The effects of climate change vary over both space and time, and in a country as large as the United States, these changes can be significant. We need consistent information about observed climate trends, projected climate changes and impacts at the watershed scale to support USACE climate change adaptation.
Regional climate impact assessments have been developed from a number of different sources for a variety of audiences. USACE requires regional assessments tailored to our specific missions to address issues of critical interest to USACE and its stakeholders. USACE will be developing regional climate change literature syntheses at the 2-digit hydrologic unit code (HUC 2) level, a watershed scale suited to the size of USACE Divisions. These regional syntheses will address issues of interest to USACE Civil Works business lines.
Until these regional syntheses are ready, USACE staff can consider regional climate impact assessments that have been developed from a number of different sources for a variety of audiences. These include the regional assessments prepared for the National Climate Assessment, assessments prepared by other Federal agencies, information developed for the USACE climate change adaptation pilot studies, and specifically-tailored information for certain watersheds. These assessments have been conducted under a number of programs and include:
Regional to Local Scale Adaptation Pilots
Pilots and Demonstrations Program, which provided support for Districts to tackle climate change issues within major river basins. A total of 15 projects were supported during fiscal years 2010 through 2012. These projects examined the impacts of sea level rise, and coastal and inland flooding on USACE dams and levees, ecosystem restoration features, and water supply across the nation. In addition, these projects allowed District and HQUSACE staff to engage local and regional stakeholders on the issues of climate change impacts and adaptation. Additional information on this program can be found on the climate change adaptation pilot studies web page.
Climate Change by Hydrologic Unit Code Project provides a detailed summary of the primary literature for major river basins in the United States, including Alaska and Hawaii. This effort complements Reclamations Climate Literature Synthesis product by addressing smaller geographic scales and by extending coverage to the entire country. This project is ongoing.
District-driven projects that benefit regional stakeholders have also been supported by the Responses to Climate Change Program. For example, the program supported USACE Albuquerque District participation in the Bureau of Reclamation-led Upper Rio Grande Impact Assessment, which examined current climate trends in and model projections of future climate in the Rio Grande Basin above Elephant Butte and the resulting impacts to the regional water supply. The full report is available online.
The Responses to Climate Change Program is also supporting USACE Albuquerque District participation in the Central New Mexico Climate Change Scenario Planning Project, a U.S. Department of Transportation project to develop planning scenarios that incorporate projected changes in land use, population, urbanization, and climate. This will allow local communities to better account for these factors when they plan future urban and suburban development, manufacturing facilities, and transportation and other infrastructure. This project is ongoing.
Regional Climate Change and Hydrology Literature Syntheses
USACE has begun releasing a series of 21 regional climate syntheses at the scale of 2-digit U.S. Geological Survey (USGS) Hydrologic Unit Codes (HUC) across the continental United States, Alaska, Hawaii, and Puerto Rico. Each of these regional reports summarizes observed and projected climate and hydrological patterns cited in reputable peer-reviewed literature and authoritative national and regional reports, and characterizes climate threats to USACE business lines, (e.g., flood risk management). They also provide context and linkage to other agency resources for climate resilience planning, such as downscaled climate data for subregions and watershed vulnerability assessment tools.
NOAA State Climate Summaries, 2017
NOAA has released a set of state climate summaries containing information on historical climate variations and trends, future climate model projections of climate conditions, and past and future conditions of sea level and coastal flooding.
These state climate summaries build on information provided in the 2014 National Climate Assessment and contain three types of information: key messages, narrative summaries, and downloads. The downloads include state summaries, high resolution figures suitable for report or presentations, and supplemental web graphics. The information contained in these state summaries can be used to supplement the regional literature assessments discussed above.
EPA Report on Climate Change Indicators in the US, 2016
EPA has released an externally peer-reviewed report describing a variety of climate change indicators in the US as of 2016. The information provided here gives a good national overview, with some regions highlighted for particular variables. The resources page lists other good sources of information. USACE staff should refer to projected policy, technical guidance, and tools developed for planning, design, and vulnerability assessments for more specific information on streamflow, sea level change, and factors impacting existing infrastructure.
US Global Research Program and the National Climate Assessment
The U.S. Global Research Program (USGRP) conducts periodic national climate assessments. These assessments inform the nation about already observed changes, the current status of the climate, and anticipated trends for the future. The assessments also integrate scientific information from multiple sources and sectors to highlight key findings and significant gaps in knowledge; and establish consistent methods for evaluating climate impacts in the U.S. in the context of broader global change.
In support of the National Climate Assessment (to be issued in 2014), the National Oceanic and Atmospheric Administration (NOAA) created a series of regional reports that examined current temperature and precipitation patterns, how those patterns will shift in the future, and how climate extremes are expected to increase by the end of the 21st century. In addition, a series of region-specific reports and reports on impacts to the transportation, energy and other sectors have been published as supporting documents for the forthcoming National Assessment. They are available from the website globalchange.gov.
The USGRP has also summarized these regional reports into two-page summaries of changes in climate (including possible future changes) summarizing overall nationwide trends and trends according to region, which include the Northeast, Southeast, Midwest, Great Plains, Northwest, Southwest, Alaska, and Hawai'i/Pacific Islands. The regional summaries focus on changes in temperature and precipitation, heat waves and extreme precipitation.
Western States: Bureau of Reclamation
The Bureau of Reclamation published a literature synthesis of climate impacts from a water resources manager's perspective for the 17 western states in 2010 (updated in 2013). This was followed in 2011 by the SECURE Water Act Section 9503(c) - Reclamation Climate Change and Water 2011 report, which assesses climate change risks and how these risks could impact water operations, hydropower, flood control, and fish and wildlife across the eight major Reclamation river basins in Western States.