This
page provides links to several
datasets that were generated for and presented in Dobrowski and Parks, 2016 (citation below). These datasets represent metrics of climate change
exposure
and are based on the premise that unique climates are shifting in
response to
climate change. The rate of these climatic shifts is termed climate
change
velocity, which is often invoked as a metric of climate change
exposure.
The
products provided here measure
the distance (and therefore the velocity) between each pixel and its
future
climate analog in a different manner compared to previous approaches.
Notably,
the distance is not based on a straight line (i.e. Euclidean distance)
between
the source and destination pixel, but is instead based on a trajectory
that that
minimizes exposure to dissimilar climates. The trajectory between each
source
and destination pixel was delineated using least-cost methods that
utilized a
resistance surface that penalized dissimilar climates. The distance of
this
trajectory, or path, is termed the minimum exposure distance (MED).
Similarly,
the velocity is the length of this trajectory divided by the elapsed
time
between the reference and future time period and is termed velocityMED.
By definition, the MED-based velocity is always greater than or equal
to
ED-based velocity.
Figure 1. Climate trajectories and minimum cumulative exposure (MCE).
Figure 2. Climate velocity for North America for the interval 1995 to 2085
This
dataset also includes an
additional measure of climate change exposure that is complementary to
velocity-based metrics. This newly developed metric is termed minimum
cumulative exposure (MCE) and quantifies the exposure to dissimilar
climates
(in °C) along each trajectory. That is, each source and destination
pixel has
an associated trajectory, or path, that was delineated by minimizing
exposure,
and MCE quantifies the exposure along those trajectories. Generally,
regions
with little topographic relief have little-to-no MCE because there is
no
climatic resistance to movement, whereas more topographically complex
regions
have higher MCE because intervening valleys and mountains between each
source
and destination pixel have more climatic resistance.
Figure 3. Minimum cumulative exposure (MCE).
Figure 4. Classification of velocity and minimum cumulative exposure (MCE).
Figure 5. Climate trajectories for Yellowstone National Park, USA.
In
total, there are five gridded products contained in the zipfile linked below:
1.
Minimum exposure distance (MED; km)
2.
MED-based climate velocity (velocityMED;
km/year)
3.
Minimum cumulative exposure (MCE; °C)
4.
ED-based velocity (velocityED; km/year)
5.
Ratio of MED:ED
The
reference climate is represented
my mean annual temperature for the years 1981-2010 and the future
climate is
represented by mean annual temperature for the years 2071-2100. Future
climate
is an ensemble of 15 CMIP5 GCMs and use the RCP 8.5 emissions scenario.
All
climate datasets were obtained from AdaptWest
(https://adaptwest.databasin.org/).
This
dataset has been prepared for
the AdaptWest project and was funded by the National Science Foundation
and the
USFS Rocky Mountain Research Station.
Data files
|
Download
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Documentation
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Word: ![]() |
Sample code and input data used in the analysis
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Zipfile: ![]() |
Output grids for MED, velocityMED, MCE, velocityED, and ratio of MED:ED
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Zipfile: ![]() |