According to the Food and Agriculture Organization of the United Nations (FAO) 2020 report on “The state of the World’s forests”, the planet has lost 178 million hectares of forest between 1990 and 2020; an area about the size of Libya. Forest loss is primarily the consequence of agricultural expansion, unsustainable industrial timber extraction and fires often associated to infrastructure and logging site development. Trees are composed of about a quarter carbon dioxide that is causing global warming. When they fall down or burn, they release about four times their weight in carbon.

Forestry and agriculture account together for 24% of Greenhouse gas (GHG) emissions making deforestation an important contributor to climate change. At the current rate of destruction, the world’s rainforest could completely disappear within 100 years. The effects of deforestation are serious but not irreversible. Resolutions such as managing forest resources or agroforestry are already being made to tackle deforestation’s environmental impacts. We are dedicating this article to explain why these efforts are such an important factor in the fight against climate change.

Natural forests: rich and valuable ecosystems

Natural forest is a multi-layered vegetation unit that is composed of indigenous trees. The world’s forests are mostly known as the “Earth’s lungs” as they absorb enormous amounts of carbon dioxide. Thanks to photosynthesis, trees use the sun and carbon dioxide present in the air as energy sources to produce the food they need. Overall, natural forests can store up  40 times more carbon than a plantation that is harvested every decade. Forests are critical for the climate in general as they maintain rainfalls and shield strong winds. The trees’ foliage keeps the continents from desertification through rainfall recycling. The study “Rainforest-initiated wet season onset over the southern Amazon” explains that the process is called “transpiration”. Plants and trees release water vapor from pores situated below their leaves which creates clouds just above the canopy. These clouds then drop rain and warm the atmosphere causing circulation. The circulation is what brings more moisture from the ocean by shifting wind patterns.

The trees that composed a forest are crucial in stabilising the soil as well. They increase the soil’s ability to absorb and retain water, produce nutrients for plants, maintain high levels of organic matter in the soil, and moderate soil temperatures. In short it maintains what is essential to life on Earth. The state of soils largely depends of the land’s vegetative cover. Without it, the soil begins to crumble and can offer no protection against the ravage of the wind and rain.

Forests are not only made of trees; many different species of plants and animals reside in the soil, understorey and canopy. Forests are indeed home to an incredible biodiversity and provide habitats for an estimate total number ranging from 3 million to 100 million species. Plants, fungi, vertebrate and invertebrate species and other organisms represent half of all terrestrial species. The soil microbes, pollinators and saproxylic beetles are very important actors in maintaining the healthy functions of forests through a decomposition process and nutrient cycling for example. Thanks to the seed dispersal action, mammals and birds intervene in the forest ecosystem structure.

Moreover, forests support indigenous traditions and provide jobs. Local communities and Indigenous people manage almost a quarter of the world’s lands, that is 80 percent of the Earth’s biodiversity including some of the most intact forests. According to the United Nations (UN), more that 1.6 billion people rely on forests to some extent for their livelihoods using derived products for food, shelter, energy, medicine or income generation. Ten million people are directly employed through forest conservation and management.

Reforestation: a real cause for hope in the climate fight

The act of reforestation is the process by which an area that has suffered the removal of trees and vegetation has its native trees restored. Currently, this is understood as being one of the most cost-effective ways of fighting climate change, as trees are natural carbon “sinks”.

For all the above reasons, reforestation is crucial in order to protect biodiversity, manage water or alleviate poverty in low-income regions. If half a trillion of trees were planted, we could capture about 205 gigatons of carbons and decrease atmospheric carbon by about 25%. The International Panel for Climate Change (IPCC) suggests that boosting the total area of the world’s forests, woodlands and woody savannahs could store around ¼ of the atmospheric carbon necessary to limit global warming to 1.5C above pre-industrial levels.

