Chapter 9: Chemistry of the Atmosphere [unfinished: p234] Flashcards
What percentage of air is nitrogen?
78%
What percentage of air is oxygen?
21%
Describe the Earth’s atmosphere soon after it formed
Mostly carbon dioxide, some nitrogen, no oxygen (Mars and Venus are like this). The atmosphere has been the same for the last 200 million years
What gases do volcanoes release?
Carbon dioxide, nitrogen, methane, ammonia, water vapour
Where did oxygen come from?
Cyanobacteria (which evolved 2.7 billion years ago) and plants, which can photosynthesise
Where did the carbon dioxide go?
CO2 that dissolved in oceans reacted to form sediment, or soluble compounds which animals took in and turned into shells etc. (which eventually became sediment). CO2 used in photosynthesis formed plants in swamps which decayed under heat and pressure forming coal. The same thing happened to plankton in the sea, which formed crude oil and natural gas instead
What is a greenhouse gas?
A gas that does not absorb radiation from the sun, but absorbs longer-wave radiation reflected off the earth, leading to global warming
What is causing an increase in carbon dioxide?
Deforestation, burning fossil fuels
What is causing an increase in methane?
Farm animals including cows, decomposing rubbish
What is peer-reviewed research?
Research that is studied and commented on by experts in the same area of science to check that it is scientifically valid
What do scientists think of global warming?
Most believe that increasing levels of gases will lead to climate change, but the climate is difficult to model due to there being factors that are not fully-understood
What are the effects of climate change?
The temperature of the Earth’s surface has increased by 0.5 degrees since 1985. This is causing ice to melt and water to expand, causing rising sea levels and flooding. Storms are occurring, and rainfall is increasing in some areas and decreasing in others, causing water stress. These effects are also harming wildlife, crops and other biological systems
What is carbon footprint?
The amount of greenhouse gas given off over the full lifetime of something
How can carbon footprint be reduced?
Using alternative energy sources, conserving energy (increasing insulation in houses, energy efficient engines and light bulbs), capturing carbon dioxide and storing it underground, carbon off-setting (planting trees and creating wind farms), taxes on fossil fuels, emission limits for companies [unfinished]
