Many ecosystems are on the brink of irreversible change. We know this even though we may not know exactly when it will happen. We also know that when they change there will be many adverse effects for human wellbeing and health. Healthy ecosystems, healthy people is more than an aphorism: it is a reality with a nasty bite – a bite that is likely to undermine our personal health and community wellbeing unless we change the way in which we manage our ecosystems.

Ecosystems and irreversible change
There is ample evidence that many of our ecosystems are in decline from the effects of expanding and intensifying agriculture. This evidence has been debated often yet we have struggled to adequately react. We know about the adverse impacts of land clearing and salinity, fertilisers and eutrophication, water regulation and invasive species, yet these problems abound. At the same time we face global climate change and have we yet assessed the ecological consequences of globalisation?
 
Catastrophic and possibly irreversible ecosystem changes are looming and they are not irregular. Examples include clear lakes turning cloudy with phytoplankton blooms, seaweeds taking over coral reefs, invasive shrubs taking over grasslands, dead zones developing in coastal waters, saline or polluted soils and water rendering plant growth nigh impossible. Many of these changes are associated with agriculture.

These changes can cause an abrupt switch in the ecological condition of an ecosystem  – a threshold is reached and the system switches to another state. The new system is likely to behave differently and offer fewer ecosystem services that people rely on for their livelihoods, wellbeing and health. Our agricultural systems are not immune. They may have been highly modified to produce food or fibre, but they are still influenced by the same ecological processes that operate elsewhere.

Human wellbeing and health
We place a high value on protecting human health individually and communally. Health is a key component of human wellbeing along with the basic needs for a good life, food, shelter, freedom, security and good social relations. Combined, these provide the conditions for social fulfilment, and reinforce each other, positively or negatively. Human health is interlinked with and influenced by the others. Globally there is increasing acceptance that ecosystem changes may have an effect, at times catastrophic, on human wellbeing and health. This is more and more likely as land-uses that result in the loss of biodiversity lead to step-wise changes in ecosystems, including faster, abrupt and irreversible changes.

Nonlinearities or step-wise changes are also anticipated in social-economic-political systems: for example, widespread food insecurity resulting from climate change and institutional failure worsening inequality or leading to widespread conflict. At the same time a great many less dramatic losses in ecosystem services will also influence human health adversely.

Options and opportunities
One of the biggest limitations in addressing changes in ecosystems is the blindness that has clouded our view of ecosystems and human health. For too long we have seen wellbeing and health as separate from the condition of ecosystems. This may be changing – we are starting to realise that there are endpoints and we may be reaching these, or have even gone past them and may not be able to come back.

Across Australia and world-wide policy-makers are realising that our ecosystems are not only being degraded, but in some cases are perhaps irreparable in human timeframes. The anoxic zones in the Gulf of Mexico and the Black and Baltic seas are possible examples of this. On the other hand The Everglades in the USA have been degraded and are now being restored - at a cost of billions of dollars. The Aral Sea is a dramatic example of social and ecosystem degradation, and there are many more examples.

In Australia we are becoming aware of the consequences of changes in our farming lands and rivers. We have very recently read about the catastrophe facing Lake Albert at the mouth of the Murray. Should we be outward and ask if this is the forerunner of our own Aral Sea? Is this an outrageous analogy? Can we be sure that this will not occur? We have been blinded before. Remember, the mantra that called for the clearing of a million acres of land a year.

To avoid further adverse and irreversible change in our landscapes we need to rethink our management and institutions. We could start by accepting that ecological change is not separable from social change. Do current institutions effectively integrate human wellbeing and ecosystem health? Do we need to reform agriculture, including irrigation? Environment is integral to agriculture. People are integral to environment. Health is integral to economy. Economy is not separable from environment.

Getting sufficient support for social wellbeing and ecological health will require institutional structures that place social and ecological resilience at the centre of economic decision making. This may entail drastic reform. Do we need combined social and environment agencies, or do we need social and ecological resilience embedded within all agencies – within health, water, agriculture and trade?

Max Finlayson is Professor for Ecology and Biodiversity and Director, Institute for Land, Water and Society Charles Sturt University.