Summary
- Our wellbeing, the wellbeing of our planet and the forces that are driving climate change are interconnected. Integrated approaches to land and natural resource management are needed to adapt, restore biodiversity, and to enhance resilience of people and ecosystems.
- Already, at 1.1°C warming, tree mortality and severity of forest fires and pests are increasing. Yet, at a possible warming of 2°C by 2040, some trees might still have a better chance of survival than annual crops.
- Agroforestry, with its multifunctional properties, provides a sound framework for optimizing synergies to reduce climate risks, adaptation and greenhouse gas emissions mitigation and, at the same time, enhancing biodiversity at the interface of agriculture and forestry. It also addresses the issues of food insecurity, malnutrition, energy insecurity, livelihoods, inequity and social injustice.
- The COVID-19 pandemic, and the increasing conflicts and costs, are paradoxically giving us a unique opportunity to reflect, drive real change, restore our mindsets and inspire and harness the enthusiasm of the public, including the youth, to transform our way of life. We should strive to seize this moment to ensure that societies better recognize the value of trees and urban agroforestry in building resilient green economies.
- There is no single ‘silver bullet’ agroforestry solution, but a synergy of the right mix including: an integrated landscape approach, co-producing context-specific knowledge and management options with people at the centre, enabling government policies, effective partnerships, direct funding support and long-term commitments and stability.
- If synergized, simultaneous pursuit of agroforestry, restoring degraded lands, halting deforestation, and sustainably utilizing forests, can help address the crises facing people and the planet.
Introduction
Climate change is one of the biggest threats to nature and humanity today. The landscape of risk is already changing and is expected to change significantly in the coming decades. Risks are especially high where climate and non-climate drivers jointly cause food insecurity, poverty, social conflicts, land and water degradation, pandemics and biodiversity loss. There is widespread agreement that Africa is facing significant challenges from increasing climate variability. This is despite the fact that it contributes only 4% of global carbon emissions. Many livelihoods, economic activities and energy sources in Sub-Saharan Africa are largely dependent on climate-sensitive natural resources. Scarcity of fuel wood in many rural areas compels farm households to burn manure and crop residues for energy, thus reducing soil fertility. According to the Food and Agricultural Organization (FAO 2022), over 30% of new diseases reported since 1960 are attributed to land-use change and deforestation, which has also been associated with an increase in infectious diseases such as dengue fever and malaria.
Continued land degradation compounded with climate change and a subsequent increase in frequency and intensity of extreme climatic events will have a negative effect on the vitality, productivity, and quality of ecosystems. Loss of ecosystems and their services will have a long-term impact on communities (IPCC AR6). Despite the global goal of achieving zero hunger by 2030, malnutrition remains prevalent and is especially acute in vulnerable regions of the world (Queiroz et al. 2021). According to a recent IPCC report, 3.3-3.6 billion people live in areas that are highly vulnerable to climate change.
The impact of climate change on trees and their ecosystem services
Although it is often difficult to disentangle climate change from other stresses, evidence shows that climate change is contributing to decreased tree growth in the tropics (Zuidema et al. 2022), trees die back from heat and drought stress, and there has been an increase in the number of forest fires, pest and disease outbreaks (Hammond et al. 2022). We found high cocoa tree mortality related to heat and drought stress, plus fungal attacks in Côte d'Ivoire.
A rise in CO2 concentrations is also causing an increase in intrinsic water use efficiency of trees globally (Rahman et al. 2020). The tipping point of this trend, and its repercussions on the hydrological cycle is yet to be fully understood. According to IPCC AR6 (2022), at global warming levels of 1.5°C, about 3-14% of species assessed in terrestrial ecosystems will likely face a high risk of extinction. On the other hand, near term actions that limit global warming to close to 1.5°C would substantially reduce projected losses and will further determine the magnitude and rate of climate change and associated risks beyond 2040. To ensure progress towards attaining the Sustainable Development Goals (SDGs), it is crucial that the negative impacts of climate change on trees and forests, and forest-dependent communities be addressed. Hence, the aim of this paper is to describe the principles, challenges and opportunities of agroforestry in climate change adaptation and its contribution in building the resilience of people and ecosystems.
