4.2 Climate change as a natural phenomenon

Question 1

Is Solar Energy Output responsible for climate change

Answer 1

• measured by observing sunspots on suns surface
• sunspots caused by magnetic activity inside sun, resulting in dark patches
• Satellites and radiometers to record intensity of solar energy output
• solar output barely changed, decreased. not respnsible

Question 2

Does orbital change cause climate change

Answer 2

• Earth’s orbit is ellipse. Suns is not perfectly in center - ellipse changes shape. Distance between sun and earth changes as earth orbits, climate becomes warmer
• Earths axis is titled on angle, changes due to gravitational pull, when tilt angle increases, summers get warmer, winters colder
• Earth is not perfect shape, as earth spins, wobbles on its axis in 26,000 year cycle
• These three orbital changes vary distrubution of Sun’s energy, significant impact on climate

Question 3

Is volcanic activity responsible for climate change?

Answer 3

• Yes
• June 1991, Mount Pinatubo in Philippines erupted.
• Ash cloud, thrown 40kilometers into stratosphere, carried around world in 3 weeks
• 20 million tonnes of sulphur dioxide released, mixed with water vapour to make volcanic aerosol
• This reflects sunlight away and reduce the Sun’s heat energy entering the Earth’s atmosphere
• Carbon dioxide also erupted, trapping the Sun’s heat in the Earth’s atmosphere, dropping the temperature