Controls of Climate on Geological Timescales

This video begins at an quarry in southern Sweden. Here, Alasdair Skelton hacks out pieces of coal from a coal seam. He explains, that coal, oil and gas (fossil fuels) come from plants that lived at the same time (or earlier than) as the dinosaurs. This makes burning fossil fuels and therefore the climate crisis a geological problem.

This underpins the importance of understanding how Earth’s climate is controlled on geological timescales. This is by 3 factors:

• Heat from the Sun which makes the Earth warmer.

• The albedo effect which makes the Earth cooler.

• The greenhouse effect which makes the Earth warmer.

Heat from the Sun on its own would give the Earth an average temperature of 6 degrees. The albedo effect (a measure of how much heat is reflected back into space) would lower Earth’s average temperature to -18 degrees. The greenhouse effect (a measure of how much heat is trapped by the atmosphere) raises Earth’s average temperature to 14 degrees.

Today, Earth’s temperature on average is more than 15 degrees. The extra one degree is human-induced global warming.