Ecosystems are the foundation for human life. They perform a range of functions, generally referred to as environmental services, without which human societies and economies could not operate at their current level. We depend on the services they provide for air, water, food, shelter and energy. Ecosystems can tolerate a measure of impact from human use and recover relatively quickly with minimal negative effects – an attribute generally known as resilience – but beyond a certain threshold, or tipping point, sudden and radical disruption occurs. Under such conditions, soil quality, freshwater supplies and biodiversity diminish drastically, while agricultural capacity plummets and daily human living conditions deteriorate significantly.
Local ecological collapse may have caused the end of a civilization on Easter Island. More recently, ecological collapse in and around the Aral Sea has had dramatic social and economic consequences for the region, although timely intervention has led to some marked recovery. In today’s highly connected world, local disruptions may sometimes also lead to unintended ecological effects on other far flung areas. This might escalate into the rapid collapse of most ecosystems across the Earth, with no time for effective recovery, drastically compromising the planet’s capacity to sustainably support a large and growing human population.
Since the mid 1950s, many elements that ensure the habitability of the planet are degrading at an accelerating pace.
Ecosystems are complex entities, which consist of a community of living organisms in their non-living environment, linked together through flows of energy and nutrients. The behaviour of an ecosystem is relatively stable over time, but when the balance between some of its elements is altered beyond a certain threshold, it can experience a non-linear, possibly catastrophic transformation.
Human-induced factors that affect ecosystem vitality may be classified in the following manner:
Scholars describe the current historical moment as the start of a new geological era, called the Anthropocene, where humans as the predominant agent of change at the planetary level change the nature of nature itself. Since the mid 1950s, many elements that ensure the habitability of the planet, whether greenhouse gas concentration, forested areas or the health of marine ecosystems, have been degrading at an accelerating pace. In 2009, an international group of experts identified nine interconnected planetary boundaries that underpin the stability of the global ecosystem, allowing human civilization to thrive. Research indicates that we have exceeded safe limits for four of those, and are now operating in a high-risk zone for biosphere integrity and biogeochemical flows. Unless we rapidly change trends and adopt a new sustainable paradigm, we are very likely to exceed all nine boundaries, and leave the safe operating ecological space where humanity has thrived.
Unless we rapidly change trends we are very likely to leave the safe operating ecological space where humanity has thrived.
The changes in Lake Chad have been called an ecological disaster that have not only destroyed livelihoods but also led to the loss of invaluable biodiversity. Lake Chad traverses Chad, Nigeria, Niger and Cameroon. The lake was considered as the sixth largest lake in the world in 1960s but over the last 60 years, the lake’s size has decreased by 90 per cent as a result of over use of the water, extended drought and the impacts of climate change. The surface area of the lake has plummeted from 26,000 square kilometers in 1963 to less than 1,500 square kilometers today, affecting the livelihoods of over 40 million people that depend on it. The fluctuation of the lake is attributed to the complex interaction of several factors, including the shallowness of the lake, changing human uses of the lake water such as increased water use for irrigation and the effects of climate change. A scientific assessment on the situation of the lake ranked freshwater shortage as severe and as a primary concern affecting other changes, including habitat modification and declining fish production. The diminishing water resources and the decline in the lake’s ecosystem leads to severe health and economic impacts for the populations around Lake Chad, and has affected fishing communities and pastoralists, and also generated resource-based conflicts.
Associate Professor of Global Governance and Director, Center for Governance and Sustainability, University of Massachusetts Boston; Global Challenges Foundation Ambassador
Research Fellow, Natural Resources and Ecosystems, Stockholm Environment Institute