Fig. 1: Multifunctional properties of Agroforestry
Source: World Agroforestry (ICRAF)
Agroforestry as a climate resilient development path
In most parts of Africa, Asia and tropical America, agroforestry is not new. There are traditional agroforestry practices spanning centuries. Examples include the parkland systems of the Sahel, the Moringa-based agroforestry system in Ethiopia, the Gedo home garden cultural landscapes in Ethiopia, coffee agroforestry systems, Faidherbia albida-based cropping system in Malawi, multistory home gardens in Mt. Kilimanjaro, cocoa systems in Cameroon, rotational woodlots in Kenya, and farmer-managed natural regeneration in the Sahel. Agroforestry is also gaining ground in the global North. For instance, in southern France, where ripening time is now 2-3 weeks earlier than just 50 years ago, some growers are adapting by keeping their traditional varieties from ripening too soon by simply growing trees – “vines among the pines” (Hoffner 2020).
As a result of their diversity, agroforestry systems are more resilient to environmental shocks and the effects of climate change than conventional agriculture (van Noordwijk et al. 2021). Trees serve as safety nets in times of emergency such as natural disasters (e.g., floods and droughts). Trees substantially cool cities. Agroforestry provides a range of other benefits – food and nutrition security, improved health and wellbeing, and livelihoods (Garrity et al. 2010). In addition, homestead agroforestry empowers women and youth. Agroforestry connects habitats and provides corridors for vulnerable species. Depending on the system and local conditions, agroforestry can achieve 50-80% of the biodiversity of natural forests (FAO 2022). By restoring wildlife habitats, it guarantees the balance of ecosystems.
Despite its multiple benefits, adoption of agroforestry has not been widespread in many parts of Africa. Research is required to better understand the challenges and opportunities at local level. Some general principles, from lessons learned so far, are discussed below.
Important lessons learned for transformative climate change adaptation
Building resilience at landscape level
Land degradation and deforestation usually occur due to lack of alternative sustainable livelihoods. Ecosystem degradation, biodiversity loss and poverty are linked; this means that environmental rehabilitation and poverty reduction must be tackled together (Hagazi et al. 2020). The interconnectedness of these factors underlines the value of working across sectors and addressing environmental, social and economic issues in an integrated manner. Landscape includes the physical and biological features of an area, as well as the institutions and people who influence it. In most areas, forests and trees are embedded within a broader landscape influenced by a range of biophysical, social and institutional forces. Working at the landscape level will promote building of resilience of land-use systems, natural resources and people’s livelihoods in a cohesive way, and is more likely to optimize their contributions to the stability and vitality of ecosystems, harness biodiversity and their ability to support societal needs in a sustainable manner (Hagazi et al. 2020; Mbow et al. 2014).
People at the centre
Effective climate adaptation through agroforestry and land restoration is achievable if: decisions are made based on shared visions; implementations are framed with clear action-oriented purposes; and local communities are enabled to articulate their values in ways that can be included in decisions from benefit-sharing to monitoring and evaluation. It is important to identify leaders and key agents who can promote deep social changes. Understanding the dynamics between the different elements (biophysical, social, economic and institutional power dynamics) and engaging local stakeholders in decision-making will help in the development of strategies and actions.
“No silver bullet” agroforestry practice
Agroforestry is not new in most parts of Africa, Asia and America. While important lessons can be learnt from existing traditional practices, scaling up agroforestry will require one to co-produce context-specific data and management options based on traditional, local and scientific knowledge. Selected options should ideally enhance household resilience to shocks. Common desirable traits for climate adaptation in agroforestry include diversification of varieties or species; integrating fertilizer, fodder, fruit, fuel wood and timber tree production with food crops; cultivar improvements (heat- and drought-tolerant species); planting techniques and post-planting care; diversification of on-farm activities; plus, use of clime information and seasonal climate forecasting. It also includes conservation of water resources; enhancement of agrobiodiversity (including bees and pollinators); adapted livestock and pasture management; improved management of pests, diseases and weeds; and promotion of energy efficiency (solar and biofuels) (Hagazi et al. 2020).
Figure 2: Examples of agroforestry systems in Ethiopia a) UNESCO World Heritage Konso Cultural Landscape: dry stone terraces and Moringa-based agroforestry system; b) Homestead agroforestry in Lemo; c) Faidherbia albida-based cropping system in Tigray and d) Gedo cultural agroforestry landscapes.
Restore the mindset first
By 2050, urban areas could be home to two-thirds of the world’s population. Cities provide a global opportunity to advance adaptation and mitigation. Diversifying where and how we grow our food helps reduce the risk of disruption to supplies and cut emissions. It is an opportunity to introduce agroforestry into the fabric of urban life and could bring greenery and sustainable lifestyles closer to home. Opportunities in rural areas for agroforestry range from the homestead to the landscape. Similarly, opportunities for urban farming extend beyond backyards: rooftops, walls, under solar panels (agrivoltaics), informal and refugee settlements. We can draw lessons from traditional agroforestry practices to design urban agroforestry. Of course, urban agroforestry sites can be challenging due to limited space, but we can draw from the option-by-context approach to create agroecosystems that appeal to urban settings.
