CO2 & CH4 as Greenhouse Gases Flashcards
All 26 cards in this deck
Name the three greenhouse gases you must know for AQA Chemistry.
Water vapour, carbon dioxide and methane.
Why are greenhouse gases in the atmosphere important for life on Earth?
They maintain temperatures on Earth high enough to support life.
What are the steps of the greenhouse effect?
e.g. radiation arriving from the Sun- Short wavelength radiation from the Sun passes through the atmosphere and is absorbed by the Earth's surface.
- The Earth's surface re-radiates energy as long wavelength (infrared) radiation.
- Greenhouse gases absorb this long wavelength radiation and re-radiate some of it back towards Earth, keeping the surface warm.
Which wavelength of radiation do greenhouse gases absorb?
Long wavelength (infrared) radiation, re-radiated from the Earth's surface.
True or false? Nitrogen and oxygen are greenhouse gases.
False. The greenhouse gases are water vapour, carbon dioxide and methane; nitrogen and oxygen are not.
True or false? The greenhouse effect is entirely caused by human activity.
False. The greenhouse effect is natural and necessary for life; human activity increases greenhouse gas amounts and so increases the effect.
Give two human activities that increase the amount of carbon dioxide in the atmosphere.
Burning fossil fuels and deforestation.
Give two human activities that increase the amount of methane in the atmosphere.
Farming cattle (livestock) and growing rice; also decomposition of waste in landfill.
How can an increase in world population have caused the increase in carbon dioxide concentration?
More energy and transport are required, so more fossil fuels are burned; more farmland is required, so there is more deforestation.
How can an increase in world population have caused the increase in methane concentration?
More food is required, so more methane-producing food production (e.g. cattle and rice); more waste is produced, which releases methane as it decomposes.
Why is peer review of climate change results important?
Other scientists check the evidence and conclusions, so the results are more likely to be valid and reliable.
Why may media reports about global climate change be unreliable?
They use simplified models and may present speculation or opinion based on only part of the evidence, so they can be biased.
Give one reason why some scientists do not accept that greenhouse gases have caused the rise in mean global temperature.
There may be other reasons for the temperature change, e.g. the Earth goes through natural cycles of temperature change.
What is stated to be a major cause of climate change?
An increase in the average (mean) global temperature.
Describe four potential effects of global climate change.
Melting ice, rising sea levels, flooding, more extremes of weather (also loss of habitats).
True or false? Acid rain is a potential effect of global climate change.
False. Acid rain is caused by sulfur dioxide and oxides of nitrogen, not by rising global temperature.
Why is it difficult to predict the effects of global climate change?
Global climate is a very complex system, so models of it are simplified and their predictions are uncertain.
What does a graph showing that both carbon dioxide concentration and mean global temperature have risen tell you?
There is a correlation between them, but correlation alone does not prove that carbon dioxide caused the temperature rise.
When judging the quality of the evidence in a report about climate change, what should you check?
Whether the data are peer reviewed, from a reliable source, and use all the evidence rather than a selected, biased part of it.
What is the carbon footprint of a product, service or event?
The total amount of carbon dioxide and other greenhouse gases emitted over its full life cycle.
True or false? A carbon footprint only measures carbon dioxide emissions.
False. It is the total of carbon dioxide and other greenhouse gases, such as methane, over the full life cycle.
Give two actions that reduce carbon dioxide emissions.
Use renewable energy or nuclear power instead of fossil fuels, and use carbon capture and storage; also improving energy efficiency.
Give two actions that reduce methane emissions.
Eat less beef so fewer cattle are farmed, and capture the methane given off by decomposing waste in landfill.
Give reasons why actions to reduce the carbon footprint may be limited.
Cost, lack of international/political agreement, lack of public information or education, and people being unwilling to change their lifestyle.
True or false? Reducing a carbon footprint to zero is usually easy for a country to achieve.
False. Reductions are limited by cost, technology, lack of international agreement and unwillingness to change lifestyles.
True or false? The carbon footprint of a product includes greenhouse gases emitted over its full life cycle, not just while it is being used.
True. The carbon footprint is the total carbon dioxide and other greenhouse gases emitted over the full life cycle of a product, service or event.