Traditional techniques also promise a degree of insulation from the ever more costly business of using fossil-fuel dependent, artificial inputs. Sustainable, agro-ecological approaches are the ones that could produce the sorts of diverse foods that Africa needs. It is these techniques that will prove resilient in the face of the challenging economic and environmental problems we all now face.

Chancellor, Ministers, Distinguished guests,

It is a great pleasure to be with you today, in this extraordinarily beautiful country which, in so many ways over the last two decades, has provided a beacon of hope for many people across Africa and beyond.

With the Durban Climate Conference, COP17, only a few weeks away, you have been kind – or rash! - enough to ask me to share with you some of my thoughts on the challenges that lie before us in tackling climate change and international sustainability. My wife and I are seeing how a diverse range of rural and urban communities are facing up to these challenges during our current visits to South Africa and then to Tanzania next week. Cape Town, though, could hardly be a more appropriate location to explore these themes. It is a city surrounded by one of the most biologically diverse places on Earth; it lies adjacent to highly productive ocean fisheries; and it sits at the Southern tip of a continent which is not only already having to cope with the impact of climate change, it is also wrestling with the consequences of an intensified demand for land. In differing degrees, these difficult issues are replicated right across the world. As we are seeing, there is a growing mismatch between what we demand of the Earth's resources and the ability of Nature's systems to respond. I need hardly say that we will all be defined by how we respond.

Ladies and gentlemen, in Southern Africa you are only too aware of the tensions that come from competing demands on the land. Land is the most fragile and precious of all our commodities and, as I have tried to indicate over the years, there is mounting evidence that, worldwide, we cannot carry on as we have been without suffering some very painful consequences. What with the ever-growing need for more urban development and the pressure to produce more food, it is fast becoming difficult to maintain those essential services, such as the supply of clean water and, ultimately, to protect those areas that are rich in the diversity of life and which, whether we like it or not, are actually vital if Nature is to continue sustaining herself and, therefore, us.

Add into the mix the impact of climate change and suddenly all the risks to stability are multiplied. Just consider, for instance, the way fluctuating food supplies and the spiralling demand for substances like biofuels lead to extraordinary volatility in food prices. Consider, too, the many problems that come from increased migration. This unholy combination can pose significant threats to national security, though the issues are rarely if ever seen through that prism.

I, for one, have been incredibly heartened by Cape Town University’s decision to appoint a pro-Vice Chancellor for Climate Change – an idea which I can only hope will catch on elsewhere! One of the issues which will no doubt be taxing the pro-Vice Chancellor and the wider Faculty will be ways in which to mitigate many of these inter-related problems.

Surely one starting point would be to convene representatives from various key sectors to explore the development of an economic system which is more able to withstand the sorts of shocks that will, I am afraid, only become more frequent and more severe in the years ahead. To do so, we have to create a framework that is sensitive to the relationship which exists between food security, water security, energy security – and, indeed, national security – and to the issues of how human wellbeing can be achieved without further loss to the planet’s ecological integrity. This is absolutely essential if we are to lift out of poverty the three billion people around the world who live on less than two dollars a day.

Many of these people live in rural areas or have recently been displaced to urban centres; it is a sad irony that it is often farming families who themselves increasingly go hungry. We have to resolve this growing problem. It requires investment, both public and private, in agriculture and in rural economies. And, as well as financial investment, the situation needs solid public policies that support farmers as well as farming.

The scale of what is needed is, I am afraid, astonishing. The International Fund for Agricultural Development, for instance, estimates that there is a global short-fall in investment in the developing world's agriculture of at least fourteen billion U.S. dollars a year.

I have spent many years considering these problems and, indeed, their solutions and I am convinced that much could be done quickly, easily and cheaply if we set our minds to it. If nothing else, surely it cannot be beyond the wit of Man to work out how to reduce the fifty per cent of food that is currently wasted post-harvest before it reaches market, or how to allow farmers access to easily available seeds that could double or triple yields, all without the need for new varieties of seeds.

Alongside governments, if I may say so, the private sector also has a vital role to play, including those in the retail sector. They are very important agents for change. I have been struck, for example, by the wonderful work done by Pick and Pay here in South Africa to link small farmers to retailers and consumers. I am sure that much more can be done in a similar way to build that relationship between consumers and farmers. In fact, I wonder if global organizations like the Consumer Goods Forum could help here by championing new ways to support more resilient farming through their supply chains?

I need hardly say that change must also come in our approach to how we utilize the global marine environment. As you will know better than me, many fisheries are over-exploited and some are close to collapse. Yet 560 million people depend on fisheries for their livelihoods. South Africa has made important progress in recent years, especially in relation to the management of hake. Earlier today I was able to see for myself how this fishery has become more sustainably managed, and is certified by the Marine Stewardship Council. There has been enormous progress in reducing by-catch, including the inadvertent capture and killing of remarkable seabirds such as the albatross. The work done here by remarkable organizations like Bird Life International through their “S.O.S. - Save our Seabirds” initiative, is, I think, a wonderful example of what can be achieved with the right kind of leadership.

