February 18, 2013
Tracking Climate Traces Through Dried Urine Analysis
Brett Smith for redOrbit.com - Your Universe Online
Not cleaning a kitty´s litter box could be a disgusting thought for cat owners, but for Brian Chase of Montpellier University in France – layers of dried urine can reveal exciting new details about an environment as they stack up year after year and generation after generation.
Instead of learning about the historical habitat of the common housecat, Chase and his colleagues from the European Research Council analyzed layers of dried urine from the rock hyrax, and found they could track the course of climate change throughout history.
The hyrax is a mammal that grows to roughly the size of a guinea pig and lives in the same rock fissures over the course of generations throughout Africa and Asia.
"Hyraxes use the same place to pee every day,” Chase told The Guardian. "The crucial point is that hyrax urine — which is thick and viscous and dries quickly — contains pollen, bits of leaves, grasses, and gas bubbles that provide a clear picture of the climate at the time.”
To refine their technique for analyzing urine, Chase said his team would identify a “good layer of solid urine" and then they would dig out samples and remove them from the hyrax nest. One nest in South Africa was found to have a urine layer about 55,000 years old, according to the scientists.
The team, which is based in South Africa, showed through their analysis that their region's climate has been sharply affected by climate forces originating in places as far away as the Arctic and Antarctic.
"There were several events not long after the end of the last Ice Age when there were dramatic drops in temperature in the Arctic,” Chase said. “These were due to great lakes of melted ice water bursting into the ocean.”
"They had a huge local impact in northern Europe but we did not know how the rest of the planet was affected,” he added. “Thanks to rock hyrax urine from the period, we have an answer. There was significant cooling in South Africa, and presumably the rest of the planet, at the time."
Chase´s team presented their findings at the annual meeting of the American Association for the Advancement of Science in Boston. They noted that their findings could have considerable practical implications, including influencing the carbon emission debate.
"The aim of these studies -- including our work on hyraxes -- is to create a very accurate timeline of past climate events so we can understand what is causing them," said Chase. "Some researchers use ice cores. We just happen to use urine."
Another U.K. speaker at the annual conference was Siwan Davies of Swansea University, who analyzed traces of volcanic dust in Greenland as a different way of understanding the historical fluctuations in the Arctic climate.
"Either the oceans are driving these changes or it is the atmosphere,” Davies said. “We need to find out which. To do this, we can study past changes in the atmosphere by analyzing ice cores which contain trapped bubbles of air and we can study ocean changes by analyzing mud cores from the seabed. Then we can compare them."