1.

Question 1

1.1 How much energy from food

Answer 1

2-3 GJ per year.

Question 2

1.2 World energy use 4

Answer 2

1. World wide 80 GJ per capita per year.
2. Industrialised 100-220, US more Africa 10-20.
3. Relation between energy use and child mortality etc.
4. Increased GDP does not always lead to increased energy consumption.

Question 3

1.3 Environmental impact of energy use 3

Answer 3

1. Climat change
   a. The temperature at Earth’s surface is such that incoming and outgoing radiations are in equilibrium.
   b. CO2 absorbs infrared.
   c. Water vapour.
2. Acid deposition
   a. Caused by emissions of sulphur dioxid and nitrogen oxides from burning fossil fuels.
   b. Thermal NOx formation, above 1400 degrees, oxygen dissociates.
   c. Exhaust gas catalysts.
3. Local air pollution
   Emissions from combustion of fossil fuels.

Question 4

1.4 Security of energy supplies

Answer 4

Because of alternative energy and limiting CO2 fossil fuel will not be exhausted.

Question 5

1.5 Energy and sustainable development, four major challenges.

Answer 5

Four major challenges
a. Soaring greenhouse gas emissions
b. Decreasing energy security
c. Air pollution
d. Lack of universal access to energy services.