Global warming has been going on for thousands of years.
That’s from a new academic article by a team that includes UNLV geoscientists, one of whom spent months in Russia gathering rare stalagmite samples that were later tested in a lab.
Along with scientists from Russia and other parts of the United States, Matthew Lachniet, professor of geoscience, and doctoral student Jonathan Baker say they have evidence that global warming has been an ongoing process for the last 11,000 years.
The two told State of Nevada that while some might use this to discount global warming as a natural phenomenon, the rate of warming in the last century or so is so much faster, they have no doubt manmade hydrocarbons are speeding up the process.
Baker was in Russia in the Ural Mountains in 2012 and 2013 with other scientists gathering ancient stalagmite samples from a cave so remote it took him 33 hours to get to it.
Stalagmites are formed by the dripping of water. The ice-cold caves preserve the water layer by layer in conical formations that arise from the cave floor. Each layer can then tell a story about the weather, based on its chemical composition.
“Caves are interesting natural laboratories. They are essentially storage facilities,” Baker said.
Baker and Lachniet said that by analyzing those layers, they were able to determine that global warming has been an ongoing process for thousands of years.
“If you compare what’s happening over the last century or two to what happened over the last 120 centuries in our record," Baker said, "Today looks nothing like those past 11,000 years.”
Lachniet said the findings show the earth has been warming slowly since the last Ice Age, then it was slowly cooling again because of a small change in the earth's orbit, but that changed and a natural warming started which has been aggravated by greenhouse gases.
“What that means from a practical perspective is that any additional warming, which is due to greenhouse gases is going to superimposed upon a natural warming,” he said. He said climate change is working like a "double whammy" for that part of Russia.
Perhaps, the most important use for the research is that it can be used to test climate models, which tell us what our climate is going to look in the future.
“This study drastically increased our confidence in climate models," Baker said, "Climate models we use to forecast what’s going to happen in the coming decades and the coming centuries if we continue to change the atmosphere has we have been.”
Researchers put past climate information into the climate models and when it correctly predicts what they know happened in the past, they know the model they've developed is correct. Baker said the information gathered and analyzed from the cave reaffirms research on climate change.
Lachniet put it simply: “If we ignore rising greenhouse gas concentrations in the atmosphere the global temperature is going to rise. We’re going to melt ice and snow that’s stored on the lands and sea levels are going to rise. There is no question about that.”
Their paper was published in the most recent issue of Nature Geoscience.
Matthew Lachniet, UNLV professor of geoscience; Jonathan Baker, UNLV doctoral student
