Greenhouse gases and thus temperatures are skyrocketing and will most likely reach epic proportions by the year 2100, scientists at Oregon State University and Harvard University have found.
Funded by the National Science Foundation’s Paleoclimate Program, and published in the March 8 issue of the journal Science, the study covers 11,300 years and finds temperatures higher than they have been over 70 to 80 percent of that time, OSU said in a statement on March 7.
A team headed by Shaun Marcott, a postdoctoral researcher in OSU’s College of Earth, Ocean and Atmospheric Studies, reached further back than most other studies, which he said usually don’t go beyond 2,000 years ago, to give the current climate change issues some context. They studied data from 73 sites around the world, to tell Earth’s temperature history back to the end of the last Ice Age. The current age, called the Holocene, began when the great ice sheets of northern Turtle Island and Europe receded. What they found may well heat up the climate change debate.
First, Earth cooled about 1.3 degrees Fahrenheit for most of the past 5,000 years, but warmed back up by the same amount over just the past 100 years, the researchers said. And the bigger the land masses and the larger the populations, the warmer it got—as in the Northern Hemisphere.
Predictions from climate change models expect the temperatures to increase another 2.0 to 11.5 degrees by the end of the century, the OSU statement said, “significantly greater than at any time during the past 11,300 years,” said Peter Clark, an OSU paleoclimatologist and co-author on the Science article, in the statement.
“We already knew that on a global scale, Earth is warmer today than it was over much of the past 2,000 years,” Marcott said in an OSU statement. “Now we know that it is warmer than most of the past 11,300 years. This is of particular interest because the Holocene spans the entire period of human civilization."
Moreover it’s an anomaly because of the speed with which it is happening, said Candace Major, the program program in the National Science Foundation’s Division of Ocean Sciences, which funded the research along with NSF’s Division of Atmospheric and Geospace Sciences.
Breaching the Holocene’s temperatures would be a first, the scientists said. Although 2000–2009 was one of the warmest since the U.S. started keeping records, the temperatures have been lower than the age’s overall. But no more.
“The last century stands out as the anomaly in this record of global temperature since the end of the last ice age,” said Majo in OSU’s statement. “This research shows that we’ve experienced almost the same range of temperature change since the beginning of the industrial revolution as over the previous 11,000 years of Earth history—but this change happened a lot more quickly.”