Rainforest animals, like all life, are threatened by increases in atmospheric carbon dioxide that contribute to global warming. Excessive carbon dioxide in the atmosphere causes more of the sun's heat to get trapped rather than radiating out into space, raising the overall global temperature of the planet. This globalwide warming is often called "climate change."
Animals and the Carbon Cycle
Carbon dioxide is released into the atmosphere as a byproduct of animals' respiratory and digestive functions. Trees and other plants then absorb and store carbon dioxide. When they decompose, burn or get eaten by animals, the carbon dioxide they stored is released again into the atmosphere. This natural process is called the carbon cycle.
Because it contains so much vegetation, the rainforest is an important element in the carbon cycle. While most of the carbon dioxide that causes global warming comes not from the carbon cycle but from sources outside of the normal carbon cycle like burning fossil fuels, a healthy carbon cycle is critical to maintaining a healthy atmosphere.
Rainforest Animals and Plants
Because so much of the planet's vegetation is contained in the rainforests, their destruction decreases the amount of carbon dioxide the carbon cycle can handle. Rainforest animals, like the rainforest itself, suffer from a number of threats. For one, tens of thousands of acres of rainforest are destroyed every day for human developments and agriculture. The destruction of this plant life has a direct effect on rainforest animals, which depend on the plants for shelter and food.
It also has an indirect effect on animals. Rainforest plants absorb much of the carbon dioxide handled in the carbon process. When those plants are destroyed, that carbon is not regularly removed from the atmosphere. It then contributes to climate change, which can make the animals' habitats too hot for them to live in. This process is suspected as the cause of a decreased population of rainforest amphibians in Costa Rica since 1970. If the levels of carbon dioxide and other greenhouse gases continue to increase, many of these amphibian species are expected to become extinct.
Some scientists have shown that climate change brought on in part by increases in carbon dioxide in the atmosphere has reduced rainfalls over certain Brazilian rainforests. The reduction in rainfalls has actually caused greater vegetation growth in these areas, likely due to increases in sunlight. This is good news for animals as well, which will have increased food supply and more habitat in which to live. The benefits of reduced rainfall, though, are likely to be short lived as most climate models predict massive rainforest die-offs as the region becomes even drier.
Nutrients Make It Worse
The chemicals that scientists often refer to as plant nutrients--nitrogen and phosphorous--are regularly added in the form of fertilisers to crops to aid and quicken their growth. A certain amount of these chemicals finds its way into rainforest soil. Scientists have discovered that higher concentrations of nitrogen and phosphorous in rainforest soil can quicken the release of carbon dioxide from decaying plant matter. Again, the additional carbon dioxide speeds climate change which can lead to the demise of rainforest plants and the animals that depend on them.
Experts estimate that 35 animal species a day, on average, go extinct in the rainforest due to habitat destruction, pollution and poaching. As rainforests feel the effects of rising levels of carbon dioxide, the number of rainforest animal extinctions will only rise. Animal species that scientists have not yet been able to identify, much less observe and study, are among those rainforest creatures becoming extinct.