Options for Improving Climate Modeling to Assist Water Utility ...

Water Utility Climate Alliance White Paper
Options for Improving Climate Modeling to Assist Water Utility Planning for Climate Change
Preface
Since its creation in mid-2007, a key priority of the Water Utility Climate Alliance (WUCA) has
been federally-supported climate research, both the nature and focus of the research, as well as
its accessibility. This priority stems from our need to better understand the potential impacts on
the water systems we manage and our commitment to develop adaptation options that address
those impacts. We believe that climate research that reflects the needs of, and is accessible to, the
water sector is crucial to furthering our understanding of climate change and in informing the
development of appropriate adaptation options. As a result, WUCA has actively tried to advise
the federal climate research program to meet these needs in as collaborative a manner as
possible. We have commented on research plans of the U.S. Climate Change Science Program,
we have testified on legislation regarding the creation of a National Climate Service and we have
pursued other opportunities to affect federal action on climate research. Our latest effort, this
white paper on climate modeling and downscaling, reflects both a continuation and an evolution
of this activity.
This paper addresses a number of topics and in so doing, continues WUCA’s efforts to improve
our understanding of climate change. It explains how climate models work, describes how some
WUCA members have used climate models and downscaling to assess impacts on their systems
and develop adaptation options, and makes seven initial recommendations for how climate
modeling and downscaling techniques can be improved so that these tools and techniques can be
more useful for the water sector. However, a key finding of the report is that for the next few
years, maybe a decade or so, significant uncertainties will remain about how climate will change
at the scale utilities make decisions. In the long run, we may be able to reduce those
uncertainties. In the short run, it is possible with existing technology, such as models and
observations, to more completely understand the range of potential changes in climate. More
importantly, the white paper represents what we hope is a catalyst for a continued dialogue
between water utilities, the climate modeling and research community and federal agencies on
how we can collaborate to better address the climate adaptation needs of the water sector.
WUCA and the authors of the white paper unveiled the final draft of this white paper in
September 2009 at a climate modeling workshop held at the Aspen Global Change Institute in
Aspen, CO. Attendees included WUCA members, global climate modelers and researchers,
experts in downscaling, and federal agency staff. Over the course of the workshop WUCA
members learned more about modeling efforts underway and how our recommendations are or
are not being addressed through these programs, while the climate modelers learned how the
water sector is using climate models to understand the implications of climate change. Members
of the modeling community that reviewed this report have agreed that it is one of the best
summaries of climate modeling for non-modelers. As a result of this interaction, we view this