Our climate is driven by a continuous flow of energy from the sun. Heat energy from the sun passes through the earth’s atmosphere, and warms the earth’s surface. The earth's atmosphere protects us from the radiation and the vacuum of the universe. Whenever the earth's temperature increases, the earth sends heat energy back into the atmosphere. Some of this heat is absorbed by gases in our atmosphere, like carbon dioxide (CO2) and ozone. These gases act as a blanket, trapping the heat and preventing it from being reflected too far away from our earthsurface. These gases maintain the average global temperature at around 15°C, which is warm enough to sustain life for humans, plants and animals. Without these gases, the average global temperature would decrease to around minus -18°C,  far too cold for higher lifeforms to exist. This natural warming effect is often refered to as a greenhouse effect. Our global climate has changed as well because of exclusive human behaviour like burning fossil fuels, resulting in an excess of CO2 output into our atmosphere.

The warming of the earth can result in unpredictable climate changes. Melting glaciers can cause certain rivers to overflow, while excessive water evaporation may cause the entire emptying of  rivers in other parts of the globe. Diseases are spreading and while some crops grow faster, others see yields slashed by diseases and drought. Strong hurricanes are becoming more frequent and increasingly destructive in force. The arctic sea ice is melting faster every year and  sea levels are rising. Freshwater resources are shrinking and increasing competition for water resources may cause armed conflicts in many regions worldwide. These climate changes also cause disruption of natural ecosystems, threatening biodiversity. Many animal and plant species are threatened by climate change, because they can’t evolve or even migrate fast enough to keep up in order to survive.

Stop Global Warming
European Commission - Climate change
United Nation Environment Programme - Climate change
Global Warming - Early Warning Signs
Global Warming International Center

Carbon dioxide (CO2) is generally seen as the main cause of rising global temperatures. Natural causes of CO2 in the earth's atmosphere include: Volcanic eruptions, wildfires, plant decay and even animal breathing. Photosynthesis in plants and its dissolving in water removes the CO2 out of our atmosphere again. However, the recent increase of CO2 in the atmosphere is mainly caused by human activities. We are increasingly burning fossil fuels like coal, oil and natural gas. Deforestation as well releases vast amounts of CO2 stored in trees and soil. As a result of these forms of CO2 release, our planet's greenhouse blanket (which protects us from the cold universe) thickens and is trapping increasing amounts of CO2 in the earth atmosphere, causing global temperatures to rise.

Greenhouse gas emissions can be greatly reduced in many ways. Most solutions involve increasing the efficiency of our energy use in order to reduce fossil fuel demand, while maintaining or even improving our current lifestyles. Many of the potential solutions have benefits beyond greenhouse gas reduction, like increased employment, stimulation of the high-tech manufacturing, and reduced urban air pollution. A combination of public interest and government sponsored programs can make these solutions a reality, although scientists increasingly agree that a change of attitude amongst consumers will be of great help to ever achieve global CO2 reductions in time. For example: industry can reduce emissions in flexible, cost-effective ways, which lowers the waste and enhance long-term profits. A reduction in automobile use, improved fuel efficiency standards, the use of solar or wind energy, and better public transport would reduce greenhouse gas emissions and reduce urban air pollution at the same time. Many businesses and individuals worldwide are also looking into sustainable and climate-neutral production and operation methods.