COPENHAGEN - I have been working on climate change for many years, first as a researcher in my native Bangladesh and later as head of the climate change group at the International Institute for Environment and Development, and as a member of the Intergovernmental Panel on Climate Change.I have seen first-hand the threats climate change poses in places such as the drylands of Africa, the mountains of the Himalayas and the vast low-lying deltas of Asia. I have observed years of inaction at UN climate change summits that have failed to deliver the response needed because negotiators have chosen to protect narrow national and economic interests instead of rising to the challenge of protecting future generations.
I have jousted verbally with climate-change deniers who have strong links to polluting industries and who have never set foot in the vulnerable villages and urban communities where climate change is already having impacts. If they did they would realise the damage their ideology does to the people who have contributed least to this global threat.
And now, in Copenhagen in December 2009, I believe we have reached a tipping point. I truly believe that Copenhagen will be remembered in years to come, not for what happens on 18 December when world leaders meet here, but for what just happened on 12 December.
This marked the day that people from all walks of life all over the world seized the initiative from our so-called leaders. Regardless of the words these presidents and prime ministers decide in a "protocol" or "agreement" next week, it is the people of the world who have put the writing on the wall!
The leaders who choose to read those words will take us forward. Those who ignore them will be swept away by the tide of history.
Yesterday marked the point when a large part of the world rose up as one to tackle a truly global challenge. Although there may be temporary setbacks (like a less-than-ambitious deal next week) the tide has already turned. It cannot be turned back.
Regardless of how much we achieve next week - and I remain optimistic in spite of the political manoeuvrings last week - we are set on a new and inexorable path. The leaders who understand that may come from the most unexpected of quarters. Keep your eye, for instance, on President Mohamed Nasheed of tiny Maldives.
In a few months I shall be moving back to Bangladesh to fight real climate change, as opposed to fighting against bad (or inadequate) climate change policies. My ambition over the coming years is to help the people of one of the poorest and most vulnerable - and yet resilient and innovative - countries transform itself from being the world's iconic "vulnerable" country to being recognised as perhaps its most "adaptive" country.
I am going home to set up a new International Centre for Climate Change and Development (ICCCAD) where we aim to ramp up the capacity of governments, civil society organisations, researchers, academics, journalists and many others from developing countries to respond to the challenges that climate change poses.
The new centre will provide training and share knowledge on how to survive (and indeed even thrive) in a globally warmed world. It will focus primarily on adaptation to climate change in the least developed nations but will not stop there.
Indeed we are planning to provide capacity building for industrialised countries on how to face adverse climatic impacts. Ironically, unlike most of the world's poorest countries, the rich world that has caused this problem has not done detailed planning on how to adapt.
I am returning to the front line of climate change where the real fight is already underway. I go there knowing that millions of people around the world share my hopes and my optimism that humanity can unite to tackle the challenge that now defines our life on Earth.