Ecological restoration—the rehabilitation of degraded landscapes—is a bright spark in the effort to achieve sustainable development. If given a chance, damaged ecosystems can recover rapidly. Research shows that forest ecosystems recovered in 42 years on average, while ocean bottoms recovered in less than ten years. Ecosystems affected by either invasive species, mining, oil spills, or trawling recovered in as little as five years.1 The following case studies from China and Rwanda demonstrate the potential of ecological restoration for environmental health, local poverty alleviation, and sustainable development.
Ecological Restoration in Practice: China and Rwanda
The Loess Plateau in northwest China is home to more than 50 million people. Centuries of uncontrolled grazing, deforestation, and subsistence farming caused widespread erosion and environmental degradation, and plunged the region into poverty. Moreover, the erosion of the plateau led to silting of the Yellow River. (The Yellow River basin is home to one in nine—over 130 million—Chinese people, and most depend, directly or indirectly, on the river for their livelihood.)2 A study conducted by China’s Ministry of Water Resources with the assistance of the World Bank in the early 1990s found that restoring ecological function on the plateau would be less expensive than continuously dredging the river. It also found that, on much of the land, the ecological functions, such as soil retention, were worth more than the profits from continuing to exploit what was already a much-degraded region.
This study led to the creation of the U.S.$240 million, ten-year Loess Plateau Watershed Rehabilitation Project in 1995,2 which set 35,000 square kilometers of land aside for restoration and sustainable agriculture. The project created many thousands of jobs for the poor local inhabitants in terracing and building small dams and sediment traps to slow runoff. It also encouraged the regeneration of grasslands as well as the planting of trees and shrubs on previously cultivated slopes to reduce erosion.
The outcome provided many useful lessons. Sediment flow into the Yellow River was reduced by more than 53 million tons just during the life of the project. A network of small dams stores water for use by towns and farmers when rainfall is low, and reduces the risk of flooding. Replanting and bans on grazing increased the perennial vegetation cover from 17 percent to 34 percent. Local food supply increased. More than 2.5 million people were lifted out of poverty. Farmer incomes rose from about U.S.$70 per year per person to about U.S.$200.3 In addition, the project produced substantial benefits downstream as a result of reduced sedimentation, and globally through carbon sequestration.2
The Loess Plateau’s restoration helped to inspire the government of Rwanda to adopt its own restoration policy in February 2011. Rwanda is one of the world’s poorest and most densely populated countries, where 85 percent of the population practices subsistence farming on degraded lands. Poor forest management and land-use conflict led to a rapid loss of the country’s forest cover in the 1990s. Its new Forest Landscape Restoration Initiative aims to reverse degradation of soil, water, land, and forest resources by 2035, and to use ecosystem restoration as a way to create jobs.4
The momentum in Rwanda has manifested in ambitious plans to enlarge forest coverage, restore biodiversity, reduce the risk of flooding and drought, ensure food security, and reduce dependence on petroleum by developing alternative renewable energy sources. In an innovative partnership with the Smith School of Enterprise and Environment, with support from the Climate Development Knowledge Network, Rwanda’s Cabinet approved the Rwanda national strategy for climate change and low carbon growth in December 2010.
As seeing is believing, soil scientist and filmmaker John D. Liu has recorded the progress of the Loess Plateau transformation over 15 years, and is currently documenting the Rwandan initiative.5
According to the International Union for the Conservation of Nature (IUCN), there are approximately 1.5 billion hectares of land worldwide with potential for forest landscape restoration. Asia and Africa hold the greatest promise: each has about 500 million hectares available for restoration without impacting current agricultural activities.4 Restoration also offers opportunities for the most polluting industries to mitigate their ecological footprint.
Take the energy sector. With rising global population and urbanization, energy demand will inevitably increase. The International Energy Agency (IEA) estimates the world will need to invest U.S.$38 trillion in energy-supply infrastructure to meet the projected demand by 2035.6 However, the IEA acknowledges the window for limiting the global average temperature increase to two degrees C is closing fast.6
Ecological restoration can provide a way forward. Companies in the energy sector already have to restore the environment where they have caused damage by extracting resources, but they could do more: they could look to offset their carbon emissions through large-scale ecological restoration.
It is already accepted that stopping deforestation and forest degradation is vital to tackling climate change, as those activities contribute 15–17 percent of all greenhouse gases. It only takes a small stretch of the imagination to see ecological restoration in the same light. If the principle is accepted, then the next step is to find ways to fit projects like the Loess Plateau and Rwanda’s effort into an overall mitigation framework, especially for the energy and mineral mining sectors.
Large-scale projects, like the examples above, require the right government policies and possibly international funding, as well as deep societal collaboration. The Loess Plateau Watershed Rehabilitation Project, for example, involved many layers of bureaucracy for design and implementation, and Rwanda’s Forest Landscape Restoration Initiative is a collaboration between the Rwandan government, IUCN, the Secretariat of the UN Forum on Forests, and many others. But the payoffs for these efforts can be substantial: For example, the IUCN estimates that restoring 150 million hectares of lost forests and degraded lands worldwide—the goal set forth by the Bonn Challenge Ministerial Roundtable in September 2011—would be worth U.S.$85 billion per year to national and global economies. We can hope that, with examples like the Loess Plateau and Rwanda to guide us, other nations will see that being good to the environment can be good for people as well.
The concepts behind ecological restoration can also be applied to urban jungles. The need is great: already one-half of the world’s population lives in cities and, by 2030, city-dwellers will make up 60 percent of the global population.7 While cities cover only about 1 percent of the land on earth, they have an outsized ecological footprint.
Many of the urban areas that will exist in 2030 have not yet been built, and some of what exists today will be replaced. As we remake our cities (and build new ones), there are many sustainable development opportunities that should not be missed. For example, we must lower the urban heat-island effect (the byproduct of our massive use of concrete and asphalt to create dark-colored rooftops and pavements) and reduce water use, since many cities have to import water from their surrounding regions, which carries a high cost both to consumers and the ecosystems that supply the water.
Projects in Los Angeles are transforming neighborhoods into sustainable ecosystems that function like natural forests, where residents plant and care for trees and incorporate forest-mimicking technologies into their urban landscape. In these neighborhoods, trees shade walkways, streets, buildings, and recreation areas to reduce energy and water use. Native and drought-tolerant plants and grasses reduce the need for irrigation. Permeable paving replaces hard asphalt surfaces and allows rainwater to soak into the ground, thus reducing flooding and runoff into waterways. Swales—human-made trenches planted with native vegetation—slow the flow of rainwater, and raised berms create sunken gardens that trap rainwater and let it seep into the ground. Rain barrels or cisterns store rainwater for use in dry seasons.8
The Elmer Avenue Neighborhood Retrofit Project is a good example. This small neighborhood in Los Angeles’ San Fernando Valley used to suffer from flooding during the rainy season. Retrofitting the storm drains took the street off the city’s water grid. Now, all the rainwater that falls on Elmer Avenue and some adjacent streets is captured in a large underground infiltration gallery and allowed to soak into the ground. This system mimics a natural watershed, directing water into underground aquifers, thereby increasing local water supply.8