The collapse of an old world

Year 2060. The melting of the ice has caused the sea level to rise and the main cities of the world are under water: New York, Buenos Aires, London, Rome, Barcelona, Cairo, Beijing, Tokyo, Sydney... are nothing but rusty reminiscences alongside the fish.
Although it has not been possible to avoid this catastrophe, a technology that influences the climate has been developed and has managed to paralyze the climate chain reaction by regulating the level of CO2 in the atmosphere.
The survivors
The survivors of the disaster form a global mass of refugees while the cities on high ground have become fortresses where a semblance of normality is experienced. Refugees live in camps on the other side of city walls, or in formerly abandoned villages. Strategic points like mines and nuclear power stations are exploited by private companies or protected by the army.
In the cities, the political system is a semblance of democracy, but all information is filtered by the authorized media. Global communication infrastructures have been lost, and the planet has suffered a recession. The Internet is an urban network for the wealthy classes. Communication with the outside world is controlled. Old religions have gained strength but new sects and heresies related to non-polluting forms of life have emerged.
In the midst of despair, hope appears. Eloy de la Llave, anthropologist, and psychologist specialized in lucid dreams, discovers, and perfects a method that allows communication through sleep.
A new way of communication
After the fall of the global communication networks, the method becomes popular by opening a new way of communication among dreamers, who can control what they dream and create an oneiric noosphere where they can live a second life. Two realities are generated: Oniria and Awakeland.
Most people who use the De La Llave method are refugees. Some of them have achieved a prosperous life in Oniria in exchange for spending most of their time sleeping. Only a few manage to do business in both realities.
The currency of payment in Oniria is the aerena, "the stuff that dreams are made of". Each person generates it naturally while sleeping, but it can be donated, spent, earned, and stolen. In addition, the rhythm at which it is generated is different in each person. It is possible to "drain" the dreamers: there are mafias in Awakeland that maintain farms of sleeping people to steal it and resell it on the black market. In this new world, dreams can be deadly…
