Ladies and gentlemen, I am most flattered to be invited to open proceedings at this Avoided Deforestation Partners meeting and I am so sorry that I cannot be with you today. Needless to say, I have followed very closely the debates and decisions of the various Earth Summits since the first one in Rio twenty years ago, some fourteen months prior to which I recall facilitating a preparatory international gathering on board the Royal Yacht Britannia in the Amazon Delta.

It was attended by President Collor, the then President of Brazil, and I remember that the link between forest clearance and agriculture was prominent throughout. Everyone recognised the need to conserve and enhance the world's forest resources, not only as the reserves of great biological diversity, but as sinks for carbon emissions. It was seen as a key goal and would only be possible with a mix of national policies underpinned by international co-operation.

For me, and I dare say for many others, there is a terrible sense of "déjà vu" when I recall those expressions of urgency twenty years ago. To say that your event could not be more timely is most certainly an understatement. Although a certain amount has been achieved, we still have to implement those fundamental changes needed to meet the multiple challenges we face. And we do not have much time.

When I was last in Rio just over three years ago, I emphasised in a speech the fact that many in the scientific community were warning that we had less than a hundred months to act in order to avoid catastrophic Climate Change. That was forty months ago and Nature's capital reserves, chief among them the rainforests, are still being eroded at a rate nature struggles to cope with. We simply cannot wait for international frameworks to be put in place. If the pace of the negotiations and the speed with which agreements are implemented is too slow to arrest the present rate of depletion, then it seems to me we have no option but to forge ahead by taking action now, then linking it with the international frameworks when they finally emerge further down the line.

There is, of course, huge pressure on our agricultural systems to produce not just more food, but commodities like cotton and bio-fuels. Unfortunately, it is still economically rational in many cases to meet this demand at the expense of forests. Despite the welcome reduction in deforestation in some parts of the world, such as here in our host country, Brazil, the burning continues - and not only of forests. Every year a billion hectares of grassland goes up in smoke in Africa and South America, releasing vast quantities of greenhouse gases, in order to make way for much-needed agriculture. But what we cannot lose sight of is the need to ensure that changes in production practices that could meet the growing demand for food, textiles and energy, not only deliver benefits in the short-term, but create durable and resilient food systems for centuries to come. They have to be approaches that enhance nature's capacity to sustain such systems and feed a more stabilised global population. Given that the majority of forestry is cleared for agriculture, it is worth bearing in mind that it is no good arresting deforestation by boosting agricultural output in ways that exacerbate the environmental and social problems we are currently trying to wrestle with. In other words, there is absolutely no point in being seduced into developing a second 'Green Revolution' which merely repeats many of the same disastrous mistakes of the last one, but in a more enticing 21st century technological guise.

However, there are reasons to be optimistic. There are solutions to this intricate puzzle, although they are often specific to different locations and agricultural systems. My International Sustainability Unit, or I.S.U., has been studying these complex problems for some time, to understand what is required by farmers and other stakeholders to improve agricultural production without tearing down yet more forests. Following analysis and a series of workshops in South America, Africa and Asia involving, often for the first time, key representatives of the private sector, government, civil society and the international community, the consensus was that, theoretically, it is possible to enable farmers to increase production without it being at the expense of forests.

For example, the analysis suggests that farmers in Central Kalimantan could double palm oil production by 2020 without more deforestation, increasing yields of smallholders by expanding farming onto low carbon land. Soya expansion could take place on degraded pastures in Mato Grosso. In both cases this would need to be combined with those processes that safeguard biodiversity - things like biodiversity corridors, agro-forestry techniques and ways of rehabilitating and reforesting river systems. In the Mato Grosso cattle could be reared among trees and other crops, thereby making cattle ranching productive without intensifying the process using artificial means. If all this were to be adopted, the estimate is that the state's total agricultural output could grow without further clearing and without destroying yet more of the world's vital biodiversity.

I have to say here that a recurring nightmare I have is that unless we learn the lessons of history, the so-called 'second green revolution' will merely involve vast swathes of recently cleared rainforest and grasslands in South America and Africa being turned over to produce intensively fertilised, hybridised protein crops which are then fed to factory-farmed pigs, chickens and dairy cows, all in pursuit of satisfying an insatiable and ultimately unsustainable appetite for meat. Any development of degraded pastures must therefore employ the sorts of effective measures I have just mentioned that preserve and protect the region's biodiversity.

At the moment, I'm afraid, there is too much 'business as usual' in some cases because farmers are unable to invest in alternative modes of production. They may also lack knowledge of the alternatives, or they are not provided with sufficient incentives to adopt best agricultural practices. These obstacles can, and must be overcome. To do so, focussed interventions are needed with transition finance offered to farmers if they are willing to adopt improved practices. And, of critical importance, we also have to find ways of revitalising and, if necessary, rebuilding rural development extension services. This would all be part of an eco-system based approach to agriculture which the U.N. itself, four years ago, declared to be one of the most productive approaches in developing countries. The report it published by the I.A.A.S.T.D was impeccably well-researched and drew on the evidence of more than four hundred scientists. If you'll forgive me for saying so, I would have thought that we ignore such findings at our peril...

Tackling the problems of deforestation and food security in a coordinated way offers substantial win-win opportunities - at a time when, despite the sloth-like pace of negotiations, billions of dollars have been pledged to pay for reduced emissions from deforestation and greater amounts pledged to achieve food security. And let's just be clear what I mean by "food security." It has to be a form of agriculture that does not exceed the carrying capacity of its local ecosystem and the communities it supports. It can only be done by enhancing, rather than diminishing, the natural capital upon which we depend for our long term well being. This is why we have to start thinking about reshaping consumption patterns, so that we align them in a far more far-sighted way with the very real constraints of our planetary boundaries.

So it would surely be advisable if the funds to enable trials to begin in transforming agricultural systems and building sustainable supply chains were used strategically, across sectors and regions, to ensure the systems we build today are not unravelled, yet again, by a lack of systemic thinking and foresight tomorrow.

I am reminded of powerful words once spoken by Sir Winston Churchill on the eve of the cataclysmic events of the Second World War. He argued that we cannot afford to go on in strange paradoxes "being decided only to be undecided; resolved to be irresolute; adamant for drift; solid for fluidity." Hard lessons have surely been learnt from not putting nature at the centre of our economic calculations over the past century. Now, as never before, is the time to re-integrate nature's economy with our own so that, instead of living dangerously off nature's rapidly diminishing capital, we draw a sustainable income from the wise management of that precious capital. Now is the time for focussed, integrated thinking and for collective, decisive action.