Why is global warming such a pressing issue facing society today?
It is a social economic issue.
the industrialized western nations are expected to cut back on their production manufactured goods to cut back on pollution. Also according to the Kyoto accords the western industrialized nations are suppose to provide economic resources to the less industrialized " third world " nations to allow them catch up in industrialization. It is a form of international socialism.
The increase in Carbon Dioxide in the atmosphere is changing the climate. Any change in the climate creates stress economically and environment. One theory as to why the dinosaurs died out is climate change. The climate during the age of the dinosaurs" was a climate that was very humid, with high levels of Carbon Dioxide. This created the conditions for the vast coal beds found throughout the world and for the deposits of oil and natural gas.
A gradual increase in global temperatures will increase the range of insects that die out in cold winters. This will increase diseases such as West Nile Virus, Ebola and Malaria. The human population will have to find ways of dealing with increases in epidemic diseases. ( Another theory is that the dinosaurs died of an epidemic.)
The changing climate will also affect agriculture. Some areas will become too hot for the present agriculture products. Others like Canada will become very productive agriculture centers. Some people will starve while others receive a bounty.
The gradual increase in temperature will change sea levels. Some cities built along the ocean will become uninhabitable. New cities further inland will have to be built. Do to decreasing sea levels the ancient city of Ephesus was rebuilt three times in order to remain a sea port and the oceans moved further away from the city. Global warming can reverse this trend. Rebuilding cities is an expensive proposition.
Global warming will create change. Change is always difficult for society to deal with. Some civilizations like the Maya dissolved because the civilzation could not deal with the change.