Letters from the West

Climate report details changes in Idaho, Northwest

The Obama Administration’s release of the third U.S. National Climate Assessment tells what Idahoans already know: winters are getting warmer, the runoff is coming sooner and we are seeing increased wildfires because of our increasingly hot, dry summers.

The report, written by many of the nation’s top climate scientists and peer reviewed by many more, shows how climate change already has affected both the built and natural landscape. And it predicts even changes more over the next 50 years.

Among the findings for the Pacific Northwest:

• “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 sea level rise, erosion, inundation, threats to infrastructure and habitat, and increasing ocean acidity collectively pose a major threat to the region.

• The combined impacts of increasing wildfire, insect outbreaks, and tree diseases are already causing widespread tree die-off and are virtually certain to cause additional forest mortality by the 2040s and long-term transformation of forest landscapes. Under higher-emissions scenarios, extensive conversion of subalpine forests to other forest types is projected by the 2080s.

• While the agriculture sector’s technical ability to adapt to changing conditions can offset some adverse impacts of a changing climate, there remain critical concerns for agriculture with respect to costs of adaptation, development of more climate resilient technologies and management, and development of more climate resilient technologies and management, and availability and timing of water. ” (NCA Ch. 21: Northwest)

As for Idaho:

• Climate: “Temperatures increased across the region from 1895 to 2011, with a regionally averaged warming of about 1.3 degrees. While precipitation has generally increased, trends are small as compared to natural variability.” (NCA Ch. 21: Northwest)

• Fisheries and freshwater species: “Region-wide summer temperature increases and, in certain basins, increased river flooding and winter flows 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, especially for spring/summer chinook and sockeye in the interior Columbia and Snake River basins.” (NCA Ch. 21: Northwest)

• Water: “Hydrologic response to climate change will depend upon the dominant form of precipitation in a particular watershed, as well as other local characteristics including elevation, aspect, geology, vegetation, and changing land use. The largest responses are expected to occur in basins with significant snow accumulation, where warming increases winter flows and advances the timing of spring melt. By 2050, snowmelt is projected to shift three to four weeks earlier than the 20th century average, and summer flows are projected to be substantially lower, even for an emissions scenario that assumes substantial emissions reductions.” (NCA Ch. 21: Northwest)

• Forests: “Climate change will alter Northwest forests by increasing wildfire risk and insect and tree disease outbreaks, and by forcing longer-term shifts in forest types and species. Many impacts will be driven by water deficits, which increase tree stress and mortality, tree vulnerability to insects, and fuel flammability. The cumulative effects of disturbance – and possibly interactions between insects and fires – will cause the greatest changes in Northwest forests.” (NCA Ch. 21: Northwest)

• Agriculture: “Projected warming will reduce the availability of irrigation water in snowmelt-fed basins and increase the probability of heat stress to field crops and tree fruit. Some crops will benefit from a longer growing season and/or higher atmospheric carbon dioxide, at least for a few decades. Longer-term consequences are less certain. Changes in plant diseases, pests, and weeds present additional potential risks.” (NCA Ch. 21: Northwest)

• Adaptation: “Agriculture is perhaps best positioned to adapt to climate trends without explicit planning and policy, because it already responds to annual climate variations and exploits a wide range of existing climates across the landscape. Some projected changes in climate, including warmer winters, longer annual frost-free periods, and relatively unchanged or increased winter precipitation, could be beneficial to some agriculture systems. Nonetheless, rapid climate change could present difficulties.” (NCA Ch. 21: Northwest)

• Tribes: “Observed and future impacts from climate change threaten native peoples’ access to traditional foods such as fish, game, and wild and cultivated crops, which have provided sustenance as well as cultural, economic, medicinal, and community health for generations. Native communities’ vulnerabilities and limited capacity to adapt to water-related challenges are exacerbated by historical and contemporary government policies and poor socioeconomic conditions.” (NCA Ch. 12: Indigenous Peoples)

So what does the Obama administration say we should do about this?

Land-use planning: to protect infrastructure and ecosystems; regulations related to the design and construction of buildings, road, and bridges; and preparation for emergency response and recovery.

Cut carbon: In 2012, power plants and major industrial facilities in Idaho emitted more than 3 million metric tons of carbon pollution — that’s equal to the yearly pollution from more than 600,000 cars.