9.2.2Human activities that increase greenhouse gases
AQA GCSE Chemistry (8462), Higher tier · Chemistry of the atmosphere › Carbon dioxide and methane as greenhouse gases
Practise Human activities that increase greenhouse gases. 12 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
(a) Give two human activities that increase the amount of carbon dioxide in the atmosphere.[2]
(b) Give two human activities that increase the amount of methane in the atmosphere.[2]
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(a)
burning fossil fuels (e.g. in power stations or vehicles)
deforestation / cutting down or burning forests
(b)
animal farming (e.g. cattle)
decomposition of rubbish in landfill sites
Question 2Medium5 marks
A newspaper article included this headline: 'Coldest winter in our town for 20 years — so global warming is not happening!'
(a) Explain why the conclusion in the headline is not valid.[2]
(b) Explain why it is important that research about climate change is peer reviewed.[2]
(c) Suggest one reason why reports about climate change in the media may be misleading.[1]
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(a)
one town / one winter is not representative of the whole Earth
climate change is about long-term trends in average global temperature (weather varies from year to year)
(b)
other (independent) scientists check the methods, data and conclusions
so errors or bias can be found and the findings are more likely to be valid
(c)
they may be based on only part of the evidence / may be simplified / may be biased / may present opinions or speculation as fact
Question 3Hard6 marks
{table} shows the mean carbon dioxide concentration and the mean global temperature anomaly for four decades. The temperature anomaly is the difference from the mean temperature for 1951–1980.
[object Object]
(a) Describe the relationship between carbon dioxide concentration and temperature anomaly shown in {table}.[1]
(b) A student said: 'These data prove that carbon dioxide from human activities causes global warming.' Evaluate the student's statement.[3]
(c) Scientists use computer models to predict future climate. Suggest two reasons why the predictions are uncertain.[2]
Show the answer and mark scheme
(a)
as the carbon dioxide concentration increases the temperature anomaly / mean global temperature increases
(b)
the data show a correlation between carbon dioxide concentration and temperature
a correlation does not prove that one causes the other / other factors could affect temperature (e.g. changes in the Sun's output, volcanic eruptions)
the data do not show where the carbon dioxide came from (human or natural sources)
there is a known mechanism (greenhouse gases absorb long wavelength radiation) and peer-reviewed evidence that supports a causal link
(c)
the climate is a complex system with many interacting factors
models are simplified
future emissions depend on human activity, which cannot be predicted exactly
some data are limited / measurements have uncertainties