Ecological collapse

What is at stake?

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 would not operate at their current level. We depend on the services they provide for air, water, food and fiber, shelter and energy. Ecosystems can tolerate a measure of impact from human use and recover after a period of time with minimal negative effects – an attribute generally known as resilience – but beyond a certain threshold, or “tipping point”, sudden and radical disruption occurs, which may lead to “ecosystem collapse”. Under such conditions, soil quality, freshwater supplies and biodiversity diminish drastically, while agricultural capacity plummets and daily human living conditions deteriorate significantly.

Although little studied, new evidence is emerging on “ecosystem collapse” due to among other factors, human pressure, and climate impact. 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. Ecological changes in Lake Chad has not only destroyed livelihoods  with dramatic impact on people and ecosystem of the region; 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 generated resource-based conflicts. 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. And with no time for effective recovery – and amplified by climate change impacts-  drastically compromising the planet’s capacity to sustainably support a large and growing human population.

"...compromising the planet’s capacity to sustainably support a large and growing human population"

How much do we know?

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:

  • changes in the balance of local biodiversity caused by human intervention, in particular as a result of introducing new species or overharvesting of plants and animals
  • alteration of the chemical balance in the environment – soil, water and air – due to pollution
  • modifications in the local temperatures and water cycle because of climate change
  • habitat loss, whether through destruction or ecosystem fragmentation in terrestrial and water/sea systems.

    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. It is argued that humanity has exceeded the safe limits for four of the planetary boundaries, and are now operating in a high-risk zone for biosphere integrity and biogeochemical flows, and are very likely to exceed all the nine boundaries, and move beyond the safe operating ecological space where humanity has thrived.

    New evidence suggests that changing course to stop the pervasive human-driven decline of life on Earth requires transformative change.

    What are key factors affecting risk levels?

    The development and adoption of new technologies or production models that are less resource-intensive and/or less polluting could reduce the risk of biodiversity loss and ecological collapse, as would a shift towards more sustainable lifestyles, more specifically changing consumption patterns, possibly accompanied by behaviour change.

    It is estimated that environmental services, should their contribution to human well-being be calculated, would be worth more than twice as much as the entire global GDP. Integrating the valuation of ecosystems into economic decision making, reviewing our measures of economic success, and employing robust environmental accounting systems across businesses and national economies would contribute to reducing the risk.

    Global governance mechanisms to conserve ecosystems and reduce pollution, in particular more integrated approaches between the global governance of ecosystems and economics and trade, are of particular importance, as many ecosystems do not overlap with national boundaries, and trade is an important driver of ecosystem collapse.

    Ecosystem collapse in Australia and Antarctica

    A recent study assessed evidence of collapse in 19 ecosystem (both terrestrial and marine) that cover approximately 1.5% of the Earths surface extending from northern Australia to coastal Antarctica, looking at environmental changes over the past 30 years. The study applied four criteria to assess collapse (abrupt, smooth, stepped and fluctuating), and found evidence  of local collapse  for all the 19 ecosystems studied, although none has collapsed across the entire distribution. The collapses were as a result of ecosystems experiencing multiple pressures simultaneously, including, pressures from global climate change (such as temperature rise, altered precipitation and ocean acidification, and pressures arising from regional human impacts (such as habitat loss, pollution and water extraction) acting together to erode biodiversity. To deal with this challenge of ecosystem collapse, the authors recommend a three step approach of promoting awareness of ecosystem values, anticipation of pressures, and taking action to manage the impacts through recovery, restoration, renovation and adapting to the changes.

    Reviewed by

    Philip Osano

    Research Fellow, Natural Resources and Ecosystems, Stockholm Environment Institute

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