Mini worlds may simulate climate change, extraterrestrial and ancient earth’s atmospheres
(From left to right) John VandenBrooks and Jon Harrison
“Global climate change” – words on the lips of senators, students, housewives and school children. The “new’ phenomenon is featured in headlines and theater marquees and accepted by the scientific community. However, change in Earth’s atmosphere is not new. Big swings in atmospheric oxygen range from 30 percent to 13 percent in Earth’s ancient past, to today’s 21 percent. So why the current concern? Such past changes have also been linked to profound outcomes, such as gigantism in insects in the Permian age and catastrophic extinctions of species in the Triassic period – the evolution of all we see around us.
It gives one pause when considering our own future. What will the shift in our present day greenhouse gases and UV radiation ultimately mean? A pair of scientists at Arizona State University think the answers might be found through the creation of mini-worlds.
Professor Jon Harrison and John VandenBrooks, researchers in ASU’s School of Life Sciences, are leading the effort to establish a Variable Atmosphere Laboratory (VAL) on ASU’s Polytechnic campus that would support 50-70 mini-worlds and enable the small scale creation of atmospheric conditions found from Mount Everest to Mars.
“In each of the VAL’s modules we could manipulate a wide range of atmospheres, creating conditions that might exist in the future or recreating those of ancient Earth,” notes VandenBrooks, a postdoctoral fellow with Harrison’s group. “By having the capacity to manipulate trace gases like ozone, temperature, humidity, UV radiation, barometric pressure and carbon dioxide, we can examine the effects of inner-city pollution or even simulate extraterrestrial atmospheres.”
“Biosphere 2 raised the awareness of environmental scientists of all types to the potential benefits of experimental simulation of alternative climate conditions,” says Jonathan Fink, director of the Global Institute of Sustainability (GIOS) and strong proponent for the creation of the laboratory.
The Biosphere 2 project, completed in 1991 in Oracle, Arizona, was designed to be a self-contained, isolated ecosystem to help to determine the conditions necessary for space travel. Harrison is quick to point out that “the Biosphere 2 and VAL are significantly different.” Biosphere 2 did not have the capacity to determine cause and effect in relationships. Harrison explains, “that requires the ability to manipulate variable and replicate experiments, as our Variable Atmosphere Laboratory does.”
“With society performing a dangerous and uncontrolled climate experiment by altering the composition of our atmosphere, building a Variable Atmosphere Laboratory would allow scientists to safely investigate the consequences of increasing carbon dioxide, methane, and other gases, and add important complementary strengths to our programs in sustainability, Earth and space exploration, and environmental fluid dynamics,” Fink adds.
A workshop held at ASU’s Center for Social Dynamics and Complexity last month, with support by the National Science Foundation (NSF), and GIOS, brought together a diverse group of scientific experts from the College of Liberal Arts and Sciences and abroad, including program officers from NSF and National Institutes of Health (NIH), to review preliminary plans for the laboratory, and discuss the types of questions such a laboratory could uniquely address.
For example, workshop attendee, and curator of paleontology for the Denver Museum of Nature and Science, Ian Miller’s asks how atmospheric conditions may have affected evolution in ancient plants, like ginkgos. Physiologist Ray Huey from the University of Washington investigates how oxygen and altitude may have imposed limits to the movement of animals across mountain ranges and led to increased endemism in the Triassic. By contrast, public health concerns motivate workshop participant James Lee. A researcher with the Mayo Clinic in Scottsdale, Lee questions the extent to which increases in trace gases, such as ozone and carbon monoxide, are responsible for sky-rocketing cases of asthma.
This range of perspectives is integral to the design and development of the laboratory, but how can one facility provide insights across such wide range of fields?
“What separates VAL from something like a simple environmental chamber is not only size and scale, but the scope of what it can control,” notes VandenBrooks. “Such a large scale facility can examine geological structures and soils, man-made nanoparticles, and a range of biological organisms, even small trees, terrestrial and aquatic communities, allowing it to address key questions in astrobiology, paleontology, medicine and evolution.”
Harrison says they both envision the Variable Atmosphere Laboratory as a national facility that would “provide the United States with the world’s premier tool for experimental, replicatable study of the effects of different atmospheres on biological and geological processes.”
“The United States is in the process of creating NEON, a national facility for documenting the magnitude and ecological effects of climate change. VAL would be a complementary tool to test for cause-and-effect relationships,” Harrison adds.
Preliminary plans have been drawn up by architects and engineers from the design firm CH2M Hill partnered with IDC Architects, with funds from ASU’s School of Life Sciences, School of Earth and Space Exploration, and Global Institute of Sustainability. The facility is projected to cost $80 million to $100 million to build.
The inspiration for the Variable Atmosphere Laboratory grew out of needs and questions intrinsic in VandenBrooks and Harrison own research studies. Awarded a $500,000 grant from NSF in February, the two are set to investigate the effects of atmospheric oxygen on the development and evolution of insects, in particular the apparent correlation between the presence of high oxygen levels in ancient earth and gigantism in insects in the Carboniferous and Permian periods.
In lieu of an atmospheric facility, the two will focus on manipulation of one gas, oxygen, examining its effect on physiology and development in two modern insects, cockroaches and dragonflies, whose ancient ancestors developed and evolved during times of oxygen fluctuation.
Harrison’s previous research has shown that high oxygen environments alter the size of multiple modern insects, including fruit flies and caterpillars, but no studies to date have examined the effect of oxygen on insects closely related to those who lived in the Paleozoic. In addition, the two scientists will perform the first quantitative test of whether the size of insects in the late Paleozoic actually did correlate with atmospheric oxygen. To do this, they will measure the body and wing size of fossil insects from six museums around the world.
A final goal of the project is to develop a method to estimate atmospheric oxygen level from fossils, as can now be done from the relationship between atmospheric carbon dioxide and fossil plant stomate density. Harrison’s research has shown that insect tracheal dimensions (these are the tubes insects breathe with) vary with atmospheric oxygen level. They hope to measure the dimensions of tracheae inside insects preserved in amber, using X-ray synchotron imaging.
If they are successful, it would represent a major advance in geology and climate science, Harrison and VandenBrooks believe.
VandenBrooks’ interest in the overlap between different disciplines started early in his career. Switching from an undergraduate degree at University of Michigan in chemistry, to pursue his doctoral degree at Yale in geology, geochemistry and paleontology, he says what has fascinated him is how things at a small scale can quickly scale up to affect things on a larger scale.
“In chemistry, you look at processes that happen on a tiny level and at such fast timescales. In geology, you need to wrap your head around things that can take a billion years to happen,” VandenBrooks says. “It’s amazing that there is some interaction between a billion year and the femtosecond timescale. It’s really amazing to try to meld these different perspectives together, and this is exactly what we hope to do with the creation of VAL.”
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