Their progress and wealth is highly dependent on the harvests, and the price of grain. They probably have to import some industrial products and if they had a bad year (weather, other catastrophies, poor technology) they can't get the necessary amount of industrial products in exchange for their surplus e. g. in grain. There are so many standards and requirements about the quality of food production that no country can survive solely on agriculture without high quality technology (machines, unharmful fertilizers, research-based breeding, etc.).
Answer:
The permanent base level of a sea is the lowest level to which a sea can erode a landmass. The sea is a overflowing water 24/7 the tides also play a role
The atacama desert is west of the andes mountains.
The burning of fossil fuels like oil, gas or coal. The exhaust fumes from your vehicles. The mismanagement of landfill waste caused by garbage pollution. The harmful fragrance or off-gasing from plastic production, paints and so on