- The use of resources such as food, water, and timber has increased rapidly, and continues to grow, sometimes unsustainably.
- Human interventions have led to changes in the regulation of climate, disease, and other ecosystem processes.
- The use of ecosystems for recreation, spiritual enrichment, and other cultural purposes is growing. However, the capacity of ecosystems to provide these services has declined significantly.
- In the past, increases in the supply of resources were often achieved despite local limitations by shifting production and harvest to new, less exploited regions. These options are diminishing, and developing substitutes for services can be expensive.
- When humans modify an ecosystem to gain something, it often has negative effects on other components of ecosystems, leading to trade-offs. For instance, increased food production tends to bring about reductions in biodiversity. Changes in
biodiversity at a particular location affect the ability of the ecosystem to supply services and to recover from disturbances. However, conserving or enhancing particular components of an ecosystem, for instance creating an urban park, can
also lead to positive synergies improving a variety of services.
- Ecosystem services, particularly food production, timber and fisheries, are important for employment and economic activity. Intensive use of ecosystems often produces the greatest short-term advantage, but excessive and unsustainable use can lead to losses in the long term. A country could cut its forests and deplete its fisheries, and this would show only as a positive gain to GDP, despite the loss of capital assets. If the full economic value of ecosystems were taken into account in decision-making, their degradation could be significantly slowed down or even reversed.
- Some ecosystem changes such as increased food production have helped hundreds of millions of people out of poverty, but also have negative effects. Degradation of ecosystem services is harming many of the world’s poorest and most vulnerable people, and is sometimes the main factor causing poverty. Poverty in turn tends to increase dependence on ecosystem services. This can lead to additional pressure on ecosystems and a downward spiral of poverty and ecosystem degradation.
- Levels of poverty remain high, and over one billion people have an income of less than $1 per day. Most of these people are very dependent on ecosystems, because they support themselves mainly through agriculture, grazing, and hunting. The
regions facing the greatest developmental challenges tend to be those having the greatest ecosystem-related problems. These include some parts of Africa, Asia and Latin America. More...
- Natural or human-induced factors that change ecosystems are called drivers. Habitat change and overexploitation, for instance, are direct drivers that influence ecosystem processes explicitly. Indirect drivers affect ecosystems by influencing the direct drivers. The main indirect drivers are changes in human population, economic activity, and technology, as well as socio-political and cultural factors. For example, world population has doubled in the past forty years, with most of the growth taking place in developing countries. Pressures on ecosystems have grown in absolute terms, but the growth has been slower than GDP growth. This is due to changing economic structures, increased efficiency, and use of substitutes for ecosystem services.
- Important direct drivers include: habitat change, climate change, invasive species, overexploitation, and pollution. Habitat change occurs, for instance, when the area of land used for agriculture or cities is expanded. World climate has already changed and continues to change, affecting temperature, rainfall, and sea levels. Commercially exploited fish stocks are probably at a historical low. Intensive use of fertilizers has polluted ecosystems with excessive amounts of nutrients. Most direct drivers of degradation are currently staying constant or growing in intensity.
francis1897 answered the question on February 28, 2023 at 05:11