I am happy to say that my International Sustainability Unit, or I.S.U., has been drawing inspiration from this work and that of other leading fisheries to help facilitate a consensus on possible ways forward – in the same way, incidentally, as it has been trying to find innovative ways of avoiding the disastrous destruction of the world's precious rainforests – all to promote more resilient and sustainable fisheries. And to my great relief, a consensus is beginning to emerge. The focus is on the better management of fisheries so that they produce not only more food, but also much greater economic gain. One widely quoted estimate from the World Bank and their “Sunken Billions” research suggests that if the world's fisheries were better managed their value could increase by some fifty billion dollars a year. This is why, in consultation with the global fishing industry, with N.G.O.’s and international agencies, we have been looking into how this can be achieved and I have been greatly encouraged to find that there are three points where broad agreement appears to exist.

The first is the recognition that we have to take an ecosystem-based approach towards the management of fisheries, rather than exploiting them without proper consideration for the natural systems that sustain them. This requires better research and methods of data collection. We also need to think about planning; about different kinds of property rights and using alternative forms of fishing gear. Again, the South African hake fishery is emerging as a leader as it attempts to manage the whole system, rather than setting a particular target population of fish.

The second part of the jigsaw is to ensure that proper governance is in place. The process needs to be properly monitored and enforced and illegal fishing controlled. Without this, there is often little chance of establishing the sustainable management of fish stocks. However, cheap and widely available technology is available that can identify individual vessels.

The third point of agreement is around the need to alter the economics of fisheries, so that people in the industry can make a good living while, at the same time, the resource is properly managed. The range of options includes the use of certification to gain better market access for more sustainable fish, as your own hake fishery is now using. At the same time, I cannot help but wonder if it might also be possible to reorientate the focus of some public subsidies so that they employ measures to encourage private investment in more sustainable fisheries?

It seems to me, ladies and gentlemen, that we have a range of approaches that could make a very big difference indeed and create a more resilient and sustainable food system, both on land and at sea. I believe that we can do this while, at the same time, conserving the natural capital – the entire, complex, often delicately balanced ecosystems that are the ultimate source of all our wealth. And that includes the incredible biological diversity that makes areas of the world like South Africa so beautiful and so uniquely precious for our future survival.

The issues are complex and the connections between them are many and varied, but I believe that through dialogue we can find ways that will be of benefit to the many different interests, organizations and countries that must be part of the solution. To that end, I hosted a meeting a few days ago in London which brought together representatives of the REDD+, Climate Smart Agriculture and agriculture sustainable round table communities – a meeting , I am delighted to say, that was attended by your Minister of Agriculture, Mrs. Joemat Pettersson. I was heartened to see – and I think some of them were slightly surprised to discover! – that not only do their goals overlap, but so too their conditions for success. I am talking here particularly about co-ordination, planning at national and sub-national levels and about the ability to reach out to people on the ground. I hope that this meeting may, if nothing else, generate a shared understanding of what might be achieved if everyone works together rather than in isolation.

In fact it is an example, if I may say so, of what could happen if there was a willingness on the part of different constituencies to seek the solutions that lie behind the apparent wall of paralyzing dilemmas and conflicts. I have found time and again that dialogues like this can help to reveal some of the many opportunities that exist. For instance – and this is of enormous and topical importance – I wonder if this might also apply to the increasingly complex issue of foreign investment into agricultural land in emerging economies? This investment, given the need for the injection of foreign capital into agricultural productivity, should in many ways be welcome. It is absolutely essential, but it surely has to be done with particularly careful regard to how it affects both the people on the ground and the natural systems and environment? It is perhaps of note that the World Bank reported that, in 2009 alone, deals were announced that concerned some fifty-six million hectares of large-scale farmland, and that the most attractive countries for such investment were in Sub-Saharan Africa.

It seems to me absolutely essential, though, that such an investment is mindful of its impact on communities and natural systems. Indeed, I can only echo the words of Kofi Annan who recently said how very disturbing it was to read a report which found that agricultural land “that adds up to the size of France was bought in Africa in 2009 by hedge funds and other speculators.” And he added, “It is neither just, nor sustainable, for farmland to be taken away from communities in this way, nor for food to be exported when there is hunger on the doorstep.” Investments of this kind may generate significant profits for those involved, but experience cautions that this kind of investment is full of risks. It is profoundly distressing to learn of numerous rural communities being evicted from their ancestral lands in the headwaters and upper floodplains of great rivers like the Nile and Niger to make way for export-oriented estates whose giant irrigation canals may permanently destroy swamps that are crucial for both the region's biodiversity and traditional ways of life, including those downstream. Or the threat to Lake Turkana that supports the peoples and desert ecosystems of much of Northern Kenya and neighboring Southwest Ethiopia, including two World Heritage Sites, which would be devastated if its main source of water, the Omo River, were to be dammed and diverted for sugar and biofuels. Surely Africa needs to heed the lessons from tragedies elsewhere, like the desiccation of the Aral Sea that resulted from similar developments to produce much more cotton, but created far reaching consequences of unimaginable proportions.

