Climate Change: Factors
Geography: Cambridge International GCSE (2027 Exams), topic 5.1.2
Natural Causes of Climate Change
Natural climate change results from orbital shifts, sunspot activity, and volcanic eruptions affecting Earth's temperature and atmosphere.
Orbital changes
- Orbital changes affect natural climate change by altering Earth's position relative to the sun.
- Milankovitch cycles include three types: eccentricity, axial tilt, and precession.
- Milankovitch cycles influence the amount and distribution of solar energy received by Earth, changing global temperatures.
Types of orbital changes
- Eccentricity is the shape of Earth's orbit, changing over 100,000 years, from circular to elliptical.
- Axial tilt varies between 21.5° and 24.5° on a 41,000-year cycle, affecting season intensity.
- Precession is the wobble in Earth's rotation over 26,000 years, impacting the timing of seasons.
Sunspots
- Sunspots are dark areas on the sun's surface, with increased solar activity.
- More sunspots mean more solar radiation reaching Earth, causing slight warming.
- Periods with fewer sunspots, like the Maunder Minimum, have coincided with cooler climates.
Volcanic activity
- Volcanic eruptions release ash and gases into the atmosphere, influencing climate.
- Sulphur dioxide forms aerosols that reflect sunlight, causing temporary cooling.
- Large eruptions can reduce global temperatures for 1-3 years by blocking solar energy.
Test yourself on Climate Change: Factors
Over how many years does Earth's precession cycle occur?