earth and atmosphere Flashcards
What are the 3 main stages of the evolution of the atmosphere
Volcanoes gave out steam and carbon dioxide
Green plants evolved and produced oxygen
Ozone layer allows evolution of complex animals
Explain stage 1
Volcanos erupted releasing carbon dioxide, steam, methane and ammonia. The early atmosphere was mostly CO2 and water vapour with very little oxygen. The water vapour later condensed into oceans.
Explain stage 2
CO2 dissolved into the oceans. Nitrogen was in atmosphere because ammonia and oxygen reacted and was released by denitrifying bacteria. Nitrogen isn’t very reactive so increased as it wasn’t being broken down. Green plants photosynthesised removing CO2 and replacing it with oxygen. Oxygen increased. Carbon dioxide decreased
Explain stage 3
The amount of oxygen killed off organisms that couldn’t tolerate it. More evolved organisms were evolved who made use of the amount of oxygen. Oxygen created the ozone layer which blocked harmful rays from the sun and enabled more complex organisms to evolve. There is hardly any CO2 left
How does human activity effect the atmosphere
The population is increasing so we are giving out more CO2 when we respire. More energy is needed for heating and cooking. Country’s are becoming industrialised which means fossil fuels are having to be burned more releasing pollutants. More space os needed for houses and food meaning there is more CO2 cuz we chop down trees which take CO2 in. Also when volcanoes erupt more CO2 is released
How do green house gases keep the earth warm
The sun gives out electromagnetic radiation
Some of the waves pass through the atmosphere
The electromagnetic radiation with short wave lengths is absorbed by earth warming it up
What are the green house gases
CO2, Warner vapour and methane
What can green house gases do
Absorb and reflect heat radiation
What’s enhanced green house effect and when does it occur
It occurs when there are to many green house gases and it is when more heat is absorbed and less is re emitted back into space. This causes the earth to heat up
How have green house gases caused climate change
The amount of methane has risen due to the increase in live stock. Methane is a very effective green house gas which has caused the average temperature of earth to rise
What can climate change do
Causes severe flooding, due to polar ice caps melting
Why is historical data less accurate
Less data was taken over fewer locations
How can you estimate past data
Analyse fossils, tree rings or gas bubbles caught in ice sheets. These methods are much less accurate than modern measurements using instrumental sampling. Also they are much less representive of global levels
How can we slow down climate change
Cut down the amount of greenhouse gases in our atmosphere
How do we reduce carbon dioxide emissions
Walking/ y long instead of driving or turning your central heating down