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Ecosystem Change

10. Conclusions: main findings

  • 10.1 Finding 1: Ecosystem change in last 50 years
  • 10.2 Finding 2: Gains and losses from ecosystem change
  • 10.3 Finding 3: Ecosystem prospects for next 50 years
  • 10.4 Finding 4: Reversing ecosystem degradation

The Millennium Assessment was carried out in order to better understand the link between ecosystems and human well-being. This process led to four main findings: More...

10.1 Finding 1: Ecosystem change in last 50 years

Over the past 50 years, humans have changed the structure and functioning of the world’s ecosystems more rapidly and extensively than in any period in human history. For instance, more land has been converted to cropland since 1945 than in the 18th and 19th centuries combined. These changes have been made largely to meet rapidly growing demands for food, freshwater, timber, fiber, and fuel. Between 1960 and 2000, the demand for ecosystem services grew significantly as the world's population doubled and global economic activity increased more than six-fold. The demands have been met by both consuming an increasing fraction of the available supply (for example, diverting more water for irrigation or catching more fish) and by raising the production of services such as crops and livestock. This has resulted in a substantial and largely irreversible loss in the diversity of life on Earth. More...

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10.2 Finding 2: Gains and losses from ecosystem change

The changes that have been made to ecosystems have contributed to substantial net gains in human well-being and economic development in most countries. The use of ecosystems through agriculture, fisheries, and forestry has been the basis for development for centuries, providing revenues that have enabled investments in industrialization and poverty reduction. However, actions to increase one ecosystem service often cause degradation of other services, which in turn can cause significant harm to human well-being. Examples include increased risks of non-linear ecosystem changes, loss of natural capital assets, the exacerbation of poverty for some people, and growth in inequalities between groups of people. These problems, unless addressed, will substantially reduce the benefits that future generations obtain from ecosystems. It is difficult to assess the implications of ecosystem changes and to manage ecosystems effectively because many of the effects are slow to become apparent, because they may occur at some distance, and because different stakeholders bear the costs and reap the benefits of changes. Approximately 60% of the ecosystem services evaluated in this assessment (15 out of 24) are being degraded or used unsustainably. For example, capture fisheries and freshwater are now used at levels well beyond what can be sustained even at current demands, let alone at future ones. More...

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10.3 Finding 3: Ecosystem prospects for next 50 years

The Millennium Ecosystem Assessment (MA) developed four scenarios to explore plausible futures for ecosystems and human well-being. In the scenarios, growing pressures on ecosystems during the first half of this century could result in significant growth in consumption, continued loss of biodiversity, and further degradation of some ecosystem services. Most direct drivers of change in ecosystems, such as climate change, overexploitation, and pollution, are likely to remain constant or increase in intensity in most ecosystems. In all four scenarios, these pressures on ecosystems are projected to continue to grow during the first half of the century. The degradation of ecosystem services already poses a significant barrier to the achievement of the Millennium Development Goals. More...

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10.4 Finding 4: Reversing ecosystem degradation

The challenge of reversing the degradation of ecosystems while meeting increasing demands for their services can be partially met under some scenarios involving significant changes in policies and institutions, substantial technological innovations, and increases in the capacity of people to manage local ecosystems and adapt to ecosystem change. However, the actions that would be required to reverse degradation are much larger than those currently taken. Past actions to slow down or reverse the degradation of ecosystems have yielded significant benefits, but these improvements have generally not kept pace with growing pressures and demands. Substitutes can be developed for some ecosystem services, but not for all. However, they are generally expensive and may also have negative environmental consequences.

Ecosystem degradation can rarely be reversed without addressing the five indirect drivers of change: population change (including growth and migration), change in economic activity (including economic growth, disparities in wealth, and trade patterns), socio-political factors (ranging from the presence of conflict to public participation in decision-making), cultural factors, and technological change. Many options exist to conserve or enhance specific ecosystem services in ways that reduce negative trade-offs or that provide positive synergies with other ecosystem services. More...

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