A new analysis published in Nature (May 15, 2008) revealed that a large number of physical and biological systems across the planet are being affected by global warming. The impacts range from earlier leafing of trees and plants, migration of species to higher latitudes, changes in bird migrations to change in distribution of fish communities in oceans. The researchers analyzed data from published studies on 829 physical systems and about 28,800 plant and animal systems, since 1970. The analysis revealed that changes are happening on continental scales. About 95 per cent of the observed changes in glaciers and water bodies were attributed to global warming. It also affects about 90 per cent of those living in these places. According to the study, changes are conspicuous in North America, Asia and Europe, as more studies have been done there to document the impact of global warming. On the other continents, South America, Australia and Africa, though there is good evidence of human-induced global warming, documentation of impact is poor, says the study.