1.1 Global warming and climate change Flashcards
How does greenhouse gases such as carbon dioxide and methane, help maintain a steady temperature in the earths atmosphere?
Carbon dioxide and methane are greenhouse gases, that can absorb and emit thermal IR radiation. Some thermal IR radiation is reradiated back to earth, warming it, while the rest is lost in space.
What are some anthropogenic sources of carbon dioxide?
Burning of fossil fuels and deforestation.
What are some natural sources of carbon dioxide?
Aerobic respiration, aerobic decay of organic matter.
What are some anthropogenic sources of methane?
Rice fields, intense livestock farming.
What are some natural sources of methane?
anaerobic decomposition of organic matter, cows.
What are some natural sources of nitrous oxide?
Denitrification in natural vegetation in the soil and oceans.
What are some anthropogenic sources of nitrous oxide?
nitrogen based fertilisers, internal combustion engines.
Human sources of CFC’S
refrigerators, air conditioning, aerosols and foaming agents.
Why are concentrations of greenhouse gases increasing?
anthropogenic activities, as less thermal energy is escaping the earths atmosphere, and is causing a thermal imbalance.
This forms a new equilibrium.
What are some environmental consequences due to an increase in greenhouse gases?
- declining sea and land ice.
- rising sea levels and oceans warming.
- Extreme weather events.
What are the chemical reactions which take place, making the ocean more acidic?
carbon dioxide reacts with ocean water, forming carbonic acid.
CO2 + H2O. —-> H2CO3
Carbonic acid is a weak acid and partially ionises forming hydronium ions and hydrogen carbonate ions.
H2CO3. +. H2O. –> H3O+ +. HCO3-
Hydrogen carbon further ionises forming hydronium ions and carbonate ions.
HCO3- + H20. –> H3O+. +. CO3-2
an increases in hydronium ions = a decrease in ocean pH
What is the formula for finding the concentration of H3O+?
[H3O+] = 10-pH
What is the formula for finding the concentration of OH_.
[OH-] = 10-pOH
What is the formula for calculating the pH?
pH = - log [H3O+]
what is the formula for calculating the pOH?
pOH = - log [OH-]
