There is already overwhelming evidence that climate change and global warming affect both the distribution and behavior of animals and plants. Different species such as Edith’s checkerspot butterfly and the red fox have moved north or to higher altitudes. Breeding times for other species, including Mexican jays and tree swallows, have also changed, as have plants such as woodland phlox and butterfly grass. While these alterations indicate how animals are adapting to a changing climate, they may have an impact on competitiveness. Natural system changes will continue and escalate in the future, resulting in the degradation and loss of biodiversity.
• Effects on habitat diversity
Habitat disruption is a major effect of global warming on wildlife, in which ecosystems rapidly shift regarding climate change, limiting their ability to meet the demands of the species. Changes in temperature and water availability commonly alter habitats, affecting native plants as well as the animals that rely on them. If the temperature continues to rise one–fourth of all plants and animals on the planet can become extinct over the next 100 years. As every plant and animal has a purpose in the ecosystem, the extinction of one species can have far-reaching consequences for many others.
• Effects on life cycles
In addition to habitat disruption, climate change is causing delays in the timing of various natural seasonal occurences in wildlife. Seasonal variations in temperature, precipitation, and sunshine provide clues to many species about when to move, bloom, nest, or mate. Climate change disrupts these signals and forces wildlife to change life cycles and seasonal events. In the western United States, warming and drought stresses are drying out trees and making them more vulnerable to infestation by pine beetles and other insects. Wildfires are on the rise due to higher temperatures and increased fuel in the dead wood. To make matters worse, new research opposes the long-held notion that distinct species living in the same ecosystem react to global warming as a single unit. Instead, various species within the same environment are reacting differently, breaking ecological communities apart that have been centuries in the making.
• Effects on ocean biodiversity
The ecosystems in which fish, shellfish, and other marine species live can also be affected by changes in water temperature. As the ocean is warm year-round, some species may adapt by moving to cooler locations due to climate change. Warmer oceans cause more water to evaporate into the atmosphere. Increased vapor can produce more intense precipitation, such as heavier rainstorms, as it travels over land or converges into a storm system. Heavy rain in coastal locations can increase runoff and flooding, lowering water quality when pollutants from the land wash into bodies of water. Some coastal areas, such as the Gulf of Mexico and the Chesapeake Bay, have already been experiencing “dead zones,” which are areas where water is depleted of oxygen due to pollution from agricultural fertilizers carried by runoff. The lack of life in these waters gave rise to the term “dead zone.”