Climate change poses a critical threat to nature, wildlife, and people around the world.
Human activities such as deforestation, livestock farming, and the burning of fossil fuels have contributed to an increase in greenhouse gas emissions while limiting the ability of ecosystems to sequester carbon from the atmosphere.
Nature-based solutions, on the other hand, can play a vital role in storing and removing carbon, protecting natural habitats, and enhancing community resilience in the face of the many impacts of climate change.
This article provides a comprehensive overview of nature-based solutions—including the many co-benefits, how they support climate change mitigation, and the actions required to implement them on a global scale.
What are nature-based solutions to climate change?
Nature-based solutions (NBS) are actions to reduce and remove harmful greenhouse gas emissions and protect, sustainably manage, and restore ecosystems to fight climate change.
By enhancing the ability of ecosystems to sequester carbon dioxide (CO2), nature-based solutions can also help address current societal challenges, such as threats to food and water supplies, hazards to human health, and destruction from extreme weather and natural disasters.
Nature-based solutions, such as conserving marshes and forests or practicing sustainable agriculture, also play a vital role in supporting biodiversity. For instance, planting mangroves in coastal wetlands experiencing erosion and flooding can help reduce the impact of storm surges and provide a home for birds, marine life, and plant life.
Forestation efforts
Flourishing forests are important because they can store CO2 for long periods, thus removing it from the atmosphere. Forestation is the process of helping damaged forests recover or growing new trees on previously unforested land.
Forest restoration involves helping return forest structure, ecological processes, and biodiversity to its more natural state. This can be accomplished by controlling invasive species, maintaining diversity of trees, or pruning underbrush to support tree health.
Reforestation is the regeneration of tree cover in areas that recently experienced loss or total destruction via pest or disease, wildfire, or the clearing of land. It can either comprise plotting new trees or allowing for natural re-growth via seeds from surviving plants or those carried in by wind and wildlife.
Afforestation involves planting new trees on land that has been unforested for an extended period. This could be in an area that has experienced desertification or land that was previously used for agriculture, livestock, or industrial purposes.
Ecosystem restoration
Ecosystem restoration involves rejuvenating ecosystems that have been damaged or destroyed and conserving those that are currently intact. It is important because healthy ecosystems with robust biodiversity can store more carbon and produce more fertile soil.
By 2030, the restoration of 350 million hectares of degraded land and water ecosystems could remove 13 to 26 gigatons of greenhouse gases from the Earth’s atmosphere. Everyone from governments and businesses to communities and individuals can undertake restoration projects.
The types of ecosystems that can be restored include urban areas, mountains, freshwaters, forests, grasslands, shrublands, and savannahs, as well as the three environments below.
- Farmlands: Sustainable agriculture practices that farmers can implement include reducing tillage and adopting natural forms of fertilizers and pest control instead of relying on practices that increase soil carbon. Other initiatives include crop rotations, planting more diverse crops such as trees, and allowing livestock to graze on cropland after harvest to help rebuild organic carbon stores and enhance soil fertility.
- Peatlands: These ecosystems are valuable carbon sinks that help control water supplies, prevent droughts and floods, and produce food, fuel, and rare plants and animals. They are being drained and burned around the world for infrastructure development, agriculture, and fossil fuel exploration, which in turn releases carbon. Conserving existing peatlands and re-wetting and restoring drained areas is critical to reducing greenhouse gas emissions and lessening the impact of global warming.
- Oceans and coastal areas: Climate change is damaging coral reefs, mangroves are being cleared for fish farming, and millions of tons of plastic waste are harming ocean creatures. Overfishing, nutrient pollution, and the discharge of untreated wastewater are causing additional damage. The restoration of seagrass meadows, transplantation of key marine species, implementation of sustainable fishing, treatment of water pollutants, and policies to prevent dumping of plastics and other waste are essential to preserving these ecosystems.
Green infrastructure
Green infrastructure systems help to improve resilience and the capacity to manage stormwater in urban areas. The runoff from stormwater carries heavy metals, trash, bacteria, and other pollutants through sewers and into local waterways, while heavy rain can cause flooding that destroys property and key infrastructure.
