A study found climate change is affecting Earth's natural systems

Significant changes to the Earth's natural systems are already happening as a result of man-made climate change, a large-scale scientific study has concluded.

Some 90% of changes in biological and physical systems - ranging from shrinking glaciers to earlier springs - can be attributed to a warming climate, the research published in journal Nature said.

The scientists said the changes were occurring in regions that were observing temperature increases, and that these continental-scale rises could not be attributed solely to natural variability.

Building on work by the Intergovernmental Panel on Climate Change (IPCC), which last year said it was "very likely" that global warming was man-made, the researchers said human-induced climate change was having a "significant" impact on natural systems globally and on some continents .

The researchers also said the effects of climate change outweighed other drivers such as land-use change and population.

The study's lead author Cynthia Rosenzweig said: "Humans are influencing climate through increasing greenhouse gas emissions and the warming world is causing impacts on physical and biological systems that are now attributable at the global scale and in North America, Asia and Europe."

The study analysed other research covering more than 29,500 sets of data stretching back to 1970. Some 829 documented physical changes - such as melting permafrost and increases in coastal erosion - had occurred and 95% of them were consistent with what would be expected from warming.

And 90% of around 28,800 changes seen in plants and animals were consistent with responses to temperature changes, such as flowering earlier.

Professor David Karoly, from the University of Melbourne and one of the study's authors, said: "It was a real challenge to separate the influence of human-caused temperature increases from natural climate variations or other confounding factors, such as land-use change or pollution.

"This was only possible through the combined efforts of our multi-disciplinary team, which examined observed changes in many different systems around the globe, as well as global climate model simulations of temperature changes."