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The causes of climate change - Coggle Diagram
The causes of climate change
The cause of climate change
Natural causes of climate change
Variation in energy from sun.
Sunspots are darker patches on the Sun's surface. They are caused by magnetic activity inside the sun. Sunspots increase from a minimum number to a maximum number in a sunspot cycle of about every 11 years. Scientists suggest that the more sunspots there are, the more heat is given off by the sun. However, solar output from the Sun has barely changed in the last 50 years, so it cannot be responsible for the climate change see since the 1970s
Changes in the earths orbit.
The distribution of the Sun's energy on the Earth varies due to changes around the Sun are called Milankovitch cycles. There are three of them: axial tilt, precession and eccentricity
Precession
The earth is not a perfect sphere, as the Earth spins it wobbles on it's axis in a 26,000 year cycle.
Eccentricity
The Earth's orbit around the sun is not fixed and changes over time from being almost circular to being mildly elliptical. The cycle takes 100,000 years. Colder periods occur when the Earth's orbit is more circular and warmer periods when it is more elliptical
Axial Tilt
The earth spins in its tilted axis. The angle of the tilt changes due to gravitational pull of the Moon. When the angle of the tilt is greater, it is associated with a higher average temperature. The angle of the tilt moves back and forth every 41,000 yrs
Volcanic Activity
Volcanic eruptions throw huge quantities of ash, gases and liquids into the atmosphere. When sulphur dioxide mixes with water vapour it becomes a volcanic aerosol. Volcanic aerosols reflect sunlight away, which reduces global temperatures. Wind carries material far beyond where it was ejected from the volcano, so the reduced temperatures also experienced elsewhere.
How human activity contributes to global warming?
What is greenhouse effect?
The natural greenhouse effect is a naturally occurring phenomenon that keeps the Earth warm enough for life to exist. Without it, the Earth would be about 33 degrees codler. This is the process
The Sun's infrared heat rays enter the Earths atmosphere.
The heat is reflected from the Earth's surface.
The natural layer of greenhouse gases allow some heat to be reflected out to of the Earth's atmosphere but some is trapped. This keeps the Earth warm enough.
The enhanced greenhouse effect
Scientists have provided that natural causes are responsible for climate change, yet they cannot account for the increases in temperature since the 1970s. Humans must also be contributing to the greenhouse effect.