The Deforestation Feedback Loop

 

Trees and other plants help clean the atmosphere. They ‘breathe’ in carbon dioxide and ‘breathe out’ oxygen. As parts of our world become hotter and drier, trees and plants get less of the water they need to survive. Our forests are shrinking and even dying, this is mainly happening to our rain forests. A hotter planet also means more trees burning in forest fires. The loss of forests on a large scale is called deforestation. Fewer trees on the planet means less carbon dioxide absorbed from the atmosphere and rotting and dying trees that are unable to clean the air. This results in a lot more carbon dioxide in the atmosphere means a warmer Earth. More warming means more deforestation.

The Permafrost Feedback Loop

Cold parts of the Earth such as the Arctic aren’t always covered in ice and snow, but they are cold enough to have ice all year round. This is called the Permafrost. Permafrost holds all of the unusual things that soil contains, including the remains of dead animals. Part of these animals are huge, like the frozen mammoths which were found in Russia. These ancient creatures have been preserved in the permafrost for over four thousand years. Because the Earth is warming, the permafrost is starting to melt. The animals preserved in the permafrost also thaw up as this happens. Their remains are broken down by sunlight and bacteria, a process that produces carbon dioxide and methane. This increase in greenhouse gasses which warms the Earth even further, causing more permafrost to thaw. More thawing permafrost leads to more thawing remains and more carbon dioxide and methane being released.

The Ice Albedo Feedback Loop

 

The coldest parts of our planet are covered in ice all year. Because ice is a light colour, it reflects the sun’s heat energy back into space, which helps keep the Earth cooler. But when the temperature rises, the ice starts to melt, exposing water or land underneath. The surfaces colour is darker than ice, causing it to absorb heat instead of reflecting it, making the Earth hotter rather than cooler. The amount of light a surface reflects is called its albedo. As Earth’s temperature continues to rise, more ice melts. With less ice to reflect the sun’s heat, while surfaces and sea absorb it, Earth’s temperature continues to warm it even further. Scientists say by 2040, the North Pole could be completely ice-free each summer. This feedback loop operates more slowly at the South Pole because there is more ice over Antarctica.

The Water Vapour Feedback Loop

When the temperature is at a specific level of heat energy, water evaporates and becomes water vapour. While the temperature increases its warmth, the faster the process can happen. On hot days, you’ll often notice that the laundry dries quicker or the days are stickier in the summer. This occurs because warm air can hold lots of moisture. Water Vapour is one of Earth’s most powerful greenhouse gasses. Note that most of the water vapour originate from the ocean, and because of climate change, the days get warmer and warmer. As the temperature rises, more water evaporates, and because warm air can hold more moisture than cold air, more water vapour stays in the atmosphere. By doing this, it absorbs more of Earth’s heat, causing further warming. While the days get even warmer, the course continues to repeat.