Answer to Question 1
The climate and the quality of the environment are considered public goods because no one can be excluded from consuming these goods, and one person's consumption of either good does not reduce the quantity that is available to others. This means that, because it can be costly to protect the environment, a single person or country has little incentive to do so.
A-head: ECONOMICS OF CLIMATE CHANGE
Concept: Public goods, tragedy of the commons
Answer to Question 2
A shortage arises at market prices below the equilibrium price. A shortage causes the price to rise, decreasing quantity demanded and increasing quantity supplied until the equilibrium price is attained.
Body temperature and environmental temperature in homeotherms versus heterotherms.
Four hypotheses on how populations might relate to one another along an environmental gradient.
Air Quality Index
How to create a price index to calculate inflation for a basket of goods
Global Climate Change
Draw an Edgeworth box for two consumers over two goods