C13 The Earth's Atmosphere Flashcards
Describe the current composition of the Earth’s atmosphere, compared to the early atmosphere
78% Nitrogen
21% Oxygen
1% Other gases (Carbon dioxide, water vapour and noble gases e.g. Argon)
Back then
- Mostly CO2
- Little Nitrogen
- Small amounts of methane and ammonia
How is coal formed?
Coal is formed from the remains of ferns and leaves, which don’t decompose (due to acidic conditions or a lack of oxygen). Over millions of years, the plant remains are covered with sediment and are compressed, high temperature and pressure creates coal
How is crude oil formed?
When plankton die and settle on mud on the sea bed. When oxygen isn’t present they don’t decompose, and over thousands of years they are compressed, and under high temperature and pressure, they turn into crude oil
Where is natural gas normally found?
Near oil deposits, as natural gas is also formed from plankton
What is a similarity between all fossil fuels?
They all contain trapped carbon
Name 3 greenhouse gases
Water vapour
Methane
Carbon dioxide
Describe the greenhouse effect in terms of long and short wavelength radiation
- Energy from the sun travels to the Earth as short wavelength radiation (e.g. UV and visible)
- Some is reflected, while most passes through the atmosphere, as short wavelength radiation doesn’t
interact strongly with air particles - Energy of the radiation is absorbed when it reaches the Earth’s surface
- Earth’s surface radiates this energy as long wavelength radiation (e.g. Infrared)
- Some long wave radiation interacts with greenhouse gas particles in the atmosphere, and energy is
absorbed - As energy is trapped in the atmosphere, this causes the mean temperature of the atmosphere to
increase
What is a positive effect of l’effet de serre?
It keeps the temperature on Earth warm enough to support life, without the greenhouse effect, the Earth would be too cold for most organisms to survive
DONT FORGET COMPOSITION 6 MARKER
Describe some effects of climate change
- Melting glaciers, which cause sea levels to rise, and greater floods
- Greater/more storms
- More droughts
- Wildfires/ extreme weather
- Distribution of animals
- Coastal erosion
What is peer review and what are its benefits?
When scientists share results to critique them and assess validity. It allows scientists to detect false claims, e.g. those based on poor evidence and bias
Why is there a problem with our understanding of climate change?
It’s difficult to model and complex. So there are sometimes stories in the media that are simplified or biased, so scientists must work harder to communicate the correct truth to the general public.
Also we cannot predict with certainty how much the temperature of the Earth’s atmosphere will increase, and can lead to speculation
Describe ways in which humans are increasing the levels of Carbon Dioxide and Methane
(CO2)
- Deforestation
- Burning fossil fuels (in cars)
- Clearing land to farm animals
(CH4)
- Melting ice caps
- Beef farming (release methane in farts)
- Landfills
What is the definition of a “Carbon footprint”?
The total amount of carbon dioxide and other greenhouse gases, emitted over the full life cycle of a product, service or an event
Describe ways in which we can reduce our carbon dioxide emissions
- Insulating homes, as less fossil fuels are burnt to warm them
- Using public transport (Releases less CO2 per passenger)
- Using renewable sources of electricity
- Using energy saving lightbulbs, or turning appliances off when not used
What is the problem with trying to reduce people’s carbon footprint?
Most solutions are expensive, and many people are reluctant to pay. Some are also inconvenient
Describe ways in which people can reduce their methane footprint
- Eating less beef and dairy
- Trapping methane from landfills, and burning it to produce electricity
What is a fuel?
A substance that releases energy when burnt (Combusted)
Describe how Carbon monoxide is produced, and its effects
CO is formed through incomplete combustion, and is toxic, odourless and colourless, so many people have CO detectors in their homes
Describe how Sulfur Dioxide is produced, and its effects
- Some fuels e.g. coal contain sulfur, and when these are burned, sulfur atoms are oxidised, producing
the gas sulfur dioxide (S + O2 —> SO2) - They can cause breathing problems in humans
- Can dissolve in rainwater to produce acid rain which damages buildings, trees and ecosystems
Describe how Oxides of Nitrogen are produced, and their effects
- They are produced inside engines (e.g. in cars). High temperatures cause nitrogen and oxygen from the
air to react, and can produce a range of different molecules (NOx). - They can cause breathing problems in humans
- Can dissolve in rainwater to produce acid rain which damages buildings, trees and ecosystems
Describe how particulates are produced and their effects
- When particles of carbon (soot) and unburnt hydrocarbons are released into the atmosphere
- Can increase the risk of heart disease and lung disease
- They can reduce the amount of energy from the sun that reaches the Earth’s surface (global
dimming)
What is global dimming and give an effect
When particles reduce the amount of energy from the sun that reaches the Earth’s surface, which can disrupt rainfall patterns
State what the sedimentary rock limestone is formed from
From calcium carbonate deposits from the shells of and skeletons of marine organisms
How are sedimentary rocks formed?
From matter that is buried and compressed over millions of years
