Coal reserves are said to be enough to last for another hundred years. Do you think we need to worry in such case? Why or why not?

 Yes, we do need to worry about it as it is known that the resources of coal will last only for about 100 years. Once the present stock of coal present in the earth gets exhausted, no new supplies of these fossil fuels will be available to us in the near future because it takes millions of years to convert the dead organisms into fossil fuels in nature.