The purpose of green infrastructure is to filter and soak up stormwater where it falls. The Water Infrastructure Improvement Act of 2019 defines green infrastructure as "measures that use plant or soil systems, permeable pavement, or other permeable surfaces or substrates, stormwater harvest and reuse, or landscaping to store, infiltrate, or evapotranspirate stormwater, and reduce flows to sewer systems or to surface waters."
Green infrastructure elements can be implemented at the community, city, or regional watershed level to help supply cleaner water and air, provide flood protection, and support diverse habitats and green spaces.
Examples include:
- Creating green alleys, streets, and parking
- Constructing rain gardens and urban tree canopies
- Installing permeable pavements
- Disconnecting residential and commercial downspouts
- Conserving natural spaces and wetlands
Natural carbon sequestration and climate change mitigation
The nature-based solutions mentioned make it easier for ecosystems to capture CO2 from the air, sequester it in soil, sediments, plants and water, and remove it from the atmosphere. Natural carbon sinks such as forests, wetlands, and coastal ecosystems absorb almost one half of the excess CO2 resulting from human activities.
The ocean is likely the world’s largest carbon sink, absorbing 25% of all CO2 and capturing 90% of the excess heat produced by carbon emissions. Parts of the ocean that are cooler and more nutrient-dense (such as polar regions) can sequester more CO2 than warmer waters. Aquatic organisms such as plankton and algae also absorb CO2 and release oxygen back into the air via photosynthesis.
Grasslands, forests, and plants also sequester carbon emissions in the atmosphere through the same process and store it in biomass, deadwood, leaves, roots, and soil. Soil sequesters carbon as soil organic matter (SOM), which comprises microbes, carbon compounds, and carbon-related minerals that can potentially be stored for millennia. To that end, peatlands are a particularly powerful soil-based carbon sink because their wet environment prevents plants from fully decomposing and releasing CO2 into the atmosphere after they die.
There are limits to how much carbon natural environments can absorb. For example, when carbon dioxide reacts with seawater, it dissolves and is replaced by carbonic acid, which can disrupt the ocean’s chemical balance and negatively impact marine life. However, nature-based solutions like conservation and reforestation can help support and balance natural carbon sequestration.
Co-benefits of nature-based solutions beyond climate change
As it pertains to the environment, the key benefit of NBS is the ability to conserve and expand ecosystems to promote healthier wildlife habitats and protect biodiversity. For example, watershed and shoreline initiatives can give plants and animals more space and support aquatic and wildlife habitats by enhancing water quality.
NBS can also help reduce damage and enhance the ability of humans to bounce back from disasters such as flooding, drought, heat waves, hurricanes, and forest fires.
Additional potential social, health, and economic advantages of NBS include:
- Improved water quality: NBS can help filter pollutants from stormwater runoff, reduce the volume of pollutants entering bodies of water, lessen the untreated sewage that enters waterways, and lower the volume of rain flow entering combined sewer systems.
- Cleaner water supplies: New York City has high-quality tap water because it invested in NBS to conserve and restore the land surrounding its 19 reservoirs, which helps keep polluted run-off away from the water supply.
- Enhanced air quality: Parks, trees, and other plant-based NBS can absorb and filter greenhouse gases and reduce air temperatures and smog to improve overall air quality.
- Increased property values: Properties near parks or with more landscaping tend to have a higher value than those that don’t. As parks increase in size, so does their impact on property values.
- Green job opportunities: Green stormwater infrastructure can create new jobs in sectors including paving, construction, landscaping design, and emerging industries.
- Improved public health outcomes: NBS that enhance air and water quality help to reduce human exposure to toxic pollutants, while cooler temperatures during the summer lessen the risk of heat-related illness. The addition of green spaces for recreation also provides greater opportunities for activities that boost physical health, social engagement, and emotional well-being.
Requirements for implementing NBS
For nature-based solutions to be most effective in the fight against the climate crisis, it’s essential that they receive support and funding from public and private sectors on the domestic and international levels.
