Week 3: Our Changing Carbon Cycle

·         How human activity has contributed to an atmospheric concentration of carbon dioxide not seen since the Pliocene epoch between 2.6 and 5.3 million years ago.

·         The climate has been changing dramatically over the last 100-150 years.

·         This isn’t due to just natural variability in a system, it involves other components uh as emissions of greenhouse gases.

·         Carbon dioxide is one of the key gases that cause the warming blanket.

·         1 PgC = 10¹⁵ gC, 10PgC of carbon are released into the atmosphere ever year due to human activity.

·         90% of the emission of CO² comes from the burning of fossil fuels the remaining 10% comes from deforestation.

·         The main countries emitting CO² are USA, Europe and Japan, emerging countries like china and india are also contributing.

·         For deforestation the main emitters are European countries in the tropics such as brazil or Indonesia.

·         CO² emissions are above 10PgC per year.

·         The atmospheric increase in CO² is about 4.5 PgC per year.

·         The remainder of the CO² is absorbed by the land and the ocean.