Northwest could feel global warming early
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January 26, 2013 |
“Evidence for climate change abounds, from the
top of the atmosphere to the depths of the
oceans. This evidence has been compiled by
scientists and engineers from around the world,
using satellites, weather balloons,
thermometers, buoys, and other observing
systems,” according to a new report prepared for
the U.S. government with the contributions of
more than 1,000 individuals.
“The sum total of this evidence tells an
unambiguous story: the planet is warming,” the
new “National Climate Assessment” says. Much of
that climate change is driven by humans with the
ever-increasing emission of gases into the
atmosphere, and could only likely slowed by a
reduction in such emissions, the report says.
Climate change, as projected by scientists,
means significant changes for human life and the
environmental processes that support it,
according to a new report.
The Pacific Northwest, with its heavy reliance
on the timing and quantity of water deliveries
from Mother Nature, figures to be affected
considerably by a warming climate. Some of the
key messages noted by authors of the Northwest
section of the report are that:
-- Changes in the timing of streamflow related
to changing snowmelt are already observed and
will continue, reducing the supply of water for
many competing demands and causing far-reaching
ecological and socioeconomic consequences.
-- In the coastal zone, the effects of erosion,
inundation, threats to infrastructure and
habitat, and increasing ocean acidity
collectively pose a major threat to the region.
-- The combined impact of increasing wildfire,
insect outbreaks, and diseases is virtually
certain to cause additional forest mortality by
the 2040s and long-term transformation of forest
landscapes. Almost complete loss of subalpine
forests is expected by the 2080s.
-- While the agriculture sector’s technical
ability to adapt to changing conditions can
offset some of the adverse impacts of a changing
climate, there remain critical sector-specific
concerns with respect to costs of adaptation,
development of more climate resilient
technologies and management, and availability
and timing of water.
The Northwest section was authored by experts
from Oregon State University and the University
of Washington, as well as the University of
Idaho, the Idaho Department of Water Resources,
the National Wildlife Federation and the
Cascadia Consulting Group.
“Reservoir systems have multiple objectives,
including irrigation, municipal and industrial
use, hydropower production, flood control, and
preserving fish habitat. Modeling studies
indicate, with near 100 percent likelihood, that
reductions in summer flow will occur by 2050 in
basins with significant snowmelt,” according to
the report’s Northwest chapter. The report cites
numerous studies.
“Combined with summer increases in heat-driven
electric power demand for cooling and
evaporative demand from crops and forests, these
reduced flows will require tradeoffs among
objectives of the whole system of reservoirs.
“For example, reductions in hydropower
production of as much as 20 percent by the 2080s
could be required to preserve in-stream flow
targets for fish in the Columbia River basin,”
the report says. “Springtime irrigation
diversions increased between 1970 and 2007 in
the Snake River basin, as earlier snowmelt led
to reduced spring soil moisture. In the absence
of adaptation, annual hydropower production is
much more likely to decrease than to increase;
economic impacts of hydropower changes could be
substantial, on the order of hundreds of
millions of dollars per year.
“Several aspects of hydrologic change, such as
increased flooding in mixed rain-snow basins,
region-wide increased winter flows and summer
temperatures, and decreased summer flows, will
threaten many freshwater species, particularly
salmon, steelhead, and trout. Rising
temperatures will increase disease and/or
mortality in several iconic salmon species,
including spring/summer chinook and sockeye,
especially in the interior Columbia and Snake
River basins,” the report says, although some
streams are less sensitive to warming because of
the temperature buffering provided by snowmelt
and groundwater. By the 2080s, suitable habitat
for the four trout species of the interior
western U.S. is projected to decline 47 percent
on average compared to 1978-97.”
The National Climate Assessment was prepared for
a committee of independent advisers to the U.S.
government. The 400-page document is a synthesis
of scientists’ current understanding of climate
change and its potential impacts in the United
States.
The Global Change Research Act of 1990 calls for
an NCA to be produced at least every four years;
the last came out in 2009.
The draft NCA is a scientific document -- not a
policy document -- and does not make
recommendations regarding actions that might be
taken in response to climate change, according
to a blog posted on the White House web site by
John P. Holdren, assistant to the president and
director of the White House Office of Science
and Technology Policy, and Jane Lubchenco,
administrator of the National Oceanic and
Atmospheric Administration
“Today is the first time the government has been
presented with this draft and the administration
will be one of a number of entities that will
begin the process of reviewing it. When
completed about a year from now, however – after
considerable inputs from the public and expert
reviewers – it will represent the most thorough,
rigorous, and transparent assessment ever of
climate change and its U.S. impacts.”
The new NCA draft version reflects the efforts
of individuals from the public and private
sectors and academia who have been compiling
data since 2010.
A public review period started January 14.
Comments will be accepted through April 12.
The document will also be reviewed by the
National Academies.
Ultimately, towards the end of this year, a
final NCA will be presented to the United States
Global Change Research Program, which
coordinates global-change research activities
across the federal government. USGCRP will use
the assessment to help pinpoint knowledge gaps
and develop research priorities.
The blog stresses that the NCA is expected to be
used widely by public and private stakeholders
who need information about climate change in
order to thrive – from farmers deciding which
crops to grow, to city planners deciding the
diameter of new storm sewers they are replacing,
to electric utilities and regulators pondering
how to protect the power grid.
To maximize its practical usefulness, the draft
document breaks down the impacts of climate
change across eight regions of the United States
and more than a dozen sectors of the U.S.
economy and society, including: energy,
transportation, agriculture, health, urban
infrastructure, coastal zone development, and
water resources.
While the specific findings of the draft NCA are
still subject to revision in response to inputs
from the public, the National Academies, and the
13 federal departments and agencies that make up
the USGCRP, the document released Jan. 11 sets a
new standard of scientific integrity, user
relevance, and stakeholder inclusiveness, the
Holdren-Lubchenco blog says.
It was developed with input from more than 240
contributing authors under the leadership of 60
independent expert advisors. More than 1,000
volunteers across the nation helped build it
from the ground-up by organizing regional
workshops and contributing technical reports.
In a parallel effort, USGCRP recently launched “NCAnet,”
a growing network of more than 60 stakeholder
organizations committed to engaging broad and
diverse audiences on the topic.
To access the draft National Climate Assessment,
please visit
www.ncadac.globalchange.gov.
For detailed background information about sea
level rise and climate trends, please visit:
http://scenarios.globalchange.gov.
For detailed information about coastal changes,
please visit:
http://www.globalchange.gov/what-we-do/assessment/nca-activities/available-technical-inputs. |
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