With the human population on Earth being overly populated, it could be a driving force behind global warming. Fossil fuels are increasingly used to facilitate mechanized lifestyles. With more demand for coal, oil, gas, and fuels being drilled/mined and then combusted, it releases CO2 into the atmosphere. This is detrimental since it traps the warm air, like a greenhouse, and temperatures gradually rise. As a consequence, global warming can cause a number of environmental issues, such as rising sea levels. With the gradually higher temperatures, this has led to more summer melting of glaciers and less snowfall (from later winters and earlier springs), which results in an imbalance in a great net gain in the ratio of runoff to ocean evaporation, and causes sea levels to rise. The exponential population growth rate plus the increased per capita usage of water and energy, especially with some individuals actually consuming too much food and space, is not sustainable.
Water use and energy correspond with each other; when water tables are decreasing, more energy is needed to lift the water out of the ground. As the population goes up, so does demand for the natural resources. If the demands rise too quickly, the resources could become scarce and result in raising cost.
Since nonrenewable resources can’t be replaced, price will increase when the supply diminishes. If a renewable resource was used, there will still be an increase in fees if longer distance shipping is required to reach areas where natural resources have decreased. Deforestation can also be a result of human activity, such as agricultural expansion, logging, development, and cutting trees for firewood. These activities rise along with the increase in population.
As the population increases, so does the demand for food; in order to meet that demand, more crops need to be produced, which requires land, and to get more land for cultivating, trees and forest need to be cut down. Deforestation can also contribute to destroying habitats and harm animals. They become easier targets for poachers and are unable to hide or camouflage, which could have a harmful effect and make them vulnerable to extinction. Unsustainable agricultural practices could lead to several issues, such as the use of toxic pesticides. They don’t just kill target pests but also beneficial insects, such as bees and ladybugs, other animals that eat poisoned insects, and soil microorganisms.
When there isn’t the appropriate irrigation technology and water management, these pesticides can runoff from fields to nearby rivers and lakes, then contaminate groundwater sources, and end up in marine environments. This pesticide pollution of water directly poisons freshwater ecosystems. When fertilizers are found in freshwater and marine areas, it alters the nutrient system and can result in eutrophication- a huge growth of algae due to excessive amounts of nutrient. This leads to low levels of oxygen dissolved in water, severe algal growth that blocks light necessary for plants, like seagrasses, to grow. When algae and seagrass die and decay, the oxygen in water is used up and this will result in low levels of dissolved oxygen, which can kill fish, oysters, crabs, and other aquatic animals.
Methane that is in rice paddies is produced by microscopic organisms that respire CO2, and the more CO2 that’s in the atmosphere, the rice plants will grow faster. Rice agriculture is becoming less climate friendly as the atmosphere is changing. Rice paddies are a very large source of methane, while rice is also the world’s second-most produced staple crop, especially as global demands for it increases as well as the world population. Without additional measures, the total methane emissions from rice agriculture will increase. Human settlement can have a negative effect on the environment. As populations increase, it will lead to loss of arable land, which is very needed for growing crops and raising livestock. This is because soil will eventually be over-farmed and lose nutrients, then dry up and will no longer be arable. With the soil degradation leading to desertification, it means that individuals will eventually have to migrate to find more land for farming, and the cycle may start over.
When humans migrate to cities, it could harm animals by producing light pollution, which is the brightening of the sky at night with artificial light. This has the potential of changing behaviors of animals like insects, mammals, birds, sea turtles, and fish, and also causes disorientation. An example would be when sea turtle hatchlings crawl towards artificial light sources in the city, causing them to become disoriented and be in dangerous positions (run over by cars or falling down sewers). When humans settle in urban environments, the landscape does not allow of absorption and filtering of rainwater.
This could contribute to water pollution, along with runoff from streets that carry heavy metals, oil, and contaminants from cars, all due to modern urbanization. Impervious surface areas, which are artificial structures (example: pavement) that are impenetrable materials, can increase from infrastructures like buildings, roads, parking lots, and sidewalks; this can increase stormwater runoff, when rainwater infiltration and natural groundwater recharge are eliminated, that causes soil erosion and contributes to sediment and nutrient pollution in rivers. It also collects solar heat, which when released, can raise air temperature and produce urban “heat islands”, and increase energy consumption in buildings.