The extent of usable land will decline due to rise in sea levels. Many islands will be disappeared. People might have to carry oxygen tanks to breathe. Technological development won't go any further. Fossil fuels will completely be banned. Life expectancy may be lowered due to pollution, epidemics etc. Remaining people might live a simpler life with the only intention of survival. All the countries will have to unite and work towards a common goal. That is just to survive for few decades. What do you think?