The new findings, published today in the journal Nature Communications, show that alpine tundra in Colorado’s Front Range emits more CO2 than it captures annually, potentially creating a feedback loop that could increase climate warming and lead to even more CO2 emissions in the future.

A similar phenomenon exists in the Arctic, where research in recent decades has shown that melting permafrost is unearthing long-frozen tundra soil and releasing CO2 reserves that had been buried for centuries.

“We wondered if the same thing could be happening in alpine terrain,” said John Knowles, lead author of the new study and a former doctoral student in ���Ҵ�ý�ƽ������ Department of Geography and a researcher at the . “This study is a strong indication that that is indeed the case.”

Forests have long been considered vital carbon ‘sinks,’ sequestering more carbon than they produce and helping to mitigate global CO2 levels. As part of the Earth’s carbon cycle, trees and other vegetation absorb CO2 via photosynthesis while microbes (which decompose soil nutrients and organic material) emit it back to the atmosphere via respiration, just as humans release CO2 with every breath. 

Melting permafrost, however, changes that equation. As previously frozen tundra soil thaws and becomes exposed for the first time in years, its nutrients become freshly available for microbes to consume. And unlike plants, which go dormant in winter, microscopic organisms can feast all year long if environmental conditions are right.

To study this effect in alpine conditions, researchers measured the surface-to-air CO2 transfer over seven consecutive years (2008-2014) at the  site in Colorado, a high-altitude research project funded by the National Science Foundation that has been in continuous operation for over 35 years. The team also collected samples of soil CO2 and used radiocarbon dating to estimate how long the carbon forming that CO2 had been present in the landscape.

The study showed, somewhat surprisingly, that barren, wind-scoured tundra landscapes above 11,000 feet emitted more CO2 than they captured each year, and that a fraction of that CO2 was relatively old during the winter, the first such finding of its kind in temperate latitudes. The findings suggest higher-than-expected year-round microbial activity, even in the absence of a deep insulating snowpack.

“Microbes need it to be not too cold and not too dry, they need liquid water,” said Knowles, now a researcher at the University of Arizona. “The surprise here is that we show winter microbial activity persisting in permafrost areas that don’t collect much insulating snowpack due to wind stripping it away.”

While the alpine tundra’s net CO2 contributions are small compared to a forest’s sequestration capability, the newly-documented effect may act as something of a counterweight, hampering atmospheric CO2 reductions from mountain ecosystems in general. The findings will need to be factored in to future projections of global warming, Knowles said.

“Until now, little was known about how alpine tundra behaved with regard to this balance, and especially how it could continue emitting CO2 year after year” Knowles said. “But now, we have evidence that climate change or another disturbance may be liberating decades-to-centuries-old carbon from this landscape.”

Additional co-authors of the study include Peter Blanken of ���Ҵ�ý�ƽ������ Department of Geography; Mark Williams of ���Ҵ�ý�ƽ������ and INSTAAR; and Corey Lawrence of the U.S. Geological Survey. The National Science Foundation provided funding for the research.

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This course describes the basic components of the climate system: the atmosphere, ocean, cyrosphere, and lithosphere. We will investigate the basic physical processes that determine climate and the link between the components of the climate system. Emphasis is placed on the hydrologic cycle and its role in climate, climate stability, and global change. The theme throughout this course will be an examination of the importance of climate as one of the major forcing functions in environmental change. Both human-induced and natural climate variability will be covered.

See the  for specifics, recommendations, and prerequisites.

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When Peter Blanken flew to Paris for the 2015 United Nations Climate Change Conference in December, he had somewhat low expectations. “Going into it, I felt pessimistic,” says Blanken, associate professor of geography at the University of Colorado Boulder, who was one of 10 official observers selected by the Association of American Geographers.

And who could fault his pessimism? Global atmospheric concentrations of carbon dioxide surpassed 400 parts per million for the first time in 800,000 years in 2015, while experts were warning a decade ago that 350 ppm might be a point of no return. In the United States, widespread skepticism about climate change persists despite an overwhelming scientific consensus that human activity is causing a steady rise in global mean temperatures.

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Peter Blanken and Christopher Spence of Environment Canada say information they are gathering about the Great Lakes this winter bodes well for water levels this summer, and a better understanding of water loss on the lakes could yield helpful forecasting for marinas and the shipping industry.

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Miles Offshore, Are Lighthouse Cribs Beginning to Rot from Air Exposure? Professor Peter Blanken's research on the Great Lakes takes a new look at Winter Evaporation as Key Process in Water Levels. This research is featured in an article from the July 4, 2013 The St. Ignace News.

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The College Scholars program is funded through the generosity of donors to the College of Arts & Sciences. The award enables enables tenured faculty to pursue full time research/creative scholarly activities for one semester. Peter is 1 of 10 recipients of the prestigious award. He will use the award to support his research on "New Approaches to Explore Negative Feedbacks in the Climate System".

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The Department of Geography received an Assett (Arts and Sciences Support of Education Through Technology) award relating to the use of technology primarily for teaching and learning. The funding will be used to implement the use of mobile web and applications into many of the Geography course labs and recitations within the next year. PhD candidate, Preston Cumming submitted the funding proposal with support from department chair, Peter Blanken.

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