Climate change can result from natural processes and factors.
Examples of natural factors include:
- Changes in the Suns intensity (strenght) e.g sunspots
- Slow changes in the earths orbit (path) around the sun
- Volcanic Eruptions
Changes in the Suns Intensity
- Scientists have identified changes in the amount of energy coming from the sun that is linked to sunspots.
- Sunspots are black areas that appear from time to time on the surface of the sun.
- Sunspots occur on an eleven-year cycle where they rise to a peak number and then fall to a minimum number. This is known as a sunspot cycle.
- More heat is given off during a sunspot maximum because of large explosions occuring on the surface of the sun. When sunspots are at a minimum, this lower energy from the sun can lead to lower temperatures on Earth.
Slow Changes in the Earths Orbit around the Sun
- The Earths orbit is sometimes circular but sometimes it can be more oval (elliptical)
- The Earths axis tilts. Soemtimes the Earth is more upright and soetimes it is on its side.
- The earths axis sometimes wobbles over a long period of time.
- These three changes have an impact on the amount of sunlight that the Earth receives on the timing of the seasons and on climate.
- Over periods of thousands of years these changes can cause climate change.
Volcanic Eruptions
- Volcanic Eruptions have an ifluence on climate in the short term.
- Erupting volcanoes often emit sulphur dioxide that combines with water to form sulphuric acid.
- The sulphuric acid make tiny droplets that reflect incoming radiation from teh sun, causing cooling on the earths surface.
Example
The eruption of Mount Pinayubo in the Philippines in 1991 released 17 million tonnes of sulphur dioxide. This had an impact on global sunlight, reucing it by 10% and cooling the planet by 0.5 celcius for a period of 1-3 years.