More Environmental Problems Flashcards
What gases act like an insulating layer in the atmosphere?
Carbon Dioxide, Methane and water vapour
What are gassed such as carbon dioxide, methane and water vapour called?
Greenhouse gasses
What do greenhouse gasses do? Why do they naturally act as an insulating layer in our atmosphere?
They absorb most of the heat that would normally be radiated out into space, and re radiate it in all directions - including back towards the earth
What type of activity effects the amount of greenhouse gases in the atmosphere?
Human activity
E.g deforestation
The Earth is gradually heating up. There’s a correlation between this and what else?
The amount of CO2 in the atmosphere
Although the Earth’s temperature varies naturally, what is the scientific consensus?
Human activity is influencing this and causing a climate change
How does deforestation increase the level of carbon dioxide in the atmosphere?
- CO2 is released when trees are burnt (Carbon in wood is ‘locked up’ and doesn’t contribute to atmospheric CO2 - until it’s released by burning)
- Microorganisms feeding on bits of dead wood release CO2 as a waste product of respiration
- Living trees use CO2 for photosynthesis, removing these trees means less CO2 is removed from the atmosphere
How does burning fossil fuels increase the level of carbon dioxide in the atmosphere?
Releasing ‘locked up’ carbon into the atmosphere as CO2. The carbon was locked up in the fossil fuels when plants and animals were crushed over millions of years.
What are two ways scientists have been researching ways to restore the balance and limit the increase in CO2 level in the atmosphere?
Iron Seeding
Converting Carbon Dioxide into Hydrocarbons
Explain Iron Seeding
- Iron is an element needed by plants for photosynthesis. Injecting iron into the upper ocean promotes the growth of phytoplankton.
- These blooms of phytoplankton absorb CO2 from the atmosphere for photosynthesis.
Positives and negatives of Iron Seeding
+ This could help get things back in balance
- No way of controlling what plankton grows, some is toxic.
- Microorganisms that decompose dead plankton use up oxygen and this creates ‘dead zones’ in the ocean where nothing can live
Explain Converting Carbon Dioxide into Hydrocarbons
Chemists are researching the possibility of converting waste CO2 into hydrocarbons.
•high pressure, high temperature and a metal catalyst.
•short chain hydrocarbons can be generated fairly easily but the longer hc’s required for petrol are more difficult to produce
Positives and negatives of Converting Co2 into hydrocarbons
+ Would make a dent in the excess of CO2
- Only if the conversion process used ‘green’ energy
The temperature of the Earth is a balance… between what?
The temperature of the Earth is a balance between the heat it gets from the sun and the heat it radiates back out into space
