Deforestation is one of the main contributors to climate change. It comes in many forms: wildfire, agricultural clearcutting, livestock ranching, and logging for timber, among others. Forests cover 31% of the land area on Earth and annually 75,700 square kilometers (18.7 million acres) of forest is lost. Mass deforestation continues to threaten tropical forests, their biodiversity and the ecosystem services they provide. The main area of concern of deforestation is in tropical rainforests, since it is home to the majority of the biodiversity. Organisations such as World Wildlife Fund focus on the preservation of nature and the reduction of the most pressing threats to the diversity of life on Earth.
Deforestation is the second largest anthropogenic source of carbon dioxide to the atmosphere, after fossil fuel combustion. Deforestation and forest degradation contribute to atmospheric greenhouse gas emissions through combustion of forest biomass and decomposition of remaining plant material and soil carbon. It used to account for more than 20% of carbon dioxide emissions, but is currently around the 10% mark. By 2008, deforestation was 12% of total CO
2, or 15% if peatlands are included. These proportions are likely to have fallen since given the continued rise of fossil fuel use.
Averaged over all land and ocean surfaces, temperatures warmed roughly 1.53 °F (0.85 °C) between 1880 and 2012, according to the Intergovernmental Panel on Climate Change. In the Northern Hemisphere, 1983 to 2012 were the warmest 30-year period of the last 1400 years.
A large contributing factor to deforestation is the lumber industry. The reason behind this is due to logging since it is so common due to frequent wood production uses in many people's daily lives. A total of almost 4 million hectares (9.9×106 acres)  of timber is harvested each year. In addition, the increasing demand for low costing timber products only supports to the lumber company to continue logging. The carbon emitted from the process of converting timber to wood products accounts for 15% of the carbon emissions in the environment. Deforestation is a main concern in tropical rainforest since it is home to millions of animals in the biodiversity. Not only does the lumber industry impact deforestation but also the environment due to deforestation drives on climate change.
Urbanisation is the process of clearing a large area of land to build more living space. As a result of expanding land for residential and urban purposes, there is a significant amount of forest loss. As the human population continue to increase throughout the years, the demand and needs for necessities also increase. This means that more land is needed to be cleared in order to build more homes, recreational uses, and agriculture. In addition, this also promotes the industrialisation to grow and require more land to provide consumers with the food products demanded.
Livestock ranching requires large portions of land to raise herds of animals and livestock crops for consumerism needs. Livestock ranching originated in Texas between 1820 and 1865 which were mainly driven by Mexican cowboys. Later, Texans drove the Mexicans out, while leaving the cattle behind. After the civil war, Texans begin rounding up the cattle and selling them around states such as California and New Orleans. According to Greenpeace, a non-governmental global environmental organisation, the cattle industry is responsible for a significant amount of methane emission. This is because speculators burn huge areas of rainforest for pasture. Rhett Butler says over 60% of land that is deforested become pasture for animals such as cattle and cows.
The number one largest cause of deforestation and acute degradation is agriculture. According to Wageningen University and Research Centre, more than 80% cause of deforestation is agriculture. A continued increase of demand for timber and agricultural products are only critical indirect drives. Forest are giving way to plantation for coffee, tea, palm oil, rice, rubber, and many other highly demanded products. These rising demands for certain products and global trade arrangements causes forest conversions, which ultimately leads to soil erosion. The top soil oftentimes erodes after forests are being cleared which leads to sedimentation increase in rivers and streams. Over time, agricultural land degrades and becomes almost useless causing producers to find new productive lands.
A 2007 study conducted by the National Science Foundation found that biodiversity and genetic diversity are codependent—that diversity among species requires diversity within a species, and vice versa. "If any one type is removed from the system, the cycle can break down, and the community becomes dominated by a single species."
Forests are nature's atmospheric carbon sink; plants take in atmospheric carbon dioxide (a greenhouse gas) and convert the carbon into sugars and plant materials through the process of photosynthesis. The carbon is stored within the trees, vegetation, and soil of the forests. Studies show that “intact forests,” in fact, do sequester carbon. Examples of large forests that have a significant impact on the balance of carbon include the Amazonian and the Central African rainforests. However, deforestation disrupts the processes of carbon sequestration and affects localised climates. Additionally, cutting down trees plays a role in a positive feedback loop centred around climate change on a much larger scale, as studies are finding.
Burning or cutting down trees reverses the effects of carbon sequestration and releases greenhouse gases (including carbon dioxide) into the atmosphere. Furthermore, deforestation changes the landscape and reflectivity of earth's surface, i.e. decreasing albedo. This results in an increase in the absorption of light energy from the sun in the form of heat, enhancing global warming.
Trees are a major source of carbon. It is estimated that the amount of carbon within the Amazon exceeds the ten year's worth of carbon released by human production. Unfortunately, since forests are often cleared by fire such as in slash and burn agriculture, the combustion process of wood release huge amounts of carbon dioxide into the atmosphere. The increase of atmospheric carbon is not the only consequence of deforestation, changes in soil properties could turn the soil itself into a carbon contributor. According to scientists at Yale University, clearing forests changes the environment of the microbial communities within the soil, and causes a loss of biodiversity in regards to the microbes since biodiversity is actually highly dependent on soil texture. Although the effect of deforestation has much more profound consequences on sandier soils compared to clay-like soils, the disruptions caused by deforestation ultimately reduces properties of soil such as hydraulic conductivity and water storage, thus reducing the efficiency of water and heat absorption. In a simulation of the deforestation process in the Amazon, researchers found that surface and soil temperatures increased by 1 to 3 degrees Celsius demonstrating the loss of the soil's ability to absorb radiation and moisture. Furthermore, soils that are rich in organic decay matter are more susceptible to fire, especially during long droughts. As a consequence of reduced evapotranspiration, precipitation is also reduced. This implies having a hotter and drier climate, and a longer dry season. This change in climate has drastic ecological and global impacts including increases in severity and frequency of fires, and disruption in the pollination process that will likely spread beyond the area of deforestation.
