The Earth's Sea and Atmosphere

An envelope of different gases (air) surrounding Earth

It has an atmosphere that can support life

Nitrogen: 78% Oxygen: 21% 1% other gases:- Argon: 0.93% Carbon dioxide: 0.035% Varying amounts of water vapour Trace amounts of other gases

At first there was no atmosphere Then the surface cooled and formed a solid crust Volcanoes formed and released Carbon Dioxide, Methane, Steam and Ammonia The Earth cooled even more and the steam condensed to form the oceans Trees and animals evolved

Little or no oxygen A large amount of carbon dioxide Water vapour and a small amount of other gases

By oxidising copper. Move 100cm^3 of air over copper while heating it. Only the oxygen will react with the copper, so the amount of air left will have no oxygen. Therefore 100 minus the amount of air left will give you the oxygen content of air.

They were the first organisms to photosynthesise, which created oxygen, allowing other organisms to develop

O3

In the stratosphere

It blocks harmful radiation from the sun which can damage and kill life on Earth

It reacted with oxygen in the atmosphere to form nitrogen and water: 4NH3 + 3O2 —-> 2N2 + 6H2O

Iron bands were made of iron oxide or rust. The iron came from volcanic activity in the oceans and the oxygen came from stromatolites photosynthesising. They prevented the oxygen level from rising for a few billion years because they were using up the oxygen being produced. They eventually went away because there was so much life producing oxygen the iron was deposited where it formed.

It is 13 degrees Centigrade, compared to -22 degrees Centigrade without the greenhouse effect.

Stage 1: Radiation from the Sun in the form of light waves enters the atmosphere and warms the Earth Stage 2: Infrared radiation is produced by the Earth. Some of this heat travels through the atmosphere and escapes into space Stage 3: Some of this heat is absorbed by greenhouse gases in the atmosphere and so is reflected back to Earth. This causes the temperature of the Earth to rise Stage 4: Increased levels of greenhouse gases in the atmosphere trap more of the emitted heat. This leads to a greater increase in hte Earth’s temperature

Water vapour, methane and sulphur dioxide

Rising sea levels Shrinking ice caps More extreme weather Malaria moving northwards Species going extinct More extreme heatwaves Disruption to the gulf stream

23 times

Frozen plants and soil

Permafrost melts Plants go to the bottom of lakes Plants ferment and produce methane Methane gets trapped in ice Ice melts and methane is released into atmosphere

Iron seeding Converting CO2 into hydrocarbons Hydrogen fuel Carbon capture and storage

Putting iron in the oceans to stimulate phytoplankton growth. The increased amount of phytoplankton will then photosynthesise more, reducing carbon dioxide and increasing oxygen in the atmosphere

A fuel that does not produce any greenhouse gases when reacting with oxygen, only water. However, it is currently made by reacting steam with natural gas or coal, both of which are greenhouse gases. It is also very flammable and may explode if handled incorrectly

Reacting CO2, water and sunlight produces carbon and hydrogen, which can be combined to make hydrocarbon, which can be used as a fuel