Greenhouse effect and climate change

what is the purpose of the earth’s atmosphere

acts as an insulating blanket keeping in the perfect amount of the sun’s energy so that the earth stays at the right temperature all the time to maintain life

explain the greenhouse effect

1. sun’s energy comes down onto the earth as short wavelength radiation, it passes through the earth’s atmosphere and hits the surface of the earth and some of this energy is absorbed by the earth

2. however most of it is re-emitted or reflected back into the atmosphere into space as longer wavelength radiation

3. some of this energy however, hits particles of gas in our atmosphere which absorb the energy and re emit the energy in random directions

4. this process of being absorbed and re emitted by other gas particles happens over and over again meaning that the heat energy stays closer to earth for longer than if there was no atmosphere

5. this keeps the earth at a nice stable temp

what are the greenhouse gases in the earth’s atmosphere

methane

carbon dioxide

water vapour

what human activities are causing increased levels of methane

1. as the population on earth grows we need more food to sustain our growing population so increased farming of animals such as cows increases methane as they produce it during respiration so burp and fart it out

2. humans produce huge amounts of waste such as in landfills which release methane and when the waste decomposes the decomposers release carbon dioxide as they release the waste

what human activities are causing increased levels of carbon dioxide

1. burning of fossil fuels releases the carbon dioxide stored in them

2. deforestation —> less trees —> less photoS—> less carbon dioxide removed from the atmosphere

how do we know that the earth is getting warmer

because we have records going back hundreds of years and can see the steady increase

why are the consequences for global warming hard to know

because there are so many variables which makes it harder for scientists to make models of what will happen

define climate change

refers to the long term shift in temperatures and weather patterns/effects of global warming

define weather

day to day changes in the earth’s atmosphere, short term changes

why is peer reviewing important

to prevent false claims

what are the consequences of global warming

storms become more frequent and severe

droughts and famine become more common

sea level rise : as high temps cause glaciers to melt which will flow into the ocean and as the water in the ocean warms up it expands so its volume will increase making seal levels rise even more

submersion of entire islands and coastal cities due to rising sea levels

extinction of speices as rainfall and temps change species that were perfectly adapted might not be able to survive so biodiveristy falls rapidly

migration of species to other regions