Policy support and investment
On Earth Day 2022, President Biden issued an executive order recognizing the importance of nature-based solutions in addressing the climate crisis and strengthening communities and local economies.
In November 2022, the White House submitted a Nature-Based Solutions Roadmap to the National Climate Task Force that called for five strategic areas of focus, including updating policies, providing funding, leading with federal facilities and assets, training the workforce, and prioritizing research and innovation to advance NBS.
The plan also advances NBS in support of the administration’s commitment to:
- Reduce greenhouse gas emissions 50-52% below 2005 levels by 2030
- Conserve at least 30% of US lands and waters by the same year
- Increase community resilience to extreme weather and other results of climate change
In addition to federal policies and funding to support the implementation of nature-based solutions, strong partnerships with governments at the local and state level, community organizers, conservation non-profits, businesses, hazard mitigation officials, and individuals and families are critical.
According to global models, approximately $2.4 trillion per year through 2035 is required for supply-side energy system investments alone to limit global warming to 1.5°C. Financing for climate mitigation typically stems from public funds, development finance institutions, state-owned enterprises, financial institutions, and private corporations and individuals.
To successfully implement nature-based solutions on a large scale, it will be critical to incentivize more private sector investment. Examples of incentive-based programs include rebates and financing programs, grants, public-private partnerships, development or redevelopment incentives, banking or credit trading programs, local fee or tax rebates, and community awards.
Scaling up NBS to achieve global climate goals
The Paris Climate Agreement is an international commitment to keep global warming below 2°C and pursue initiatives to limit warming to 1.5°C. Any increase above 1.5°C may create greater risk for extreme flooding, rising sea levels, droughts, wildfires, and loss of ecosystems.
According to a report by the International Federation of Red Cross and Red Crescent Societies (IFRC) and the World Wildlife Fund (WWF), scaling up NBS could potentially protect society from some of the most severe results of climate change by:
- Providing up to 30% of the solutions required to meet emissions targets under the Paris Climate Agreement
- Saving developing countries at least $393 billion through 2050 by reducing the intensity of climate and weather-related hazards by 26%
- Significantly reducing the number of people who require international humanitarian assistance
To support successful global implementation of nature-based solutions, the report recommends:
- Funding research to close the knowledge gap on what comprises effective and sustainable NBS (including its limitations)
- Close capacity and funding gaps at all levels
- Align international and national policy to promote standardized strategies for disaster risk reduction
- Promote models of engaging local communities and Indigenous Peoples in the planning and implementation of NBS
Examples of successful NBS
Below are three examples of nature-based solutions that have helped reduce the impacts of climate change, restore essential ecosystems, and fortify local communities.
- Mangrove reforestation in Mozambique
Community members in areas surrounding the Limpopo River Estuary maintain a mangrove nursery, plant seedlings, and monitor and protect reforested areas. As a result of their efforts, they have improved flood protection, lessened salt intrusion on farming land (increasing food security), shifted to more sustainable livelihood practices and restored over 100 hectares of mangroves. - River restoration in Scotland
The Eddleston Water project uses natural flood management techniques, including tree planting, river re-meandering, and the development of new wetlands, to slow the speed and damage of floodwaters and create new habitat for spawning salmon. Consequently, this NBS has reduced the risk of downstream flooding by 30%. - Reforestation and agroforestry in the Amazon
The Instituto Raoni teaches the Kayapó Indigenous people (women in particular) to combat deforestation and protect rich biodiversity in the Amazon through sustainable agriculture and agroforestry. Their work has restored 13 hectares of degraded land, reduced reliance on fire in farming to decrease carbon emissions, and strengthened fair-trade production chains that include non-timber forest products to generate income.
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Additional sources
https://www.lse.ac.uk/granthaminstitute/explainers/what-are-nature-based-solutions-to-climate-change
https://www.americanforests.org/article/what-is-reforestation-and-forest-restoration/
https://www.american.edu/sis/centers/carbon-removal/fact-sheet-forestation.cfm
https://www.epa.gov/green-infrastructure/what-green-infrastructure
