Just over 10 years from now, residents of Athens and other major cities will have to endure more heat waves of a greater duration, significantly hotter nights and an increase in thunderstorms, according to the results of a study by conservation group WWF Hellas made public yesterday. According to the study into the impact of global warming on Greece’s climate, carried out by the Athens Observatory, the period between 2021 and 2050 will see an increase in extreme weather phenomena in major cities but also on islands and in rural areas. The temperature in Athens is forecast to exceed 35 degrees Celsius (95 Fahrenheit) on 10 to 15 days more per year than it does now and city-dwellers will have to endure at least 20 additional sweltering nights. Experts also expect a 10 percent increase in the incidence of heavy showers, resulting in greater flash flooding in cities and the provinces. Achilleas Plitharas, a spokesman for WWF Hellas, said the protection of dwindling green spaces and the creation of new ones might help to blunt the impact of global warming on climate change.