Question - Analyse the data to describe the relationship between carbon dioxide levels and global temperatures.

Analyse the data to describe the relationship between carbon dioxide levels and global temperatures.

Answer: 

There is a strong positive correlation between carbon dioxide levels and global temperatures.

There have been fluctuating cycles that can be attributed to global warm ages and ice ages.

CO2 levels are the highest ever recorded (however CO2 increases may not always precede temperature increases).

Question - Explain how increasing concentrations of atmospheric carbon dioxide threatens coral reefs.

Explain how increasing concentrations of atmospheric carbon dioxide threatens coral reefs.

Answer: 

Increased concentrations of dissolved carbon dioxide lowers ocean pH (more carbonic acid = more acidity).

More hydrogen ions also means there are less free carbonate ions for calcification (shell formation).

Hence, an increase in water acidity correlates with significant thinning of calcium exoskeletons.

Low pH conditions are also detrimental to polyp survival, leading to coral bleaching.

Question - Describe the changes in atmospheric carbon dioxide levels detected at the Mauna Loa Observatory.

Describe the changes in atmospheric carbon dioxide levels detected at the Mauna Loa Observatory.

Answer: 

Carbon dioxide levels fluctuate annually (lower in summer = higher photosynthetic rate) Carbon dioxide levels are steadily increasing (due to increased burning of fossil fuels) Global trends conform to northern hemisphere (due to more people and more land mass) CO2 levels are now the highest ever recorded

Question - Explain the relationship between greenhouse gases and the greenhouse effect.

Explain the relationship between greenhouse gases and the greenhouse effect.

Answer: 

The greenhouse effect functions to trap heat within the atmosphere and prevent rapid temperature changes Incoming radiation (from the sun) is shorter wave radiation (e.g. ultraviolet radiation and visible spectrum) The Earth’s surface absorbs this radiation and re-emits it at a longer wavelength (i.e. infrared radiation / heat) Greenhouse gases absorb and re-radiate the longer wave radiation and hence retain heat in the atmosphere The higher the concentration of greenhouse gases in the atmosphere, the more heat is retained.