Environmental change occurs when natural or man-made forces impact a particular area, habitat or the world as a whole. Many people regard environmental change as a negative development because such changes are often associated with pollution and the destruction of forests or nature preserves. Nevertheless, some types of environmental change can result in positive outcomes that improve people's lives.
During the 20th century, scientists became aware of global climate change which may have resulted in average temperatures rising in many parts of the world and more extreme weather conditions. Some scientists believe that global pollution has contributed to climate change while others argue that the temperature increases are cyclical. Regardless of the reason for the change, increased temperatures have lead to a variety of environmental changes around the globe. The polar ice caps have melted and this has negatively impacted creatures such as polar bears that use ice sheets as fishing platforms. Beyond the polar regions, rising seas levels have caused oceans to encroach on land in low lying areas and this has had an adverse impact on the people, animals and plants that exist in these environments.
Some types of environmental change are linked to human activities such as deforestation in South America, Asia and parts of Africa. Construction firms and logging companies fell large numbers of trees to sell as lumber but in doing so these firms alter the natural environment of many types of animals. Some species of animals face extinction due to the loss of habitat.
Environmental change can also occur as a result of certain types of species spreading into new areas and habitats. The introduction of a new species either by design or accident can disrupt the ecosystem because the new species has no natural predators in that environment. If the species devours certain types of crops or animals, then other species that previously relied on those food sources may struggle to survive due to the competition for food. This can have a domino effect because when one species starts to die out then the predators of that species also lose a food source and go into decline.
In some areas, governmental agencies and other organizations attempt to improve the environment by eliminating certain types of natural and man-made pollutants and toxins. Many types of species including animals tend to thrive in areas with clean water and fresh air. Therefore, efforts to eradicate pollution often result in a wide range of positive environmental changes that provide benefits for both humans and animals.