BRUSSELS (REUTERS) - The number of trees damaged by air pollution, drought and other harmful factors has doubled over the past decade, according to an annual report on the state of Europe‘s forests published on Monday. By last year, just over a quarter of Europe‘s conifers and broadleaves were classed as damaged, having lost more than 25 percent of their leaves, said the report entitled Forest Condition in Europe , published jointly by the European Commission and the United Nations Economic Commission for Europe. Nearly 40 percent of trees were classified as at the warning stage , while slightly more than 35 percent of tress were considered healthy. The 1998 report comes three days after the European Union‘s statistical office Eurostat published new data on the role of forestry in curbing global warming by absorbing the powerful greenhouse gas carbon dioxide. The annual reports are part of an international programme set up in 1985 to monitor and evaluate the impact of air pollution on forests, set up under the Geneva Convention on Long-Range Transboundary Air Pollution.