— Nature Based Solutions—

The current carbon stock in the world’s forests is around 860 gigatonnes of carbon (Pan et al. 2011). From 2001-2019 there was a 9.7% decrease in global tree cover, releasing 105 gigatonnes of CO2 (equivalent to 29 gigatonnes of carbon) (Global Forest Watch 2020). It is critical to end deforestation and keep carbon locked up in forests rather than letting it enter the atmosphere. This means eliminating deforestation from supply chains, which includes displacement of deforestation elsewhere, e.g. if one crop displaces another, the demand for which is then met by deforestation (Lambin et al. 2018). Intact forests also continue to sequester carbon – forests globally together currently do this at a rate of about 1.1 gigatonnes of carbon per year (Pan et al. 2011), although this carbon sink is gradually saturating (Hubau 2020).

Restoring forests, improving management of existing forests, and growing trees on degraded or agricultural land, also has great potential as a carbon sink. As trees and other forest plants grow, they absorb CO2 from the atmosphere and store it in living plants, dead organic matter and soils. Regrowing natural forest can sequester carbon at an estimated rate of 3.16-3.58 megatonnes of carbon per hectare per year (Cook-Patton et al. 2020; Griscom et al. 2017). However, forests are not the only carbon-rich ecosystem, and we must restore more ecosystems than just forests if we are to achieve the maximum climate change mitigation and biodiversity benefits (Strassburg et al. 2020).

Protecting and restoring forests is also of great value for adapting to climate change, such as by increasing water quality and availability, reducing flooding, preventing landslides and providing food for times of shortage (Chausson et al. 2020). Forest stewardship also supports livelihoods of people – 86 million green jobs are currently provided by forests, and 90% of people living in extreme poverty are dependent on forests for part or all of their livelihoods (FAO 2020). Furthermore, forests are crucial havens of biodiversity – collectively, they are estimated to be home to about 80% of plant and animal species on land (FAO 2020), with tropical forests supporting around two-thirds of land species, despite covering under 10% of Earth’s land surface (Giam 2017).

Agricultural management utilising ecological concepts and components of natural ecosystems can increase carbon sequestration aboveground and in soils. For example, agroforestry – integration of trees into farmland – enhances carbon sequestration rates of croplands or pasturelands, whilst boosting biodiversity (Nair et al. 2009). Agroforestry is also often more profitable than intensive plantations, due to lower costs of management and higher market prices for products (Jezeer et al. 2017).

Other forms of nature-based agriculture that increase carbon sequestration include addition of organic material to soil, reduced tillage and diversification of crop and non-crop species on farmland; these have the additional benefits of enhancing pest control and pollination, and improving soil fertility and nutrient cycling. Evidence is growing that agricultral practices that embrace biodiversity, on average, increase or maintain crop yields (Tamburini et al. 2020).

Nature-based farming has even been shown to decrease the vulnerability of farmers to the effects of the COVID-19 pandemic. In Guatemala, planting multiple crops amongst each other, sharing seed banks to increase genetic variety, coordination of farming at the community level, and payments for forest management from the government, gave these communities insurance food and savings. This increased their ability to cope when transport was restricted due to the pandemic.

Peatlands are highly efficient carbon sinks, because anoxic conditions prevent decomposition of organic matter, meaning carbon can be locked up for millenia. Peatlands cover 3% of the Earth’s land surface, but account for 21% of global soil organic carbon (Leifeld and Menichetti 2018). Therefore, protecting these existing stores, which can continue to sequester carbon in perpetuity, is critical (Rydin and Jeglum 2006). In addition, 10% of peatlands are degraded due to draining or mining, converting them into sources of carbon. Restoring degraded peatlands by rewetting can turn these sources into sinks, providing a  highly cost-effective climate change mitigation strategy , whilst also benefitting biodiversity and still providing income through paludiculture (agriculture on peatlands).