Final answer:
The absolute change in natural resources and environment spending from 2000 to 2019 cannot be calculated due to insufficient information provided.
Step-by-step explanation:
To calculate the absolute change in natural resources and environment spending from 2000 to 2019, we would subtract the 2000 spending amount from the 2019 amount. However, since the specific spending amounts for those years are not provided in the reference information, we cannot compute the absolute change, and the correct choice would be (d) Insufficient information to determine.
An international agreement may be necessary for countries to act on environmental protection since, without it, there is often no incentive for individual countries to bear the cost of environmental action which provides a collective benefit. This situation can be understood in the context of game theory, where the 'Nash equilibrium' might result in all countries choosing not to act, concluding with a suboptimal outcome for the environment.