Limited by nature

There were two billion people alive when I was born; there are six billion now; and there may be another three billion before my son dies. That will require 80 per cent more food, water and other resources: way beyond our earth’s already overstretched capacity. No species can increase its numbers like that indefinitely without serious risk of systemic collapse. Fundamentally, there can be no prospect of a sustainable society unless we can stabilise our numbers and live within the earth’s means.

My greatest worry is that complex, interlinked ecosystems - forests, reefs, lakes, rivers, oceans and their food webs - could suddenly collapse, after seemingly few small extra pressures. There comes a tipping point after which change is swift, dramatic and irreversible. This is what scientists call criticality, and it is nearly impossible to predict.

The abrupt collapse of the Saharan rainforests to desert is an example of ancient regime shift. The collapse of Caribbean coral reefs and the Nova Scotian cod fisheries are recent cases that no one predicted.

A simple equation determines the earth’s fate and ours: the number of people multiplied by how much they consume and dump.

The optimists have unshakeable faith in economic miracles, claiming, “We’ll fix the problems when we can afford it but only growth will produce the extra cash and technological innovation to do so”. It is true that for many, but not all, quality of life has improved dramatically. There is enough food. We live longer and better and can replace bits of ourselves that wear out, thanks to remarkable scientific achievements. We can be thankful for many positive changes.

But this economic wealth is fuelled at huge ecological cost by more consumption, more than we really need or want. The food, water, fibres and fuels to feed, clothe, shelter, coddle and move us around comes from land and energy we take from the other 500,000 or so species vital to this earth. We have already seized more than half their share.

To sustain our food lifeline we now fix more nitrogen synthetically (in fertilisers) than do all terrestrial ecosystems naturally. Whole seas, lakes and rivers are being starved of oxygen and dying as a result. Water use, largely for agriculture, is surging and reducing rivers to bare trickles. We are acidifying our oceans more than at any time in the past 300 million years. More species are becoming extinct than at any other time in the last 60 million years. The fossil record tells us that recovery from these mass exterminations takes 20 million years or more. There is no quick fix. Some think it too late already, that all life on earth is doomed. I don’t.

Assuming we get our population policy right can we harness smart technologies now to spare and heal the land? Can we sustain reasonable quality in our lives with less land, less water, less waste and fewer new resources? Remote technologies (Landsat, Modis satellites) show the state of our land in broad terms, but often too late, when the damage is already done and it is too slow and costly to reverse.

We need in situ data, in real time and at the right scale, to see the trends and guide day-to-day decisions. For each farmer, each grazier and each paddock - how much and what to plant, where and when; how many stock and for how long. We need to know in which paddock, when to water and how much, in order to maintain land and stock in good condition, yet remain profitable, productive, efficient and sustainable. Our rivers and reefs would become free of silt and sludge.

Wireless sensor network (WSN) technology has the required capacity to revolutionise agriculture and grazing - by doing more with less, and environmental monitoring. It involves thumb-size computers (“motes”, “flecks” or nodes) combining microprocessors, memory, radio transceivers, onboard power supplies and a host of sensors that can measure moisture, heat, pressure, temperature, pH, turbidity, chemicals, sounds, light, images, electro-magnetic fields, vibrations and much more.

These will eventually be inexpensive enough to deploy in the thousands on farms, forests, reefs, lakes and streams: collecting data at spatial and temporal scales previously inconceivable and unaffordable.

Each node is linked wirelessly to others in grids or clusters to collect and analyse data from sensors before transmission potentially around the world. This means we can immediately detect or even pre-empt the first outbreak of pests, infections or disease in crops and pastures, applying just the right amount of chemicals in just the right place, with savings in costs and pollution, and increased production. One could automate delivery of fertilisers precisely to meet the spatially variable needs of soils across each farm or paddock, at a fraction of today’s usage and costs.

To restore even 1 per cent of habitat needed for viability and ongoing evolution of Queensland’s unique flora and fauna would cost between $25 and $100 billion by traditional means. This is clearly prohibitive. The hundreds of millions already spent, if on wrong species mixes, may impede long-term recovery. If one thinks in ecological timeframes, WSN could help us learn from and assist nature to recover, affordably, on a scale that matters.

I can think of no other single technology with such powerful and diverse applications. This technology can achieve a more secure and sustainable “natural” environment for biodiversity and can reduce ecological footprints while improving the profitability, productivity, efficiency and sustainability of those industries that succour us, but threaten biodiversity the most.

But in the end, WSN is just a technology: respect for the earth and a passion to heal it is fundamental.