Thursday, May 15, 2008

Warming Climate Is Changing Life On Global Scale

ScienceDaily (May 15, 2008) — A vast array of physical and biological systems across the earth are being affected by warming temperatures caused by humans, says a new analysis of information not previously assembled all in one spot. The effects on living things include earlier leafing of trees and plants over many regions; movements of species to higher latitudes and altitudes in the northern hemisphere; changes in bird migrations in Europe, North America and Australia; and shifting of the oceans' plankton and fish from cold- to warm-adapted communities.

"Humans are influencing climate through increasing greenhouse gas emissions, and the warming world is causing impacts on physical and biological systems attributable at the global scale," said lead author Cynthia Rosenzweig, a scientist at the NASA Goddard Institute for Space Studies and the Columbia Center for Climate Systems Research. Both are affiliates of The Earth Institute at Columbia University.

Observed impacts included changes to physical systems, such as glaciers shrinking, permafrost melting, and lakes and rivers warming. Biological systems also were impacted in a variety of ways, such as leaves unfolding and flowers blooming earlier in the spring, birds arriving earlier during migration periods, and plant and animal species moving toward Earth's poles and higher in elevation. In aquatic environments such as oceans, lakes, and rivers, plankton and fish are shifting from cold-adapted to warm-adapted communities.

Rosenzweig and researchers from 10 other institutions across the world analyzed data from published papers on 829 physical systems and some 28,800 plant and animal systems, stretching back to 1970. Their analysis of revealed a picture of changes on continental scales; previous studies had looked mainly at single phenomena, or smaller areas. In physical systems, 95% of observed changes are consistent with warming trends. These include wastage of glaciers on all continents; melting permafrost; earlier spring river runoff; and warming of water bodies. Among living creatures inhabiting such systems, 90% of changes are consistent with warming.