By Lisa Micheli, PhD
Often when people
learn I work on climate change they ask me how I can avoid becoming depressed.
I don't get depressed because humanity has demonstrated over and over again its
capacity for change. But honestly sometimes I do get frightened looking at what
the next century and beyond may hold for our children and theirs, especially if
we do not take actions to stem the pace of climate change now. This year in
particular, when each new catastrophic headline points to the impact of a
weather extreme, it feels eerily like the climate models I've been staring at
since about 2007 are starting to unfold in our material world. And now concern
about how we will actually handle our local climate extremes is not limited
just to me and my in-the-know colleagues, but is one of the chief topics being
debated at cafés, gas stations and grocery stores throughout my neighborhood in
light of the California drought now fully upon us. (While last weekend’s storm
has brought some immediate relief, we are still in a drought!)
In science we know
that all models are wrong, but some models are useful. I estimate that back in
the early 90s I was approximately the last person let into an Earth Sciences
doctorate program without any computer programming experience. I lived through
a transition in my chosen field of hydrology from an emphasis on measuring the
planet to a fixation on modeling the planet. When I was at UC Berkeley I had
the honor of belonging to the Energy and Resources Group, probably one of our most prestigious
energy and climate think tanks. But at the time my interest was zeroed in on
urgent challenges in water resources. I spent my time in with the geomorphology
research group both in the field and on the computer researching how to restore
California's rivers, a problem we faced in the moment, not something projected
for the future by a computer model. I simply left the question of climate
change to my colleagues.
It took the extreme
heat waves of 2007 (over 115 degrees Fahrenheit in Sonoma) to steer my
attention towards the inevitability of climate trends, and in turn, the
necessity for conservation practitioners like myself to start to take climate
change seriously. I perceived this as an obligation particularly because we
were engaged in building habitat restoration projects that would take centuries
to mature and fulfill their promised potential. Soon after I helped to found
the North Bay Climate Adaptation Imitative which will be working with the County of Sonoma on a Climate Ready regional climate vulnerability analysis under
the auspices of the State Coastal Conservancy and Pepperwood this year.
Scientists know that
our climate system is complex enough that we cannot point to a single event and
say this was caused by greenhouse gas emissions, and by copping to that
we create fodder for a lot of debate in the media. But now there is increasing
certainty around climate trends that recent advances in computer
modeling can customize to local regions like our own, and now our weather
station measurements are increasingly confirming those modeled trends.
One of my roles at
Pepperwood is to facilitate scientific teams like the Terrestrial Biodiversity
Climate Change Collaborative (TBC3) which I co-chair with Prof. David Ackerly
of UC Berkeley. We just completed a two-year study thanks to the Gordon and Betty Moore Foundation. The
cornerstone of TBC3's 2013 products is a set of climate projections for the Bay
Area crafted by the USGS' Lorraine and Alan Flint in concert with geospatial
analyst extraordinaire Dr. Stuart Weiss of the Creekside Center for Earth
Observation. Under the expert guidance of IPCC scientists,
this team selected 18 climate futures that represent the full statistical
extent of the IPCC's global analyses. Then we “downscaled”
these projections to 18-acre "pixels" for the San Francisco Bay Area.
As a result, land and water managers in the Bay Area finally have climate
projections at a scale they can incorporate into their long-term planning
processes. (You can now access a subset
of the TBC3 climate futures data at bayarealands.org via the Explorer Tool's
new Climate Portfolio Report for your own region of interest.)
The trend for the Bay
Area we identified in our original 2012 publication was that despite the potential range in total quantities of
winter rainfall projected for the future, our watersheds are going to be prone
to becoming more arid. In other words, there is a risk of increasingly
short winter wet periods and increasingly extended dry periods, also known as
droughts, as in exactly what we are experiencing this year in Northern
California. One of the tools developed by Dr. Weiss to visualize the Flints' Basin Characterization Model
data set are water cycle diagrams that depict seasonal fluctuations in rainfall
and its products. Below is a graph of the average annual water cycle for
the Upper Sonoma Creek watershed, using historical data (1980-2009).
Upper Sonoma Creek - Average Annual Water Cycle (1980-2009) |
The total
height of the "wave" moving through each month of the season is
equivalent to the total rainfall received over that month. The area in light
green evaporates directly to the atmosphere or through plant respiration. The
area in dark green is the water that stored in the soils for plants to use. The
area in dark blue refills our underground groundwater basins. The area in light
blue is the water available to feed our streams and reservoirs. The area in red
that grows at the end of the summer season is the climatic “water deficit,” a
measure of drought stress.
Now below is the same
diagram representing the drought of 1975 to 1976 on Upper Sonoma Creek. As you
can see it is almost all light green and red – meaning that all the incoming
rainfall, which was very limited that year, was used up by plants with almost
no water left to recharge the groundwater or feed streams. And that is similar
to what is happening to our watersheds this year.
It's interesting to
me that those of us who wear water goggles all the time – i.e. we look
out at the world through the lens of water – probably considered us to be in
trouble at the end of last year's wet season, when despite experiencing flood
conditions in November, the absence of any further rain left us in a drought by
May. Now in May we didn't know what this winter would hold, but there's always
a chance of another dry year following a drought year, and when this happens
three years in a row the water managers consider this an emergency. Dr.
Weiss's preliminary analyses of the climate futures for the Bay Area suggests
that three-year droughts could be a more frequent event.
I was reassured to
have recently learned from a sociologist presenting at the Nature Conservancy's
annual science symposium that what I felt in my gut about people was true. That
is that while there can be relatively predictable divisions along political lines
regarding the theory of climate change, there is in fact almost unanimous
bi-partisan support for ensuring that communities in the US are prepared to
deal with natural resource crises such as this year's drought. We see this as
our community comes together to face this challenge, to support the ranchers
who cannot feed their cattle because there's no water to make the grass grow,
to support the water districts in their need to stretch a stressed supply.
However that is one of the mysteries to me about our social response – why are
we just starting to talk about water conservation measures now, when it was
clear last May we were already facing risks to our water security?
Thanks to Dr. David
Ackerly's TBC3 long-term forest monitoring project at Pepperwood, we will have data
to evaluate hypotheses about how this drought is impacting our forests.
Informed observers say things like "the forest looks stressed to me,"
or "I think I am seeing more brown tipped leaves," or "I think
species X is having a really hard time." I now have some rigorous
measurements in place to test these emerging hypotheses. Thanks to Dr. Ackerly and his laboratory at Berkeley's
Department of Integrative Biology, there are 50 sites at Pepperwood where every
single plant has been identified and measured. Now when we conduct our repeat
measurements we will have actual data capable of showing the impact of the
drought on plant composition and survival. This kind of scientific research
will be absolutely critical to better understanding how our natural resources
will respond to increasing climate and water stresses.
What the TBC3 project
at Pepperwood does is provide a high resolution portal on local changes in the
context of global climate science. Fran Ulmer, chair of the US Arctic Research Commission recently shared upon release of the Arctic Report Card 2013 the following
perspective: The Arctic is not like Las Vegas: whathappens in the Arctic does not stay in the Arctic.
So while
my personal mission is one of equipping our communities to be resilient in the
face of climate change based on real-time local data, the magnitude of the
challenge we face will be directly proportional to our ability to steer our
energy consumption patterns away from carbon-based fuels. Another catchphrase which
has been in the forefront of my mind is the following. There are known alternatives
to fossil fuels. There are no known alternatives to water.