For an assess question, you need to talk about advantages/disadvantages of the evidence with a judgement.
This means something like:
The Antarctic ice samples give an idea that there has been an increase in concentrations of SO2 and NOx in the atmosphere since the industrial revolution.
The evidence suggests that SO2 and NOx concentrations have been increasing.
-> As snow falls in Antarctica, the trapped air is characteristic of the atmosphere of the time and showing that concentration of SO2 and NOx has been increasing.
-> The deeper layers of ice suggest older age and the deeper layers tend to have less SO2 and NOx.
-> A comparison that then drawn and graphed over time.
-> Extra evidence from the 1960s onwards suggests that SO2 and NOx concentrations have been increasing over time.
There are also problems with the evidence used from Antarctica.
-> It was found that air can diffuse out of the ice samples causing concentrations to appear to change - this deteriorates its reliability and accuracy.
-> SO2 and NOx are mostly soluble in water causing them to dissolve and fume out of the ice samples causing further changes in concentration.
-> Before the 1960s, there are limited measurements due to technological limitations causing evidence to be difficult to back up for reliability.
Judgement: Even though there were problems with the evidence, the Antarctic ice samples gave a strong indication that NOx and SO2 concentrations have been increasing in the atmosphere over time, most likely beginning of the industrial revolution due to the combustion of fuels.