In addition to the climate crisis, this will address the One Health concept as set out in the WHO Manifesto for a healthy and green recovery from COVID-19.
Science capacity
Although the African continent faces significant challenges from climate variability and change, it has limited scientific capacity to manage their adverse effects (IPCC 2022). Not all smallholder farmers have the capacity neither technically nor economically, to adapt their trees and ecosystems to climate change. There is also lack of basic information on how climate and ecological processes operated in the past, which tree species will be resilient to climate change and how sustainable their future ecosystems will be. In view of these crucial issues, there is need to generate data, knowledge and predictive systems. Evidence-based approaches to matching the right trees and management practices to production systems, ecosystems and microsite conditions are required. There is a need to link indigenous knowledge to modern agroecological knowledge.
Valuing ecosystem services
The way we assign value to nature and environment is misleading. They are usually economically undervalued. For instance, Cuni-Sanchez et al. (2021) found that forests in Africa store around 150 tons of carbon per hectare, but existing guidelines for African mountain forests set the figure at 89 tons. Another aspect which is completely ignored in the global climate change discourse is the role of trees in the hydrological cycle. The Abraha We Atsbeha community in Tigray described the ecosystem benefits of landscape restoration in an interesting way: “Water bank – we spend our time and labour restoring degraded lands upstream, and our ATM machine is downstream through ground water recharge”. This was because the number of shallow wells increased significantly as a result of the rising water table and landscape-level infiltration during the rainy season. As a result, farmers could easily develop hand-dug wells and check dams for growing vegetables and fruit trees through small-scale irrigation practices, which enabled them to cultivate twice during the off-season. The role of trees in modifying micro- and meso-climates and in the hydrological cycle needs to be valued. Instrumental values that judge nature by the human benefits it could generate should be balanced with ‘relational’ values, that go beyond ‘utility’ and express respect and stewardship.
Monitoring and evaluation
This is key to managing tradeoffs and synergies between adaptation and mitigation, ecosystem services, and benefits to avoid maladaptation. Adaptation should not be evaluated only by the number of trees planted, hectares restored or the amount of carbon sequestered. It must be assessed by looking through the community’s eyes, in relation to their expectations, envisioned adaptation pathways and whether it allows them to benefit and protect their land in the long term. New business models in agroforestry in rural and urban settings should reward communities for promoting the resilience and adaptive capacity of their trees, forests and ecosystem services. The system should focus on resilience and adaptive capacity as key indicators (FAO 2022).
Incentives, institutions and governance mechanisms to support resilience
On average, agroforestry realizes profitable returns after 3-8 years. Therefore, offering secure, long-term rights to land, trees and tree products, in exchange for the adoption of good management practices, incentives and strategic investments are required. Empowering and incentivizing local actors, including women, youth and indigenous communities, to play a leading role is also crucial. Long-term political commitment and follow-through across all levels of government, promotion of participatory and innovative approaches, plus collaboration among multiple stakeholders can help in the attainment of consensus for system-wide actions.
Conclusion
We reached 1.1°C of warming in 2021. The goal is to restrict global warming to 1.5°C by 2100, thus ignoring adaptation is not an option. Abandoning adaptation means deserting those most vulnerable to and least responsible for global warming. The IPCC recommends agroforestry as a sustainable solution to addressing the challenge of climate change. Beyond the climate crisis, agroforestry can address the issues of food insecurity, malnutrition and biodiversity loss. Agroforestry in both rural and urban settings is a powerful concept with popular appeal, inspiring diverse people to imagine urban food systems on a wider scale – from homesteads to landscapes, from residential lots to vacant lots to public green spaces. According to FAO (2022), of the 2.2 billion ha of degraded land identified as potentially available for restoration worldwide, 1.5 billion ha may be best suited for mosaic restoration, combining forests and trees with agriculture.
However, to improve the adoption rates of agroforestry, and adaptation objectives, incentives and strategic investments will be required for 3-8 years. Effective adaptation requires more science, better data and bold policies across multiple sectors, plus effective partnerships. Most importantly there is a need for action on the ground. Meaningful action calls for mobilization of finances. It is worth noting that adaptation does not replace mitigation by any means, and vice-versa. Expanding agroforestry and restoring degraded lands must be complemented with halting deforestation and maintaining forests. Otherwise, as warming proceeds, both adaptation and mitigation become more expensive and less effective. Thus, wealthy nations must fund adaptation in the global South. The time for bold climate action is now.
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