Currently, global forests and trees absorb around 30% of the world’s carbon dioxide, but the rate of deforestation is increasing around the globe, with 18 million acres lost every year. Many degraded lands are good candidate for reforestation and could provide cleaner water, cleaner air, flood control, and more fertile soils. The Atlas of Forest Landscape Restoration Opportunities registered every zone on the planet worthy for forest restoration. Reforestation can either be inexpensive and as simple as abstaining from burning grazing land to allow forests to regenerate naturally or can require planting trees and long-term care as they grow. Different methods and techniques are adopted around the world to replenish forests:  


The afforestation is the establishment of a forest in an area where there was no previous tree cover. This technique is described as the most technically simple of the “negative emissions technologies” (NETs)1. A study by Yosef and al. (2018) found that afforestation in arid areas can enhance rainfall and carbon sequestration potential by boosting evapotranspiration and surface cooling. It is estimated that the carbon sequestration potential in semi-arid zone can be about 10% of the global carbon sink of the land biosphere. However, if badly managed, afforestation on a large scale can have significant environmental impacts. The first issue is regarding the large-amount of land-use change and the application of nitrogen fertilisers. The production of this fertiliser releases nitrous oxides, a group a GHG, along with CO2 which participates in global warming. Additionally, new trees take many years to grow and will not be able to provide the absorption of carbon straight away.

1a variety of methods that aim to limit climate change by removing CO2 from the air.


Agroforestry is a land management approach which involves planting trees in farms in order to give farmers healthier soil and higher yields. It increases wildlife, boosts livestock welfare, manages water flow and contributes to climate change mitigation. The benefits of the technique are due to the symbiotic relationship between the tree and its surrounding. The tree roots are releasing into the soil the needed carbon. The roots cycle nutrients and prevent the soil from erosion. However, the trees need to be planted in a certain way: from north to south to minimise shading. Pollen and nectar species are planted beneath them to attract pollinators vital for farming.

Examples of key goals that have been implemented in the forest’s restoration

The Bonn Challenge is aiming to restore 150 million hectares of damaged landscapes and forest lands by 2020.

The United Nations Strategic Plan for Forests wants to “the loss forest cover worldwide through sustainable forest management, including protection, restoration, afforestation and reforestation”.

The Aichi Biodiversity targets the restoration of at least 15% of degraded ecosystems by 2020.

Reforestation and its downside effects

 While there is a prominent potential for using reforestation, agroforestry and afforestation as mitigation tools, several important factors need to be considered. Forests are complex ecosystems and adapted to the land they grow on. In contrast, their management is often simple and counterproductive, handled by economic systems and bureaucrats. Successful forest restoration requires much greater involvement and care. If badly managed, reforestation can result in outright environment consequences. From there, two situations must be considered: deforestation has to stop, and restoration program should primarily focus on turning degraded lands into natural forests.


Many countries engaged to the International Bonn Challenge have been backing monoculture farms and counting trees that will be logged within years for wood, product or fuel. On the total planted trees, only 34% were part of the “natural forest”. Nations are following three main approaches to improve the tree cover of the planet. One of them is converted marginal agricultural lands into plantations of valuable trees like Eucalyptusfor paper or Hevea braziliensis for rubber. This is the most popular restoration plan and 45% of commitments involve planting tree monocultures that are economically profitable.

The reforestation program “Grain for Green” also illustrates the lack of knowledge and anticipation. Launched by China in 1999 in response to flooding along the Yangtze River, 99% of all trees planted ended up being monoculture plantations.

A research led by Princeton University has found that the program has failed to restore biodiversity from native forests’ levels. The researchers highlighted the necessity of planting native trees and mixed forests to provide a better outcome for the biodiversity.

Sadly, such forests are an issue because they fail to provide the same benefit in terms of carbon sequestration and biodiversity than natural forests. The different shapes and sizes of trees composing native forests capture more efficiently sunlight.

Scientists explain that monoculture plantations are not useless, but should be in addition to the 1.35 million square miles of restored natural forests that the Bonn Challenge is aiming, not instead of them. Policies must acknowledge both the type of tree that needs to be planted and how the tree bonds with the larger health of the forest.

Poor land management

The 2016 Fort McMurray fire in Canada is another example of poor forest management. This fire has displaced more than 80,000 people and has been described as the costliest natural disaster in Canadian history. The wildfires have started in peat swamps, a wet forest where native trees scarves of water-dense, flame-retarding peat moss. How had a swamp burned with such severity? The answer lays in a miscalculated 1980 government campaign for forest growth. As part of an experiment of converting bogs to timber, the Canadian government drained large areas of the Alberta swamps and planted black spruce, spacing them for maximum growth. The trees gorged themselves on the groundwater out of the swamps.

