C13 The Earth's Atmosphere Flashcards
according to theory, what gases did volcanoes release into Earth’s early (first billion years) atmosphere
- volcanoes released NITROGEN, CARBON DIOXIDE and WATER VAPOUR,
- these gases formed the early atmosphere.
according to theory, how were oceans formed?
oceans formed from water vapour (from volcanoes) condensing
according to theory, what did the Earth’s early atmosphere mainly consist of?
which gases were there small proportions of?
mainly carbon dioxide
may have been small proportions of methane, ammonia and oxygen gas.
according to theory, how did the amount of carbon dioxide in the Earth’s early atmosphere decrease?
- when oceans formed, carbon dioxide dissolved in them
- locked up in sedimentary rock and fossil fuels,
- from 2.7 billion years ago, more and more bacteria and algae evolved, photosynthesising which released oxygen and took in (so reduced carbon dioxide).
how did animal forms start to evolve?
how did earliest living microorganisms react to this?
more plants evolved, more photosynthesis, more oxygen into atmosphere, allowing first animal forms to evolve, relying on algae and plants for food and oxygen to respire.
the earliest microorganisms had evolved without such high oxygen levels, so had little places to survive in and largely died out.
proportion of gases in atmosphere today
78% nitrogen
21% oxygen
0.9% argon
0.04% carbon dioxide
what type of radiation does the Earth’s surface emit?
long wavelength, infrared
what type of radiation do greenhouse gases let pass through?
which type do they absorb?
short wavelength can pass through
they absorb long wavelength, infrared
how do greenhouse gases increase the temp of Earth’s atmosphere?
they absorb long wavelength (infrared) radiation emitted from the Earth’s surface
the greenhouse gases trap the energy in the atmosphere
raising its temperature
how does methane get into the atmosphere?
- more cattle (from their decomposing waste),
- rice fields,
- swamps,
- landfill sites.
how has human activity increased the level of carbon dioxide in the atmosphere?
- burning fossil fuels releases carbon dioxide into atmosphere,
- deforestation means there are less trees to take it from the atmosphere for photosynthesis,
- climate change: temperature rises make carbon dioxide less soluble in water, so dissolve less in oceans.
what is carbon footprint?
the total amount of greenhouse gases emitted over the full life cycle of a product, service or event
how to reduce carbon dioxide emissions?
- use less fossil fuels,
- burn biofuels instead,
- use less electricity,
- plant more trees,
- home insulation to conserve energy,
- carbon capture and storage.
how to reduce methane emissions
- lower demand for beef, plant-based diets,
- lower landfill.
describe carbon capture and storage
-pump carbon dioxide released into atmosphere into underground fossil fuel power stations to be absorbed into porous rocks