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation. It is the reestablishment of forest cover either naturally or artificially. Similar to the other methods of forestation, reforestation can be very effective because a single tree can absorb as much as 22 kilograms (48 lb) of carbon dioxide per year and can sequester 0.91 tonnes (1 short ton) of carbon dioxide by the time it reaches 40 years old.
Afforestation is the planting of trees where there was no previous tree coverage. Degradation of forest ultimately leads to a decrease in oxygen and a sufficient increase of carbon dioxide. In order to make up for the loss, more trees are being planted. As a result, the amount of carbon dioxide in the atmosphere could significantly decrease. According to a scientific research, plantation forest could absorb more carbon dioxide than natural forest since they grow faster leading to a higher absorbance rate. The process is usually encouraged by governments because they want it to lead to a decrease in carbon dioxide and because it increases the aesthetics of the area. Although, it could lead to infringing upon ecosystems and create complications in environments that previously did not have tree coverage or forests.
Although China has set official goals for reforestation, these goals were set for an 80-year time horizon and were not significantly met by 2008. China is trying to correct these problems with projects such as the Green Wall of China, which aims to replant forests and halt the expansion of the Gobi Desert. A law promulgated in 1981 requires that every school student over the age of 11 plant at least one tree per year. But average success rates, especially in state-sponsored plantings, remains relatively low. And even the properly planted trees have had great difficulty surviving the combined impacts of prolonged droughts, pest infestation and fires. Nonetheless, China currently has the highest afforestation rate of any country or region in the world, with 4.77 million hectares (47,000 square kilometres) of afforestation in 2008.
The primary goal of afforestation projects in Japan is to develop the forest structure of the nation and to maintain the biodiversity found in the Japanese wilderness. The Japanese temperate rainforest is scattered throughout the Japanese archipelago and is home to many endemic species that are not naturally found anywhere else. As development of the country's caused a decline in forest cover, a reduction in biodiversity was seen in those areas.
Agroforestry or agro-sylviculture is a land use management system in which combinations of trees or shrubs are grown around or among crops or pastureland. It combines agricultural and forestry technologies to create more diverse, productive, profitable, healthy, and sustainable land-use systems. There are many benefits to agroforestry such as increasing farm profitability. In addition, agroforestry helps to preserve and protect natural resources such as controlling soil erosions, creating habitat for the wildlife, and managing animal waste.
Recognition of the negative impacts of deforestation and of the overwhelming evidence of global warming has led to the development of international policy surrounding the conservation of forests. One attempt towards fighting climate change globally is the Reducing Emissions for Deforestation and Forest Degradation (REDD+) efforts, and a few countries are already starting to implement and analyse ways to protect standing trees.
In the case of the Bac Kan province in Vietnam, researchers came up with systems to encourage leaving forests intact while also meeting international, national, and individual investments successfully. Their methods included “benefit-distribution systems” and dividends for ecosystem services. The researchers hope that their results “can be replicated and directly contribute to reducing carbon emissions globally.”
Founded in 1972, the centennial of the first Arbor Day observance in the 19th century, the Foundation has grown to become the largest nonprofit membership organisation dedicated to planting trees, with over one million members, supporters, and valued partners. They work on projects focused on planting trees around campuses, low-income communities, and communities that have been affected by natural disasters among other places.
The Billion Tree Campaign was launched in 2006 by the United Nations Environment Programme (UNEP) as a response to the challenges of global warming, as well as to a wider array of sustainability challenges, from water supply to biodiversity loss. Its initial target was the planting of one billion trees in 2007. Only one year later in 2008, the campaign's objective was raised to 7 billion trees—a target to be met by the climate change conference that was held in Copenhagen, Denmark in December 2009. Three months before the conference, the 7 billion planted trees mark had been surpassed. In December 2011, after more than 12 billion trees had been planted, UNEP formally handed management of the program over to the not-for-profit Plant-for-the-Planet initiative, based in Munich, Germany.
Considered the largest reserve of biological diversity in the world, the Amazon Basin is also the largest Brazilian biome, taking up almost half the nation's territory. The Amazon Basin corresponds to two fifths of South America's territory. Its area of approximately seven million square kilometres covers the largest hydrographic network on the planet, through which runs about one fifth of the fresh water on the world's surface. Deforestation in the Amazon rainforest is a major cause to climate change due to the decreasing number of trees available to capture increasing carbon dioxide levels in the atmosphere.
The Amazon Fund is aimed at raising donations for non-reimbursable investments in efforts to prevent, monitor and combat deforestation, as well as to promote the preservation and sustainable use of forests in the Amazon Biome, under the terms of Decree N.º 6,527, dated August 1, 2008. The Amazon Fund supports the following areas: management of public forests and protected areas, environmental control, monitoring and inspection, sustainable forest management, economic activities created with sustainable use of forests, ecological and economic zoning, territorial arrangement and agricultural regulation, preservation and sustainable use of biodiversity, and recovery of deforested areas. Besides those, the Amazon Fund may use up to 20% of its donations to support the development of systems to monitor and control deforestation in other Brazilian biomes and in biomes of other tropical countries.