Abstract
The Earth's climate has warmed by approximately 0.6 ºC over the past 100 years with two main periods of warming, between 1910 and 1945 and from 1976 onwards. The effects of climate change on biodiversity are far-reaching and operate at many different levels from individuals to ecosystems. There is now ample evidence of the ecological responses of both flora and fauna. The current paper is highlighting some of these responses amongst wild species and natural communities, including changes in the phenology and physiology of organisms, the range shift of species and changes in the composition, structure and dynamics of ecosystems. Although we are only at an early stage of the projected trends of global warming, ecological responses to climate change are already visible. The evidence indicate that warmer temperatures at the end of the twentieth century have affected the phenology of organisms, the range and distribution of species, and the composition and dynamics of communities. Examples provided in the current study cover most major taxa and ecosystems on Earth; providing linkages between recently observed changes in natural systems and twentieth century climate change. More research is required to provide detailed mechanisms by which climatic change affects individual physiology, seasonal timing, population dynamics and geographic distributions. The implications of such large-scale, consistent responses to relatively low average rates of climate change are large and the projected warming for the coming decades raises even more concern about its ecological and also socio-economic consequences.