A stark warning
With more than a thousand eminent scientists agreeing we are living beyond the capacity of the planet to support us, CIWEM executive director Nick Reeves asks can we learn to live within environmental limits?
It's true, and it's scary - carbon emissions are still increasing and we are not getting to grips with human-induced global warming. Meanwhile we are living way beyond our means, and beyond the ability of the planet to sustain us. That is the message from 1,300 of the world's most respected scientists, who have contributed to the UN Millennium Ecosystem Assessment (MA).
They have agreed almost two-thirds of natural life support systems are being destroyed by human activity and by the way we live now. The stark warning is this - we are in ecological overdraft and if the developing world achieved the same standard of living as countries in the northern hemisphere, we would need the natural resources of at least three, and possibly four, planet earths.
According to the doom-sayers we have got ten years to change our ways before catastrophe kicks in. The wetlands, forests, savannahs, coastal fisheries, estuaries and other habitats that recycle water, air and nutrients for all living things are being irrevocably damaged. The killer fact is this - one species is a threat to around 10M other species, and therefore to itself. By diminishing nature we harm ourselves. Human activity is putting such a strain on the earth that the ability of its ecosystems to sustain future generations of people can no longer be taken for granted.
Our demand for water, food, timber and fuel means that in the last 60 years more land has been claimed for agriculture than in the 18th and 19th centuries combined. Around 24% of the earth's land surface is now cultivated. Meanwhile consumption of water from lakes and rivers has doubled in the last 40 years - we now use 50% of all available freshwater. In the developed world we use 50% more than we need to live healthy lives.
The damage does not stop there - at least a quarter of all fish stocks are over-harvested. Recent research has also shown that since 1980 about 35% of mangroves have been lost, 20% of the world's coral reefs have disappeared and another 20% are badly degraded. Flow from rivers has been reduced dramatically. For parts of the year, the Yellow River in China, the Nile in Africa and the Colorado in North America dry up even before they reach the ocean. An estimated 90% of the seas' large predators have disappeared in recent years - sharks, swordfish and tuna.
An estimated 12% of birds, 25% of mammals and more than 30% of all amphibians are threatened with extinction within the next century - some of them by invaders from other parts of the world as a result of climate change. Global warming will make it increasingly difficult for surviving species to adapt. Most people only seem capable of measuring value in terms of hard cash, so a team of scientists and economists tried to put a value on the 'services' and benefits provided by nature - the availability of water, the free pollination of crops, the air conditioning provided by wild plants, the recycling of nutrients by the oceans. They came up with a figure of around £63trillion, almost twice the global gross national product.
So, given what scientists are now telling us about the state of the planet, it is time to check the accounts. With even a cursory look, I think what we would find is more red ink than black on the balance sheet. We would see we are living on borrowed time. By using up supplies of fresh groundwater faster than they can be recharged, for example, we are depleting assets at the expense of our children. More and more people live in cities, living such advanced café culture technological lifestyles that their contact with nature has become, at best, no more than a hobby. Nature is not something to be enjoyed at the weekend or on holiday, and nature conservation is not just a hobby or past-time. These are dangerous illusions that ignore the vast benefits of nature to the lives of 6B people on the planet. We may have distanced ourselves from nature but we rely completely on the services it provides.
In the south-east of England the government is planning to build hundreds of thousands of new homes where there is a risk of flooding, where there is already water scarcity and where more than 25% of the population lives on 10% of the available land. We are told technofix solutions will make this possible and the new communities sustainable. Against a background of human induced climate change, species loss and unsustainable economic growth around the world, l doubt this is do-able.
I fear we are unwilling to appreciate humans are, in truth, an invasive weed. Archaeology, history and ecology all show us people have always determinedly exploited natural resources - water, timber, soil. Growth has never been based on sustainable resources that are replenished in short-term ecological cycles and we know full well short-term cycles are disrupted by economic growth.
If a politician took decisions as if the main issue of the day was "our ecology, stupid" - rather than Bill Clinton's famous "It's the economy, stupid" - then he or she would be confined to the political wilderness. Sustainability is part of the politician's rhetoric. When is it going to have real meaning?