Climate traced to changes in land, plants, and animals
WASHINGTON - Human-generated climate change made flowers bloom sooner and autumn leaves fall later, turned some polar bears into cannibalism, and some birds into early breeders, a vast global study reported yesterday.
Hundreds of previous studies have noted these specific changes and most suggested a link to so-called anthropogenic global warming, but a new analysis published in the journal Nature correlated these earlier studies with changes in temperature, the study's lead author said.
Between 1970 and 2004, there was a close relationship between temperature shifts and changes in plants, animals, and the physical world, such as the retreat of glaciers and the water level in desert lakes, the study found.
"When you look at all of the glaciers and all of the snowpack and all of the birds laying eggs earlier and all of the plants having spring earlier across a continent, then we see we can detect anthropogenic signals," said Cynthia Rosenzweig of NASA's Goddard Institute for Space Studies.
They worked to rule out observed changes that could have been caused by other factors besides anthropogenic climate change.
Building on research done to support findings reported in 2007 by the United Nation's Intergovernmental Panel on Climate Change, Rosenzweig and her co-authors brought together nearly 30,000 sets of data about biological and physical changes around the world, and then matched that up with a database of global temperature change.
The link between human-caused global warming - generated by industrial and vehicle emissions of carbon dioxide to produce a temperature-boosting greenhouse effect - and observed biological and physical changes is very strong, Rosenzweig said.
