or additional legal framework that covers all countries is needed. The Durban meeting must agree to initiate negotiations towards this end - with a view to concluding a new legal instrument by 2015 at the latest.
All of this is not only possible, but also necessary, because the transition to a low-carbon, climate-resilient economy makes economic, social and environmental sense. The problem is that making it happen requires political will, which, unfortunately, seems in short supply.
Climate change is a matter of justice. The richest countries caused the problem, but it is the world's poorest who are already suffering from its effects. In Durban, the international community must commit to righting that wrong.
Political leaders must think inter-generationally. They need to imagine the world of 2050, with its nine billion people, and take the right decisions now to ensure that our children and grandchildren inherit a liveable world.
Mary Robinson, a former President of Ireland, is President of the Mary Robinson Foundation for Climate Justice. Archbishop Desmond Tutu, Archbishop Emeritus of Cape Town, is a Nobel Peace Laureate.
The views expressed in this article are the authors' own and do not necessarily reflect Al Jazeera's editorial policy.
A version of this article was first published on Project Syndicate.