And the Nobel Laureate, Wangari Maathai - whose tragic loss I can only mourn with all my heart - consistently pointed out how the devastating impact of such acquisitions not only threatens precious environments, but also the lives and wellbeing of thousands of ordinary people. With remarkable courage she showed, above all, how much can be achieved with local knowledge, skills and the energy of the people on the ground. She was always clear that this will not be achieved if the system depends entirely upon importing large scale or top-down technocratic solutions.

In company with many, I wonder if greater returns could come for Africa if attention were paid to backing the continent’s millions of smallholders? And yet, as I speak, many are being driven off their land and swelling the ranks of the urban dispossessed. Is this what we really want as the only answer to so-called food security? I do not see small farmers as backward relics of the past. In fact, I see them as an utterly crucial cornerstone of the future, just as they are becoming in other parts of the world. This is because smallholders typically understand the complexities of their local environments. They also have the capacity to innovate and test new approaches – a skill which is often under-appreciated. And, by virtue of the traditions they adhere to, they are often the people who are not swayed by the pressures of short termism that can dog the corporate world. Instead, they tend to think about the long-term, with a focus on the health of their soils and the coherence of their communities. They can make a very considerable difference, if they can be protected from the ravages of extreme poverty and insecure land tenure and be allowed to farm using techniques which are appropriate to their complex and variable environments.

Traditional techniques also promise a degree of insulation from the ever more costly business of using fossil-fuel dependent, artificial inputs. Sustainable, agro-ecological approaches are the ones that could produce the sorts of diverse foods that Africa needs. It is these techniques that will prove resilient in the face of the challenging economic and environmental problems we all now face. And in case you are wondering, it is not just me saying this... An impeccably well-researched International Assessment of Agricultural Knowledge, Science and Technology for Development, conducted by the U.N. in 2008 drew on evidence from a wide range of international scientists and concluded that small-scale, family-based farming systems, adopting agro-ecological approaches, were among the most productive systems in developing countries. So, with the right policies, with strong but wise investment and other support, including access to markets that value the quality of their products, these people are key. Their conclusion, in short, was that Africa depends upon the grass roots entrepreneurship of its own citizens.

Tragically, many of the land acquisitions do not encourage this kind of development with its emphasis on the viability of smallholder economics and, it appears, they may lead to serious social and environmental problems. One of the issues apparently is that, until it is too late, it is very difficult for many of the stakeholders to have a clear understanding of the size, type and implications of these investments. There is, then, an urgent need for greater transparency in land deals so that communities, and Africa as a whole, can evaluate which investments are in their best interests.

What would also help is if investors could be encouraged to take a more considered approach, and to incorporate not only an assessment of the financial returns, but also what can be achieved socially and environmentally. From what I know of this intricate subject, I would have thought that investors would find this a sound strategy. Indeed, if investors better understood these wider and deeper questions and managed the way their investments were employed properly, they might well be less exposed to financial risk…

With this in mind, the World Bank and the U.N.’s Food and Agriculture Organization have both published principles intended to set standards for good practice. I am pleased to say that some leading investors are now prioritizing projects that have a positive environmental and social outcome. There is certainly a glimmer of hope from the fact that a small group of Pension Funds has adopted a set of “Principles for Responsible Investment in Farmland.” It is also worth considering the view of the U.N.'s Special Rapporteur on the Right to Food, Mr. Olivier De Schutter, who has pointed out that these positive measures will be most effective when first grounded in local land rights and good governance.

However, if we are to improve agricultural productivity – but in a way which supports smallholder farming – then those very smallholders need to have access to the appropriate education, training and skills if they are to be successful and sustainable. Around the world, as much in Europe as in Africa, these so-called “agricultural extension services” have more or less disappeared. Education for the farming community, as often as not, now comes veiled by the vested interests of a fertilizer or pesticide salesman… Given the challenges we are facing, ladies and gentlemen, investment into these “extension services” is of the greatest importance. Indeed, without it, it seems hard to imagine how a genuinely sustainable rural economy can be built.

Looking across all these themes it seems to me that an important opportunity exists to bring together the narratives of climate change, sustainable development and economic stability (surely the very bedrocks of national security…). These are currently encapsulated – although separately and distinctly – in the forthcoming COP17 in Durban, the Rio+ 20 conference and G20 meetings. Might it not, therefore, be worth considering a mechanism by which these themes could be brought together to achieve a much-required strategic and tactical response to the challenges arising from the depletion of our natural capital?

On a practical level, one starting point might be to ensure that we use the data collated on energy, water, agriculture, biodiversity and climate change to compose a full picture of what is actually going on, and then to use this picture to calculate the real cost of our current use of natural capital. Surely an evaluation of that cost on an on-going basis is the bare minimum we need if we are to develop effective policies that address food security, poverty and climate change, and so build properly resilient economic systems – green economies, if you will – that have the capacity to adapt to what will, from now on, be very rapidly changing circumstances?

Let us not forget that such reviews – arriving at an internationally agreed cost of action versus inaction – have helped crystallize minds and thinking in the past… As former President Nelson Mandela so wisely once said, “it always seems impossible, until it is done.” If it is not done, all I can say is that our children and grandchildren will face a disastrously compromised future…