Completed notes of the course

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LECTURE 1 – THE BASICS OF CLIMATE SCIENCE GREENHOUSE EFFECT Earth receives solar radiation (300 Watt per m2) but has greenhouse gases which makes it liveable. Some of these radiations are reflected, by the Earth's surface and by atmosphere, some is absorbed and then radiated back as infrared radiation. Heat is trapped by greenhouse gasses. - natural greenhouse effect: it makes sure that the earth has nice temperature (14 °C instead of -18°C). - enhanced greenhouse effect : ant hropogenic. Human caused emissions of greenhouse gases , tipping natural system out of the equilibrium of the past million years. how do we know the levels of CO2 of the past million years? Proxy data. Past Climates can be reconstructed using: - tree rings (because CO2 makes plants grow more) - ice cores (digging in ice, the deeper you go, the older you get) - fossils, pollen, ocean sediments, corals. EMISSIONS We are emitting a 35 G ton of CO2 every year. about 4/5 ton of CO2 per person every year. About half of the CO2 is captured back by ocean => less damage for the atmosphere, but it’s bad for oceans because it change s its pH and damages flora and fauna. Despite periodic historical values that peaked at 300, we are now at CO2 concentration levels that far exceed that value. And we notice an instantaneous peak in temperature, unusual compared to the speed of normal climatic cycles, with the famous Hockey stick graph of temperature and its explosive concentration around 1900. GLOBAL WARMING POWER (GWP) There are many gases: CO2, black carbon, Sulphur dioxide, NH3, NOX. Global warming cause d by CO2 remains there for centuries and decreases very slowly . And since temperature is the integral of emissions, to make the temperatures stop growing we MUST GET CO2 TO ZERO. The key is ZERO NET.…