OSLO, March 22 (Reuters) - Stresses on water supplies aggravated by climate change are likely to cause more conflicts and water should be considered as vital to national security as defence, a United Nations report said on Friday.

About 145 nations share river basins with their neighbours and need to promote cooperation over a resource likely to be disrupted by more frequent floods and heatwaves, it said.

Europe has failed to learn the lessons from many environmental and health disasters like Chernobyl, leaded petrol and DDT insecticides, and is now ignoring warnings about bee deaths, GM food and nanotechnology, according to an 800-page report by the European Environment Agency.

Equitable, broad-based public access to sustainable, sanitary supplies of water is increasingly being seen as a security issue. A growing world population, global warming, growing fossil fuel use and greenhouse gas emissions and ongoing, growing disparities in the distribution of wealth and income and business-as-usual political economy – all threaten national, regional and international efforts to assure all members of society fair access to sustainable water resources.