Human activities which contribute to an increase in greenhouse gases in the atmosphere
Practise 30 exam-style questions on Human activities which contribute to an increase in greenhouse gases in the atmosphere for AQA GCSE Chemistry. Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.
30 questions
1–6 marks each
Instant marking
No sign-up needed
20 questions, marked as you go
Sample questions with model answers
Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.
Question 1
2 marks
Give two human activities that increase the amount of methane in the atmosphere.
Model answer
Cattle farming and the decay of waste in landfill sites.
Explanation
Methane is produced when microorganisms break down organic matter without oxygen, which happens in the digestive systems of cattle, in flooded rice fields and in landfill sites. Burning fossil fuels is not correct here because complete combustion produces carbon dioxide, not methane.
Suggest why emissions of greenhouse gases have increased as the world's population has grown.
Model answer
More people need more energy, so more fossil fuels are burned, releasing carbon dioxide. More food is also needed, so more cattle and rice are farmed, releasing methane.
Explanation
Each mark needs an activity linked to a greenhouse gas. Population growth increases the demand for energy, food and land, which drives emissions of both carbon dioxide and methane.
Mark scheme
1 mark
more energy needed, so more fossil fuels burned, releasing carbon dioxide
max 2
1 mark
more food needed, so more cattle / rice farming, releasing methane
1 mark
more waste in landfill, releasing methane
1 mark
more land cleared / deforestation, releasing carbon dioxide
Question 3
3 marks
Describe uncertainties in the evidence that scientists use to show that the Earth's mean surface temperature has increased since 1850.
Model answer
In the past far fewer temperature measurements were made and the instruments were less precise, so older records are less accurate. The measurements were not evenly spread around the world - there were few readings over the oceans and polar regions. Some weather stations are now in towns that have grown and become warmer, which can affect the readings.
Explanation
Uncertainty does not mean the evidence is wrong; it means there is a range of possible values. Scientists reduce uncertainty by using many measurements from many places and by checking results through peer review.
Mark scheme
1 mark
fewer measurements were made in the past / historical records are less accurate
max 3
1 mark
older instruments were less precise / methods of measuring have changed
1 mark
measurements were not evenly spread around the world (e.g. few over oceans, poles or deserts)
1 mark
older data from ice cores or tree rings are estimates / indirect
1 mark
local effects, e.g. weather stations in towns that have grown warmer
1 mark
natural year-to-year variation makes the trend harder to see
Question 4
4 marks
A newspaper headline says: 'Coldest winter in 30 years proves global warming is a myth'. The article is based on temperatures recorded in one town during one winter.
Evaluate the quality of the evidence used in the article.
Model answer
The evidence is poor quality. Temperatures from one town do not represent the whole Earth, and global warming refers to the mean temperature of the whole planet. One winter is far too short a period, because weather varies naturally from year to year while climate change is a trend over decades. The article has not been peer reviewed and may be biased, so it does not show that global warming is a myth.
Explanation
Judge evidence by how much data there is, how representative it is, how long a period it covers and whether it has been checked by other scientists. A single cold winter in one place tells us about weather, not about the global climate.
Mark scheme
1 mark
one town is not representative of the whole Earth / global temperature is an average for the whole world
max 4
1 mark
one winter is too short a period; climate change is a long-term trend over decades
1 mark
weather varies naturally from year to year (weather is not the same as climate)
1 mark
very small amount of data / only one set of measurements
1 mark
not peer reviewed / may be biased or based on only part of the evidence
1 mark
judgement: the evidence is poor quality and does not support the claim
Ready to try the rest? Every answer you write is marked against the mark scheme, so you can see exactly where the marks are.
Ctrl + Enter to check
AI TutorHints first, answers after you try
Hi! Stuck? Ask me for a hint and I’ll help you work it out. Once you’ve checked your answer I can explain exactly where the marks are.
