1.1 Global warming and climate change

Question 1

How does greenhouse gases such as carbon dioxide and methane, help maintain a steady temperature in the earths atmosphere?

Answer 1

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.

Question 2

What are some anthropogenic sources of carbon dioxide?

Answer 2

Burning of fossil fuels and deforestation.

Question 3

What are some natural sources of carbon dioxide?

Answer 3

Aerobic respiration, aerobic decay of organic matter.

Question 4

What are some anthropogenic sources of methane?

Answer 4

Rice fields, intense livestock farming.

Question 5

What are some natural sources of methane?

Answer 5

anaerobic decomposition of organic matter, cows.

Question 6

What are some natural sources of nitrous oxide?

Answer 6

Denitrification in natural vegetation in the soil and oceans.

Question 7

What are some anthropogenic sources of nitrous oxide?

Answer 7

nitrogen based fertilisers, internal combustion engines.

Question 8

Human sources of CFC’S

Answer 8

refrigerators, air conditioning, aerosols and foaming agents.

Question 9

Why are concentrations of greenhouse gases increasing?

Answer 9

anthropogenic activities, as less thermal energy is escaping the earths atmosphere, and is causing a thermal imbalance.
This forms a new equilibrium.

Question 10

What are some environmental consequences due to an increase in greenhouse gases?

Answer 10

1. declining sea and land ice.
2. rising sea levels and oceans warming.
3. Extreme weather events.

Question 11

What are the chemical reactions which take place, making the ocean more acidic?

Answer 11

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

Question 12

What is the formula for finding the concentration of H3O+?

Answer 12

[H3O+] = 10-pH

Question 13

What is the formula for finding the concentration of OH_.

Answer 13

[OH-] = 10-pOH

Question 14

What is the formula for calculating the pH?

Answer 14

pH = - log [H3O+]

Question 15

what is the formula for calculating the pOH?

Answer 15

pOH = - log [OH-]