The changes we are witnessing and those that are predicted are largely due to human behaviour. We are burning fossil fuels, and heating up the planet at the same time. We blow ever increasing amounts of carbon dioxide (CO2) into the atmosphere every year –
29 billion tonnes of it (2004) and rising – and this causes the temperature to increase.
Source: http://wwf.panda.org/about_our_earth/aboutcc/problems/rising_temperatures/
What causes the Earth’s climate to change?
Carbon dioxide is a greenhouse gas that absorbs energy from the Sun and then releases it back into the atmosphere. This process keeps the Earth warm.
Throughout most of the past 425,000 years the concentration of CO2 has ranged between 180 and 280 parts per million (ppm). When the concentration was at its highest the world was warmer.
Source: http://www.planetseed.com/relatedarticle/co2-and-temperature-change
Carbon cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.
These are the steps of the cycle:
1. Carbon enters the atmosphere as carbon dioxide from respiration and combustion.
2. Carbon dioxide is absorbed by producers to make carbohydrates in photosynthesis.
3. Animals feed on the plant passing the carbon compounds along the food chain. Most of the carbon they consume is exhaled as
carbon dioxideformed during respiration. The animals and plants eventually die.
4. The dead organisms are eaten by decomposers and the carbon in their bodies is returned to the atmosphere as carbon dioxide.
In some conditions decomposition is blocked. The plant and animal material may then be available as fossil fuel in the future for combustion.
5. as carbon dioxideformed during respiration. The animals and plants eventually die.
6. The dead organisms are eaten by decomposers and the carbon in their bodies is returned to the