Human consumption, population growth and global trade have created a demand for natural resources that exceeds what the earth can replenish. Deforestation and forest degradation are key causes of this climate change imbalance.
People depend on forests for food, water, medicine and wood. When forests are lost or degraded, it sets off a chain of events that affects life both locally and around the world.
Soil Erosion
When land becomes eroded, the top layer of soil, which is high in organic material, loses its fertility. It is carried away by wind or water and deposited elsewhere. Erosion reduces cropland productivity and can even lead to the pollution of nearby waterways, lakes and wetlands. This erosion process is most accelerated by human activities, including overplowing and unsustainable agriculture methods.
Farming practices, especially tillage and the use of fertilizers, contribute to erosion. In addition, grazing animals also destroy the soil through their feeding habits. Erosion also increases with weather extremes, such as heavy rainfall and snowmelt. Moreover, bare lands are more vulnerable to erosion because they lack the protective cover of vegetation and the ability to retain moisture and nutrients.
The speed of soil erosion depends on the weather and soil characteristics, such as aggregation, infiltration, ground cover and slope. In general, more textured soils with high organic matter are less susceptible to erosion than sand and gravel-based types. In addition, knolls and shoulder slopes experience more erosion than flat areas because they have greater surface friction.
There are different types of soil erosion, mainly by water or wind. Sheet erosion, for instance, occurs evenly over a uniform slope and usually goes unnoticed until most of the productive topsoil has been eroded. It is usually accompanied by changes in soil color, reduced crop yield and deposition at the bottom of the slope. Other indicators of sheet erosion include lighter-colored soils on knolls and shoulders, change in the thickness of soil horizons and low crop yields.
When eroded soil is washed away by rain or runoff, it can pollute waterways. This dirty water contains harmful chemicals such as pesticides and fertilizers. It also clogs grassed waterways and dams, which can increase flooding and siltation.
In addition to this, the contaminated dirt that makes it to the waterways can also cause harmful algal blooms and poison drinking water. Moreover, the soil particles can be inhaled by humans and livestock, causing lung diseases. Eroded soil also loses its ability to hold moisture, which reduces the growth of plants and crops.
Water Pollution
Deforestation impacts water quality in a variety of ways. Without trees to hold the soil in place, erosion carries dirt and other debris into rivers and streams. When this material combines with organic materials such as leaves, woody debris and sewage, it is carried long distances into lakes and estuaries, resulting in water pollution. This water pollution can have a direct impact on climate change by altering the flow of greenhouse gasses, such as carbon dioxide, into the atmosphere.
Tropical forests are the source of most deforestation, as people clear them to use the land for logging, cattle ranching, oil palm and rubber tree plantations, and mining. The practice of slash and burn farming, which involves burning swaths of forest to prepare the land for planting, is an important factor as well. The fertile soil resulting from this process can quickly wash into rivers, however, and is then used for growing other crops that are unable to hold the land in place and contribute to further soil erosion.
The loss of forest vegetation also impacts biodiversity. Forests are home to an incredible array of animal and plant species, many of which are unique and exist only in small geographic areas. The loss of these forests can lead to their extinction.
Climate change is causing changes in rainfall patterns that will challenge farmers and natural ecosystems alike. The resulting changes in water supply will affect drinking water, crop production and property values, not just in the United States but around the world.
As the planet’s water resources become increasingly stressed, it is critical that we take action to mitigate climate change and conserve our Earth’s dwindling forests. The key to preventing the worst effects of global warming is to understand how all of these environmental issues are linked. As we learn more about the interactions between these disciplines, we will be able to develop solutions that will save lives and protect our environment.
Greenhouse Gas Emissions
Since 1750, the amount of greenhouse gases like carbon dioxide in the atmosphere has increased by 47 percent. When these gases are released, they create an insulating blanket around the Earth and trap more heat from the sun inside our atmosphere. This extra heat raises global temperatures, a phenomenon called climate change.
The most common source of human-caused, or anthropogenic, emissions is burning fossil fuels, including coal, oil, and natural gas to produce electricity and heat buildings. This accounts for about one-quarter of worldwide human-driven emissions. It’s also the largest single source of emissions in the United States, responsible for 28 percent of national emissions in 2021. These emissions also include small amounts of methane and nitrous oxide, along with the man-made fluorinated gases chlorofluorocarbons used in refrigeration and air conditioning.
Forest fires, agricultural activities, and land use changes are the other major sources of human-caused greenhouse gases. The vast majority of these come from deforestation, with methane and nitrous oxide as significant contributors. These are called long-lived greenhouse gases, because their impact on warming lasts a much longer time than other gases, such as CO2. Because of this, when scientists report greenhouse gas emissions, they usually refer to them in terms of CO2-equivalent (CO2e).
The transportation sector contributes to about another quarter of all U.S. greenhouse gas emissions, with gasoline and diesel fuel combustion producing the most emissions. These also include small amounts of methane and nitrogen oxide from vehicle air-conditioning and refrigerant systems.
Climate scientists and environmental advocates agree that the best ways to reduce greenhouse gas emissions are to stop deforestation, move to renewable energy, and improve efficiency in residential, commercial, and industrial buildings. This includes replacing older, less-efficient equipment with more efficient models, using advanced technologies, and shifting to lower-emission power plants.
Other important strategies for cutting greenhouse gas emissions include capturing carbon as it enters the atmosphere as a byproduct of fossil fuel burning and transporting it deep underground in carefully selected and suitable geologic formations, where it’s safely stored away. This method of carbon capture and storage is often called “geological sequestration.” EPA’s ENERGY STAR program helps Americans save money and reduce their greenhouse gas emissions by promoting the purchase of a wide range of energy-saving products, from appliances to home insulation to commercial roofing.
Species Loss
Species that live in forest habitats such as birds, mammals and insects need forest cover to survive. When forests are cut down, those species lose their homes. As a result, their numbers drop and some species are driven into danger or even out of existence.
Deforestation also drives climate change. Trees absorb carbon dioxide from the air through photosynthesis, locking it chemically in their wood. When they are logged and burned, the stored carbon is released into the atmosphere. This increases greenhouse gas levels and speeds up global warming.
The same is true for other types of natural ecosystems, including peatlands and ocean habitats like mangroves. Preserving and restoring these ecosystems helps reduce greenhouse gases, which in turn slows down global warming.
Earth’s climate is already changing dramatically because of human-caused emissions of heat-trapping greenhouse gases. The Earth’s temperature is rising, glaciers and ice sheets are melting, rivers and lakes are drying up, and plants and animals are shifting their geographic ranges to accommodate the changes.
Climate change is causing more and more severe weather events, from extreme heat to heavy rains and flooding. These conditions are disrupting people’s lives and causing economic losses and social problems. People and places least able to adapt are being hardest hit.
As the Earth warms, biodiversity is under threat in every region. Many species will disappear entirely from their native homes, and those that remain will struggle to adapt. As a result, ecosystem services that help sustain our quality of life are being lost, including water supply, food security and pollination.
Biodiversity destruction is a triple planetary crisis. The world must tackle these issues together if we are to advance the Sustainable Development Goals and keep our planet viable for future generations. That’s why Earthjustice is fighting to protect iconic wildlife, from wolves and orangutans to wild turkeys and manatees, from hunters and poachers who threaten their survival, as well as fighting to limit deforestation and other forms of natural space degradation.
