Atmospheric Chemistry Flashcards
What are the percentages in today’s atmosphere?
1% other gases - water vapour, noble gases, carbon dioxide
21% oxygen
78% nitrogen
Why are carbon dioxide levels increasing?
Because we’re burning fossil fuels.
Early atmosphere
Around __ billion years ago the earth was a ball of _____, hot rock.
The surface of the earth was made up at mainly __________, which released gases like carbon dioxide, ________ and water vapour into the atmosphere.
4.5
Molten
Volcanoes
Nitrogen
How were oceans formed?
Water vapour cooling and condensing.
How was oxygen produced?
Plants produced oxygen by photosynthesis.
How did carbon dioxide decrease?
CO2 was absorbed by plants and algae.
CO2 dissolved in the oceans - impacting marine animals.
CO2 became ‘locked up’ in rocks and fossil fuels.
Describe and explain how the earth’s atmosphere has changed over 4.5 billion years:
[6]
The early atmosphere had nitrogen, carbon dioxide and water vapour, whereas now it has oxygen and nitrogen.
This has happened because plants and algae have absorbed carbon dioxide, also carbon dioxide has been ‘locked in’ by rocks.
Another change is that the early atmosphere has no oceans, whereas now it does.
This has happened because, water vapour from the atmosphere has been condensed.
Finally, the early atmosphere also had no oxygen. However, now we have oxygen, so that we’re able to live on earth. This happened because plants produced photosynthesis, which gave out oxygen.
Where does carbon monoxide come from, and what environmental impact does it have?
From: fuels not burning properly.
Impact: poisonous gas.
Where does particulate come from, and what environmental impact does it have?
From: former as a byproduct of incomplete combustion.
Impact: global dimming.
Where does nitrous oxides come from, and what environmental impact does it have?
From: burning fuels at very high temperatures.
Impact: effects on human respiratory system.
Where does sulfur dioxide come from, and what environmental impact does it have?
From: burning fossil fuels that have sulfur in them.
Impact: acid rain.
Where does carbon dioxide come from, and what environmental impact does it have?
From: burning fossil fuels.
Impact: greenhouse gases, heats up earth. (Global warming)
Greenhouse gases like c______ dioxide, m_______ and water v_______ act like an i________ later in the earth’s atmosphere - this amongst other factors, allows the earth to be w_____ enough to support life.
Carbon Methane Vapour Insulating Warm
All particles a______ certain frequencies of radiation.
Greenhouse gases _____ absorb the incoming s_________ radiation from the sun - but they ___ absorb the long-wave radiation that gets r________ back off the earth.
Then they re-________ it in all directions - including back towards the ________.
The long-wave radiation is ________ radiation, so it results in warming of the surface of the earth.
This is the ___________ effect.
Absorb
Don’t
Short-wave
Do
Reflected
Radiate
Earth
Thermal
Greenhouse
Some forms of human activity affect the amount of greenhouse gases in the atmosphere:
(4 effects)
Deforestation - fewer trees means less CO2 is removed from the atmosphere via photosynthesis.
Burning fossil fuels - carbon that was ‘locked up’ in these fuels is released as CO2.
Agriculture - more farm animals produce more methane through their digestive process.
Creating waste - more landfill sites and more waste from agriculture means more CO2 and methane released by decomposition it waste.
Greenhouse effect simplified:
- Sun rays _______ earth’s atmosphere.
- Heat is _______ back from the earth’s surface.
- Heat is _______ by CO2 and as a result gets ________ in the atmosphere.
- The earth becomes ________.
Enter
Reflected
Absorbed
Trapped
Hotter
What are the effects of climate change?
Trapped energy warms earth Icecaps melting Sea levels rising (flooding) Extreme weather Droughts Some species go extinct
An increase in global temp could lead to polar ice caps melting - causing a rise in sea levels, increasing flooding and coastal erosion.
Propane + _______ -> carbon dioxide + ______
Oxygen
Water
Changes in rainfall patterns (the amount, timing and distribution) may cause some regions to get too much or too little ______.
This’ along with the changes in _______, may effect the ability of certain regions to produce food.
Water
Temp
The frequency and severity of storms may increase:
Changes in temp and amount of water available in a habitat may affect wild species, leading to differences in their distribution.
How to reduce carbon footprints (CO2 emissions):
Renewable energy sources or nuclear energy could be used instead of fossil fuels.
Using more efficient processes could conserve energy and cut waste. Lots of waste decomposes to release methane, so this will reduce methane emissions.
Governments could tax companies or individuals based on the amount of greenhouse gases they emit - e.g taxing cars based on the amount of CO2 they emit over a set of distance could mean that people choose to buy ones that are more fuel-efficient and so less polluting.
Reasons why actions to reduce carbon footprints may be limited:
- It’s easy enough saying that we should cut emissions, but actually doing it is harder.
- There’s still a lot of work to be done on alternative technologies that result in lower CO2 emissions.
- A lot of governments are also worried that making these changes will impact on the economic growth of communities - which could be bad for people’s wellbeing. This’ particularly important important for countries that’re still developing.
- Because not everyone is on board, it’s hard to make international agreements to reduce emissions. Most countries don’t want to sacrifice their economic development if they think that others won’t do the same.
- Individuals in developed countries need to make changes to their lifestyles. But it might be hard to get people to make changes if they don’t want to and if there isn’t enough education provided about why the changes are necessary and how to make them.
