The Earth's temperature has reached its highest level in thousands of years, which has begun to affect plants and animals, according to a report published in Tuesday's issue of Proceedings of the National Academy of Sciences.

According to the study that analyzed temperatures around the globe, researchers from NASA's Goddard Institute for Space Studies in New York, found that the Earth has been warming at a rate of 0.36 degree Fahrenheit (0.2 degrees Celsius) per decade in the last 30 years.

That brings the overall temperature to the warmest in the current interglacial period, which began about 12,000 years ago, said James Hansen, who led the research team.

The researchers noted that 1,700 plant, animal and insect species moved poleward at an average rate of about 6.4 km per decade in the last 50 years.

The warming has been stronger in the far north, where melting ice and snow expose darker land and rocks beneath allowing more warmth from the sun to be absorbed more over land than water.

Water changes temperature more slowly than land because of its greater capacity to hold heat, but the researchers said that warming has been marked in the Indian and western Pacific Oceans. Those oceans have a major effect on climate and warming that could lead to more El Nino episodes affecting the weather.

Hansen warned that this evidence has implied that "we are getting close to dangerous levels of human-made pollution."

(Xinhua News Agency September 26, 2006)