Downscaling IPCC land use scenarios for global change adaptation planning in mountains
Authors
Andrew J. Hansen, David Theobald, Katrina Mullan, Scott Powell
Funding
National Aeronautics and Space Administration (NASA)
Abstract
Mountain landscapes are undergoing rapid rates of climate and land use change and
are
sensitive to these changes. The resulting vulnerability is of concern because of the
critical role
mountain areas play in the provisioning of ecosystem services and in global conservation
strategies. Thus, evaluation of plausible future scenarios of global change is critical
in mountains
to explore the potential consequences of different response options. The Intergovernmental
Panel
on Climate Change (IPCC) uses scenario development as its major vehicle for helping
people to
visualize potential future conditions, their consequences for humans and ecosystems,
and
adaptation options. Downscaling IPCC climate projections to spatial scales relevant
for
policy has been widely employed. Equally important is downscaling IPCC socioeconomic
scenarios and resulting land use change. The first effort to do so for the U.S. by
Co-I.
Theobald and colleagues resulted in projections untenable for rural landscapes. We
found that
their projected rates of land cover and land use change (LCLUC) around national parks
were
dramatically lower than observed rates, suggesting errors in the downscaling of housing
demands in rural counties. A more recent effort to downscale IPCC scenarios for the
U.S. was
done by the U.S. Geological Survey (USGS). Their approach was to first define demand
for
land cover types for each scenario at the national scale, then refine demand down
to the level of
EPA Type III ecoregions, then spatially allocated types locally. While their classes
of
agriculture, forest harvest, and mining are highly relevant to rural mountain landscapes,
their
“developed” class does not adequately distinguish rural housing, the fastest increasing
land use
in these landscapes.
Our goal is to project LCLUC under IPCC scenarios across western mountain
landscapes and to apply the results to enhance vulnerability assessments of biodiversity
to
future global change. Our objectives are to: 1. Enhance USGS efforts to quantify LCLUC
in
landscape samples for the period 1973-2014 through innovative remote sensing applications;
2.
Test hypotheses on the relative and context-dependent influence on rural LCLUC of
proximity to
cities and markets, natural resources, natural amenities, and climate change; 3.Modify
the
SERGoM land use change model based on the results of the hypothesis testing and project
LCLUC under the IPCC scenarios; 4. Assess the influence of projected LCLUC on wildlands
and tree species habitat suitability.