Physical causes of climate change
Physical causes of global warming and cooling include:
- Volcanic eruptions - large amounts of volcanic dust in the atmosphere shield the Earth from the sun, lowering the global temperature. For example, the eruption of Mount Pinatubo in 1991 caused a dip in global temperatures
- Milankovich鈥檚 Theory refers to differences in the tilt of the Earth in relation to the Sun. Every 41,000 years, there is a change in the tilt of the Earth鈥檚 axis. A greater tilt means more sunlight in Polar Regions
- Over a 97,000-year cycle, the Earth鈥檚 orbit stretches, affecting the amount of energy received
- Differences in solar energyThe energy received from the sun. - sunspot activity can increase or decrease global temperatures depending on which part of the sun is concentrating on Earth
- Retreating ice caps release additional fresh water leading to changes in oceanic circulation
- There has been a reduction in the albedo effect as reflection has decreased, because less snow and ice cover means more land is exposed
- Melting permafrost releases large quantities of methane gas from decomposing organic matter. Methane is more than 20 times more effective at trapping heat than CO2. Methane accounts for 20% of the enhanced greenhouse effect
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.