 As a result, they grew an unusually wide canopy that chocked out the peat moss. A drier moss replaced it and as the land dried the trees grew into huge stores of fuel.

Furthermore, a study by Chinese ecologists reviewed the results of one of the 1952 China large-scale tree-planting campaign of afforestation. The program aiming the country’s arid regions to fight desertification has damaged local ecosystems. Foresters planted huge tracts of thirsty non-native trees, that had sucked up the groundwater as they grew, dropping the water table to dangerous levels. The afforestation program must be reassessed with future species selected for drought tolerance and ability to subsist on little water.


In order to meet global climate commitment, forest-restoration schemes must increase their carbon sequestration potential. According to Nature, there are four ways to attain it:

  • Countries should increase the proportion of land that needs to be regenerated to natural forests.
  • Prioritize natural regeneration in the humid tropics which all support very high biomass forest compared with drier regions.
  • Build on existing carbon stocks. Target degraded forests and partly wooded areas for natural regeneration; focus plantations and agroforestry systems on treeless regions.
  • Once natural forest is restored, protect it by expanding protected areas; giving title rights to Indigenous peoples who protect forested land; changing the legal definition of how land may be used so it cannot be converted to agriculture or encouraging commodities companies to commit to not clearing restored natural forests.

Solutions at every level

The full picture is not black and white. A wide variety of promising opportunities for forest restoration exist around the world and many countries, organisations and companies are already committed to restore and protect natural forests.

  • UN declared 2021-2030 as the UN Decade on Ecosystem Restoration. The goal is to reverse centuries of damage forests, wetlands and other ecosystems. The UN calls countries, the international community, civil society, businesses, and others for strong commitments in order to achieve ecosystem restoration. All ecosystems are concerned, including forests, grasslands, croplands, wetlands, savannahs, inland water, coastal and marine ecosystems, and even urban environments. The resolutions range from showcase successful government-led and private initiative to halt ecosystem degradation to connect initiatives working in the same landscape or topic to increase efficiency and impact.  
  • WWF has called for the planting and protection of 1 trillion trees worldwide by 2050. They connect funders with forest conservation ventures and inspire society to protect and restore forests.

Ethiopia has made progress during the last 20 years with the land restoration campaign launched by the government in 1991. Farmers stopped using damaged land for grazing to allow trees to regenerate naturally. More than one million hectares of lands and forests have been restored (2015) in the East and Central province of Tigray alone. A 2016 report by the UN Food and Agriculture organization found that community forestry is a powerful means of keeping resilient forests.

Nepal has seen a remarkable development of community forests. By helping communities to manage forests they depend on the national forest cover has risen of around 20% in the past three decades. This positive initiative has greatly impacted both communities’ livelihoods and the state of the forests.

Niger government agricultural advisors have advice farmers to nurture rather than remove trees on their lands. Farmers discovered that they got better grain yields if they let trees grow. As we have explained earlier, trees help stabilise the soil, retain nitrogen and dropped leaves that maintain soil moisture. In 20 years, farmers across the country have re-greened around 5 million hectares of degraded farmland. By doing that, they significantly improved their livelihood, just as the Nepal communities.


Ecosia: not-for-profit web browser that uses advertising revenue to plant trees around the globe, has reportedly planted 100,000,000 trees. Posts their financial reports each month.

 Ecologi: start-up platform that allows you to subscribe monthly and support climate friendly projects, notably tree planting/reforestation projects.

Eden Projects: International not-for-profit company that partners with other organisations whose ‘mission is to provide fair wage employment to impoverished villagers as agents of global forest restoration. We hire the poorest of the poor to grow, plant, and guard to maturity native species forest on a massive scale.’

Treeapp: phone app that asks its users to answer 2/3 questions per day that are sponsored by environmentally friendly companies, using this sponsorship to fund tree planting around the globe.

Trillion tree campaign: Campaign where people/countries can donate trees contributing towards the objective of planting one trillion trees.



Share This