Impacts of climate change
Climate change is causing global temperatures to increase and average sea levels to rise.
Causes of climate change
Temperature variations are caused by a combination of physical and human factors.
Physical causes
Physical causes of global warming and cooling include:
Variations in solar energy
- sunspotA dark area on the surface of the Sun, showing lower surface temperature. result in the Sun emitting less energy. This reduces the global temperature.
- solar flareA short burst of increased energy from the Sun. raise global temperatures.
The Little Ice Age of 1650鈥1850 may have been caused by a decrease in solar activity
Milankovitch cycles
- The Earth's orbit round the Sun varies in shape. Global temperature increases and decreases depending on close the planet is to the Sun.
- The tilt of the Earth changes. More tilt means warmer summers and colder winters, less tilt has the opposite effect.
- The Earth wobbles on its axis. This can change the timing of seasons and affect how big the range in temperature between high and low is.
Volcanic eruptions
- Large quantities of volcanic dustSmall particles released from a volcano. in the atmosphere shield the Earth from incoming insolationSolar radiation received in the Earth's atmosphere and on its surface., lowering the global temperature.
- Volcanic eruptions can cause warmer winters
Changing oceanic circulation
Changing oceanic circulationThe continuous movement of water in the oceans. can affect climate patterns and temperatures around the globe.
- El Ni帽oAn increase in the surface temperature of the sea, particularly in the tropical eastern Pacific. This occurs every few years and can affect climate patterns around the globe. brings warmer, wetter weather to the eastern Pacific and can result in colder winters in the UK
- La Ni帽aA decrease in the surface temperature of the sea, particularly in the tropical eastern Pacific. This occurs every few years and can affect climate patterns around the globe. brings cooler, drier weather to the eastern Pacific and can lead to more tropical storms developing in the North Atlantic.
Melting permafrost
Melting permafrostPermanently frozen soil. releases large quantities of methaneA colourless gas that can do harm to life forms. gas. This adds to the natural greenhouse effect, increasing global temperatures.
All these physical causes of global temperature change have always existed and have been responsible for the alternating heating and cooling cycles of the Earth's temperature.