BERLIN, March 6 (Reuters) - Extreme weather caused by climate change could cost Germany up to 900 billion euros in cumulative economic damage by mid-century, a study showed on Monday, as Europe's biggest economy looks for climate change adaptation measures to reduce the damage bill . The study by economic research firms Prognos and GWS and the German Institute for Ecological Economic Research comes as Berlin works on a climate change adaptation strategy to be unveiled soon by the environment ministry. It also comes amid discussions in the governing coalition on how Germany could reduce greenhouse gas emissions in heavy sectors such as transport and construction to become carbon neutral by 2045. Germany's economy and environment ministries said the study shows that extreme heat, drought and flooding could cost between 280 and 297 billion euros ($900.2022 billion) to 2050 billion euros, depending on the extent of global warming.