Humans affect the carbon cycle by exhaling carbon dioxide, burning fossil fuels, cutting down forests and poor farming practices. While breathing is necessary to survival, there are other ways to slow the cycle.
The natural amount of carbon dioxide exhaled by humans is used by plants and vegetation to produce necessary oxygen. When there is an excess of fossil fuels that are burned, a large concentration of carbon dioxide is released into the atmosphere. Deforestation reduces the number of trees, which in turn reduces the Earth's carbon dioxide levels. This results in soil that is less suitable for new growth.
Half of the carbon emitted by humans goes up into the atmosphere, which contributes to global warming. Carbon dioxide is a greenhouse gas that creates heat energy. The other half of the carbon is absorbed by vegetation, lakes and oceans, which is the carbon sink. The carbon is stored in the earth's soil, where it is later released into the atmosphere. In this way, a cycle evolves. Carbon dioxide can eventually be absorbed into the biosphere, and into rocks to form limestone.
Carbon dioxide can linger for hundreds of years, so the impact expands over generations. During various periods of time in history, the carbon cycle has risen. For example, when volcanoes erupt, they release lava and gases, including carbon dioxide. Volcanoes don't erupt often these days, so their impact has lessened. Burning wood, trees and fossil fuels increases the concentration of carbon dioxide.
Evidence indicates that the carbon dioxide concentration has risen steadily over time, with a few spikes like the aforementioned volcanic activity. There are now more people in the world, and much more automation and technological advances that contribute to the increase. Research is underway to determine if photobleaching or ultraviolet light can have a reverse effect on carbon cycling. Farm crops and agricultural methods are currently under study to see if they can find ways to reduce carbon emissions. This farming aspect is part of sustainable development that eventually effects food sources. But there are also ways that individuals can cut back on their carbon footprints. This is much like getting back to the basics.
Humans can reduce their carbon footprint in simple, uncomplicated ways through their daily routines. One way is to hang laundry out to dry instead of using an electric or gas dryer. Another is to turn down the heat in the house. Even lowering the thermostat's temperature a degree or two can make a difference. Take shorter showers, and only use as much water as you need. Turn off electrical appliances when they aren't being used. Plant trees. Carpool, walk or ride your bike when possible. Use energy-efficient appliances. Recycle and refurbish when possible. Use reusable BPA-free water bottles instead of plastic disposables to reduce waste in landfills, where heat can be emitted.
Encourage similar practices at work. The more people that get involved, the bigger impact on the carbon footprint for future generations. Many of these suggestions also save money and energy while ultimately reducing the amount of carbon dioxide released into the earth's environment.