Tree planting is capturing the minds of those who look for fast climate action. Earlier this month, the Ethiopian Government announced a new world record: thousands of volunteers planted 353 million trees in one single day. This came shortly after a team of scientists identified suitable places in the world where up to 1 trillion new trees could be planted. Such a massive effort could absorb about 20 years’ worth of global greenhouse gas emissions. And on 8 August 2019, the Intergovernmental Panel on Climate Change launched a Special Report on the importance of land use for the climate. About 23 per cent of all emissions come from the agriculture, land use and forest sector. The Intergovernmental Panel on Climate Change outlines land management opportunities with benefits for food security, biodiversity, and the climate, such as agroforestry.
The growing enthusiasm for forests and trees is a good thing. Ecosystem restoration will be critical in turning the tide against climate change, and achieving the Sustainable Development Goals. But we need to be mindful of some pitfalls lurking along the way. We have learned valuable lessons over the past decades in afforestation and other restoration projects across dozens of countries. A few basic principles outlined by the Global Partnership on Forest and Landscape Restoration can help us to reduce costs and minimize future risk as the world embraces the need to plant more trees.
Stop the bleeding
The first rule for ecosystem restoration is to stop the further destruction of forests, wetlands, and other critical ‘green infrastructure’. Conserving natural habitats is always cheaper than restoring it later.
Most new trees do not need to be planted
Most ecosystems in the world have remnant seeds in the soil and natural regrowth can be cheaper and more successful than tree planting. The most cost-effective type of restoration is to work with the forces of nature. For example, across the Sahel, a successful and fast landscape restoration technique is called ‘farmer-managed natural regeneration’. It uses the existence of remnant root stocks below the surface, where the trees above ground have disappeared long ago. Farmers nurture those roots and trees back to life. The results are stunning—within a few years, large trees dot the surface of the once barren and dry savannah, bringing back water, productivity and life.
We don’t need to reinvent the wheel
There is already an impressive body of knowledge on which trees to plant, when and where. Under the Bonn Challenge, a global restoration goal initiated by the International Union for Conservation of Nature and the Government of Germany, 59 governments, private associations and other entities have pledged to bring 170 million hectares into restoration by 2020, and 350 million by 2030. Dozens of countries have already detailed maps of where the best restoration opportunities can be found, and how to restore forests and landscapes. Usually, indigenous tree species are preferable, but in a rapidly changing climate, we need to keep in mind that the natural ranges of trees are shifting.
Social inclusion is essential
Forest and landscape restoration is mostly about social transformation, rather than technological solutions. However, this transformation is hard work and requires patience. It is tempting to just stick a few tree seedlings in the ground and hope for the best, but real restoration across an entire landscape is the work of years or even decades. Large-scale restoration successes such as the Shinyanga landscape in Tanzania or the Loess Plateau in China have shown that results of well-planned restoration can yield very high returns for society over a long time.
We must remove the bottlenecks
Some ingredients for success are essential, and their availability varies across countries. The most important one is political will. Fortunately, political will is now growing as protests for more climate action are spreading. Another major ingredient is clarity over ownership and management rights. The estimated 1 billion smallholder farmers in the world will be key. We need to empower them, and give them access to the tools and the finance for improved farming, such as agroforestry. A third key ingredient is availability of a variety of high-quality tree seedlings, in particular for planting trees on farms.
Finally, perhaps the most critical ingredient are massive public and private investments into land restoration. We need to achieve a similar trajectory for a shift in agriculture and forestry as is happening in renewable energy. And just like the shift in renewables, it will take a massive push from both public and private actors to establish restoration as a new financial asset class. It is estimated that every dollar invested in ecosystem restoration can yield more than US$10 in return through ecosystem services. Fortunately, we see growing interest from the finance industry to invest in ecosystem restoration and regenerative agriculture.
Ecosystem restoration and other nature-based climate solutions will be highlighted at the UN Climate Action Summit on 23 September. And the UN General Assembly has just proclaimed a UN Decade on Ecosystem Restoration from 2021 to 2030. With the right approach, we can make the conservation and restoration of ecosystems, including the planting of billions of new trees, a major step in building the sustainable future we all want.