permaculture

[Lawrence London <lfljvenaura@gmail.com>]

What about Earth’s Microbiome? | Guest Blog, Scientific American Blog
Network
http://blogs.scientificamerican.com/guest-blog/2015/04/22/what-about-earths-microbiome/

Biological soil crust in Arches National Park, Utah. Biological soil crusts
are composed of oxygen-producing cyanobacteria, green algae, brown algae,
fungi, lichens and/or mosses. (Photo: Neal Herbert/National Park
Service/Flickr)

The latest temperature readings
<http://www.cnn.com/2015/04/01/travel/feat-antarctica-highest-temperature-ever-recorded/>
from Antarctica are giving the world pause, along with the finding that 70
percent of the western Antarctic ice shelf has melted. As Earth day
approaches, discussions around climate change tend to focus on rising
temperatures and sea levels, stronger storms and disruption of agriculture.
But one key player has been missing from this conversation: earth’s
microbes.

We keep seeing news items
<http://www.huffingtonpost.com/dr-raphael-kellman/the-microbiome-diet-evolv_2_b_6436122.html>
related to the human microbiome. That is, the trillions of microorganisms
living in our gut and on our bodies that are essential to our health and
wellbeing, but which are threatened by modern life. Our planet also has a
microbiome, a quadrillion quadrillion microorganisms
<http://www.nature.com/news/there-are-fewer-microbes-out-there-than-you-think-1.11275>
living in Earth’s crust and waterways, which is analogous in terms of
keeping our planet healthy—and it is similarly threatened by human activity.

These microorganisms created just the right conditions on the planet to
support higher forms of life, and eventually humans. Early planet Earth had
zero oxygen and 98 percent carbon dioxide. Our breathable air came about
because microbes invented photosynthesis almost four billion years ago,
which ate up most of the carbon dioxide and led to the production of
oxygen. By the time humans came on the scene, Earth’s atmosphere had 21
percent oxygen and 0.03 percent carbon dioxide.

Photosynthetic cyanobacteria (blue-green algae) under a microscope.
(Californai Environmental Protection Agency)

Without microbial development of photosynthesis, Earth would be nearly as
hot as Venus, and airless. Even today, though we usually think of plants as
responsible for photosynthesis, about 50 percent of global photosynthesis
is still carried out microbially, primarily in the oceans.

Most of us didn’t learn this in school biology. Maybe we put together one
of those 24 hour timelines <https://www.youtube.com/watch?v=H2_6cqa2cP4>,
beginning with the Big Bang and ending with humans. Science education often
glosses over the role of microorganisms in making life as we know it on
Earth possible, but we would not be here without millennia of
microbially-driven changes.

Yet human creativity and ingenuity in modifying the world around us has
imposed changes in an exceptionally short period of time. We have wrested
control from the microbes.

It took Earth’s microbiome 4 billion years to slowly turn the carbon
dioxide-oxygen ratio around; in the last 150 years, humans have increased
the amount of carbon dioxide in the atmosphere, from 0.03 to 0.04 perecent.
This change has happened 2,700 times faster than what occurred in the
previous 4 billion years.

The scientific community and others concerned are wondering how our planet
will respond to this change. But how will Earth’s microbiome respond? After
all, microbes have no vested interest in the status quo. The best
conditions for some of these microbes may be very different from those that
favor human health and welfare.

Typical orangish acid mine drainage coming from the abandoned Pennsylvania
Mine in Colorado. The acid mine drainage from this mine contains high
levels of metals, in particular, cadmium and zinc. (Photo courtesy of
Timberley Roane, University of Colorado Denver)

A good example is the acid mine drainage
<http://www.miningfacts.org/Environment/What-is-acid-rock-drainage/> that
results from mining. When we dig past the top layer of soil and vegetation,
oxygen penetrates the sulfide-containing coal or metal rich ores beneath
the surface. This awakens and feeds dormant microbes that oxidize iron and
sulfur deposits that coexist with coal and metals. In the process, the
microbes make acid, which leaches into the soil and ultimately the
waterways.

Normally, these microbes are small in number, and they are protected from
oxygen by topsoil and vegetation. Mining strips that away, allowing the
acid-producing microbes to thrive and bloom. Acid mine drainage has
threatened over 12,000 miles
<https://mail.google.com/mail/u/2/?pli=1#14c8cbf4c166c337_14c803624c7a2dbb_Legacy>
of streams and waterways in the United States alone. Around $1 million is
spent per day treating
<https://mail.google.com/mail/u/2/?pli=1#14c8cbf4c166c337_14c803624c7a2dbb_Legacy>it.
Once this process has started, it is very difficult to stop, and treatment
must go on in perpetuity.

Everything we do, from mining to burning of fossil fuels to large-scale
agriculture changes Earth’s microbiome. And scientists barely understand
how we are currently affecting it. We don’t know, for instance, how
microbial changes will impact our ability to grow plants and livestock
<http://www.usda.gov/oce/climate_change/effects_2012/CC%20and%20Agriculture%20Report%20%2802-04-2013%29b.pdf>—i.e.,
the food we eat. We don’t know how a warming climate will change patterns
of survival of microbes that cause infectious disease
<http://www.who.int/globalchange/environment/en/chapter6.pdf>. We are just
beginning to realize that extensive warming of permafrost soils may release
a treasure trove of heretofore frozen food for microbes, increasing carbon
dioxide emissions and climate warming to even greater rates than currently
exist. Understanding Earth’s microbiome is a challenge that rivals going to
the moon or developing cures for cancer.

Stordalen Mire, in Arctic Sweden, an area under intense study for
permafrost collapse. One collapse edge is seen bisecting the image, where
permafrost thaw is causing the ground to collapse into a wet boggy feature
all along the collapse front. In places, the access boardwalk is sinking
into recently-formed wet areas due to thaw. This change into wetland causes
a marked change in greenhouse gas emissions, which much more of the potent
greenhouse gas methane being released for each square meter of land thawed.
(Photo courtesy Scott Saleska, University of Arizona)

Until recently, the U.S. has led such challenges. But funding has fallen
flat
<http://www.slate.com/blogs/weigel/2014/05/07/the_first_bill_is_terrible_for_american_science_and_declining_research_funds.html>
for our research agencies, including the National Institutes of Health
<http://www.aaas.org/sites/default/files/NIHBud_1.jpg> and the National
Science Foundation <http://www.aaas.org/sites/default/files/NSF_0.jpg>.
Continuing this trend, the House Budget Committee recently voted
<http://www.huffingtonpost.com/2015/03/19/nih-funding-_n_6901932.html>
against an amendment to add $51 billion in funding to the National
Institutes of Health over the next decade. This vote demonstrates a
shortsighted view of the importance of the science research effort.

As our grandmothers probably told us, an ounce of prevention is worth a
pound of cure. We need to take up the gauntlet once again and renew our
investment in science and research to meet the challenges posed by climate
change, beginning with understanding Earth’s microbiome.
 *About the Author:* Raina M. Maier
<https://swes.cals.arizona.edu/people/faculty/raina-m-maier> is a Professor
of Environmental Microbiology in the Department of Soil, Water and
Environmental Science at the University of Arizona. Her research focuses on
understanding how we can exploit bacteria and their activities to benefit
human health and the environment. She serves as the Director of two
programs at the University of Arizona: the Superfund Research Program and
the Center for Environmentally Sustainable Mining. Maier is also a Public
Voices Fellow with The OpEd Project <http://www.theopedproject.org/>.