Researchers Say Earth is the Warmest It’s Been in 12,000 Years

A research team led by James Hansen of NASA’s Goddard Institute for Space Studies in New York has reported evidence that supports the theories of global warming. In Tuesday’s issue of Proceedings of the National Academy of Sciences, researchers say that the planet’s temperature has climbed over the last 30 years to levels not seen in nearly 12,000 years. The study said that recent global warming has brought the Earth’s temperature within only about 1.8 degrees Fahrenheit of the maximum temperature of the past million years.

The team found that the Earth has been warming at a rate of .36 degrees Fahrenheit per decade—more than 1 degree in the last 30 years. These increases mean the planet is the warmest it has been in the current interglacial period, which began 12,000 years ago. Warming has been stronger in the far north pole of the planet, where melting snow and ice expose the darker land beneath, allowing the sun’s warmth to penetrate more easily over land than water.

Because of its great capacity to hold heat, water usually changes temperature more slowly than land. But researchers noted that warming has been particularly dramatic in the western Pacific and Indian Oceans. Because those two oceans have a major impact on climate, the warming could lead to more El Nino episodes affecting the weather in the years to come.

Hansen and his team found that 1,700 species of animals, insects, and plants have moved farther northward at an average rate of about 4 miles per decade over the last 50 years. "This evidence implies that we are getting close to dangerous levels of human-made pollution," said Hansen, one of the first researchers to speak out about global warming decades ago. Hansen said that the greenhouse gases produced by humans have become the primary factor resulting in climate change, which is causing dangerous damage to our atmosphere.

"If further global warming reaches 2 or 3 degrees Celsius, we will likely see changes that make Earth a different planet than the one we know," Hansen said. "The last time it was that warm was in the middle Pliocene, about 3 million years ago, when sea level was estimated to have been about 25 meters (80 feet) higher than today."