Concept:
- The need for sustainability appears when the way we develop today takes something away from tomorrow.
- That loss shows up in three places, in the stock of resources, in the state of the environment, and in the prospects of the next generation.
Step 1: The loss in the stock of resources.
Crude oil, coal and minerals are non-renewable, so every barrel burnt is one that will never exist again. The known reserves of crude oil would last only a few decades at present rates, yet industry, transport and electricity all depend on such fuels.
Growth built on a shrinking stock cannot be maintained.
Step 2: The loss even in renewable resources.
Groundwater can renew itself through rain, but only if withdrawal stays within what the rain replaces. In India that limit has been crossed in about one third of the country, and 300 districts have reported the water table falling by more than four metres in twenty years.
A renewable resource, used carelessly, behaves like a non-renewable one.
Step 3: The loss in the environment.
Industrial and agricultural growth has polluted the air and the rivers, cleared forests and damaged the soil. These are not things that can be bought back later with money, however large the income of the country becomes.
Step 4: The loss to those who come after us.
Each of the losses above is passed on. The next generation inherits less water, less fuel, poorer soil and a dirtier environment, and therefore fewer chances than we had.
Sustainable development simply means refusing to hand on that bill.
Final Answer: The issues are the exhaustion of non-renewable resources, the overuse of groundwater beyond what rainfall can replace, and serious environmental damage, all of which reduce what the coming generation will have. That is why development has to be made sustainable.