Founder director of Forum for the Future
There has always been a problem about the way in which big environmental issues are handled by the media.
The majority of the world's food comes from just 20 crops
Causes once "in fashion" suddenly become invisible; other causes suddenly become all the rage. Today, it's all climate change; if it isn't climate change - from a media point-of-view - just don't bother.
Two weeks ago, for instance, the United Nations Environment Programme (Unep) published its Global Environmental Outlook - a quite devastating audit of the state of the Earth, its habitats, species and resources.
A quarter of the world's flowering plants, for instance, are now threatened with extinction over the next 50 years. There was some reasonable coverage on the day itself (especially in the Independent), but then silence. Environment going to hell in a handcart - heard it all before; so what? Or words to that effect.
Save our seeds
The number of people out there today seriously worried about the health of all the plants and seeds on which modern agriculture depends must be very limited, and the number of people actively campaigning to protect them vanishingly few.
Making these two Radio 4 programmes called Save Our Seeds forcefully reminded me just how crazy that is. Of the Earth's 250,000 plant species, only 200 are cultivated for food on any serious scale.
Even more extraordinary, the vast majority of the world's food comes from just 20 crops, in just eight plant families. Most of these monocultures are dangerously vulnerable to diseases (both old and new), pest infestations, and a rapidly changing climate.
Yet the "genetic pool" on which plant breeders might need to draw to build resistance and adaptability is being constantly eroded as older, non-commercial varieties disappear.
Drawing of the "doomsday" vault to be opened in 2008
There are two ways of protecting the diversity of plants and seeds. The first is through seed banks. I visited the hugely impressive Millennium Seed Bank, set up by Kew Gardens, which is well on its way to collecting, sorting and storing the seeds of up to 10% of the world's flora.
This is just one of 1,400 seed banks across the world, some of them surviving in almost impossibly tough conditions, others well-funded with strong government support.
We interviewed some of the real heroes in the world of seed banks, including the redoubtable Cary Fowler, director of the Global Crop Diversity Trust, who is spearheading an astonishing project to build a state-of-the-art storage facility for the world at Svalbard, way up in the north of Norway.
But seed banks can only do so much in this massive salvage operation. The seeds they store need to regularly germinate, otherwise they too die. The best way of maintaining an active and vibrant seed bank is to ensure that farmers (and gardeners) are planting out those "land races" and rare varieties of plants which are now so endangered.
More often than not, that sets small-scale, subsistence farmers (on whom this kind of "active conservation" depends) in conflict with the juggernaut of industrialised, intensive agriculture.
This battle is far from over, with new efforts now under way to convert much of Africa's land into vast monocultures to produce either food or biofuels for export. And because it's just "seeds" we're talking about here, or nondescript plants for agriculture, the world just stands aside as if this continuing "war on nature" was of little importance.
One suspects that there are some harsh lessons soon to be learned.
Jonathon Porritt is founder director of Forum for the Future and Chairman of the UK Sustainable Development Commission
Listen to Save our Seeds on Radio 4 on Wednesday 7 November and Wednesday 14 November at 2100 GMT