Shangri-La

The story takes place in the middle of the 21st century when global warming has turned Tokyo into a tropical city. To reduce the temperature at the heart of the city by 5°C (9°F), the city is being reborn as the world's largest forest city. However, despite the flow of refugees to the new city of Atlas, there are not many residents who can actually live there. Moreover, anti-government guerillas are attempting to stop the forestation. (Taken from Manga-Updates)