Many have simply lost faith in global climate negotiations summits such as the COP 20 which started in Lima, Peru this week. But while the process has not delivered the climate action we need, I would argue that this year key things have changed and that we must continue to demand from our politicians that they listen and act and, by that, safeguard the future of next and current generations on this planet.
As nations start this latest global round of climate change negotiations, it is easy to be cynical. Because in the 20 plus years that our governments have been meeting for global climate meetings, emissions have risen more than ever before. This year is already predicted to be the warmest since records began.
And yet, this is a moment of opportunity. Because things are changing, really changing. In the climate movement, in the economy and in the politics of climate change. Today, the climate movement all over the world is reenergised. The largest ever climate march in New York this September was a powerful symbol for the global rise of a movement that is stopping pipelines and coal plants as well as forcing renewable energy solutions all over the world.
In economics, too, we live in a different world: Cost-effective, sensible renewable energy solutions have made quantum leaps. Renewables are the most economical solution for new power capacity in an ever-increasing number of countries. One hundred percent of new power capacity added in the United States in August was renewable and countries such as Denmark and Germany are producing new "clean electricity" records almost every month. China is installing as much solar this year as the US has ever done.
The recent bilateral agreement between China and the United States to cut pollution and drive cleaner energy sources is, in addition, a sign of changing politics. Many said that such an agreement was impossible, that it would not happen in our lifetimes. And yet it did. Only a fool would argue that the action proposed by these two biggest polluters and biggest economies is enough.
It is not enough, experts have already told us, to protect our planet from a potential three or four degree Celsius rise in global temperatures - with all the disastrous consequences that would have for us, our children, and our ecosystems.
But the fact that the world's biggest emitters have come together moves us from a "you go first" mentality, that had paralysed global climate negotiations for years, to an "I will act if you will act" frame. At Lima, others must now follow and our pressure must speed up the action.
Because we need an agreement to tackle the climate crisis, which meets the needs of the many not the few. Because it is ordinary people living in flood and drought prone areas, dependent for their livelihoods on fishing, farming and forests, or living in cities engulfed by pollution or in housing that cannot protect them from storms or heat waves, who are bearing the brunt of our experiment with the world's climate.
The United Nations - where every country has a voice, not matter how small, relatively poor or vulnerable - are still the only place where we can hope to secure action that takes full account of these peoples' rights.
At Lima, we need governments to make sure that the direction is right. They need to agree a goal of ending carbon pollution and deliver renewable energy for all people on this planet by 2050. And in Lima, governments must agree to renew and review their targets every five years, starting in 2025.
Not just to cut pollution, but to help the vulnerable adapt to climate change, and to support poorer countries to provide sustainable energy access for their populations.
Every government should already be preparing their "intended nationally determined contribution" - their offer towards the Paris deal. Before March 2015 we must see concrete, ambitious plans from each and every one of the world's polluting nations - to phase out coal and nuclear power, to install solar and wind energy, to increase energy efficiency, to build cleaner and more livable cities, and to protect forests.
In Lima, governments must agree to review whether these plans are enough to prevent climate chaos and whether the effort is shared fairly between richer and poorer nations before they meet again in Paris in December 2015.
In Lima, we expect scientists, business people and investors, city mayors, faith leaders and civil society organisations from all over the world to be calling for more ambitious climate action. The climate movement gets broader and more effective day. It is an unstoppable force now - and in Lima and Paris, we will make our voices heard.