Impacts of Climate Change on the State of Indiana: ensemble future projections based on statistical downscaling

Using an ensemble of 10 statistically downscaled global climate model (GCM) simulations, we project future climate change impacts on the state of Indiana (IN) for two scenarios of greenhouse-gas concentrations (a medium scenario--RCP4.5, and a high scenario--RCP 8.5) for three future time periods (2020s, 2050s, 2080s). Relative to a 1971-2000 baseline, the scenarios project substantial changes in temperature for IN, with a change in the annual ensemble mean temperature for the 2080s RCP8.5 scenario of about 5.6 °C (10.1 °F). Such changes also indicate major changes in extreme temperatures. For southern IN, the number of days with daily maximum temperatures above 35 °C (95 °F) is projected to be about 100 days per year for the 2080s RCP8.5 scenario, as opposed to an average of 5 days for the historical baseline climate. Locations in northern IN could experience 50 days per year above 35 °C (95 °F) for the same conditions. Energy demand for cooling, as measured by Cooling Degree Days (CDD), is projected to increase nearly fourfold in response to this extreme warming, but heating demand as measured by Heating Degree Days (HDD) is projected to decline by 30%, which would result in a net reduction in annual heating/cooling energy demand for consumers. The length of the growing season is projected to increase by about 30 to 50 days by the 2080s for the RCP8.5 scenario, and U.S. Department of Agriculture hardiness zones are projected to shift by about two half zones throughout IN. By the 2080s, all GCM simulations for the RCP8.5 scenario show higher annual precipitation (P) over IN. Projected seasonal changes in P include a 25-30% increase in winter and spring P by the 2080s for the RCP8.5 scenarios and a 1-7% decline in summer and fall P (although there is low model agreement in the latter two seasons). Rising temperatures are projected to result in systematic decreases in the snowfall-to-rain ratio from Nov-Mar. Snow is projected to become uncommon in southern IN by the 2080s for the RCP8.5 scenario, and snowfall is substantially reduced in other areas of the state. The combined effects of these changes in T, P, and snowfall will likely result in increased surface runoff and flooding during winter and spring

Climate robust culvert design: probabilistic estimates of fish passage impediments

*** This abstract is for a Snapshot (5-min) presentation. *** Many Washington State culverts are currently inadequate for fish passage. Apart from a few special cases, the standard for sizing culverts in Washington State is based on a simple linear function of bankfull width (BFW). This reflects a geomorphic approach to culvert design that can be applied across a large range of situations (Barnard et al. 2013, 2015). Future changes in BFW have previously been estimated by the Washington Department of Fish and Wildlife (WDFW) (Wilhere et al. 2016), by estimating the percent change in BFW derived from projected changes in runoff. This percent change can then be applied to direct observations of channel geometry. The main purpose of this talk is to present a novel new prototype for sizing culverts to account for the effects of climate change. The tool allows a user to enter some basic details about a culvert, choose a proposed design width, and evaluate the likelihood that it will fail to provide fish passage over a particular design lifetime. Likelihoods are estimated using a Monte Carlo approach, resulting in a probability distribution of future bankfull width. These probabilities will be used to assess the likelihood of culvert failure for different choices about how to size it. Since probabilities cannot be assigned to greenhouse gas scenarios, separate probabilities will be assessed for each greenhouse gas scenario, and likelihood estimates are produced for a given design lifetime. The talk will also include results from a recent evaluation of the climate and streamflow data used as the basis of the WDFW report. The work was funded by the Swinomish Indian Tribal Community (SITC) via the Skagit Climate Science Consortium (SC2)

Assessing Potential Winter Weather Response to Climate Change and Implications for Tourism in The U.S. Great Lakes and Midwest

Study Region: Eight U.S. states bordering the North American Laurentian Great Lakes. Study Focus: Variable Infiltration Capacity (VIC) model simulations, based on data from an en- semble of atmospheric-ocean general circulation models (AOGCMs) used for the Intergovernmental Panel on Climate Change\u27s (IPCC\u27s) Fifth Assessment Report (AR5), were used to quantify potential climate change impacts on winter weather and hydrology in the study re- gion and understand implications for its tourism sector. New Hydrologic Insights for the Region: By the 2080s, climate change could result in winters that are shorter by over a month, reductions of over a month in days with snow depths required for many kinds of winter recreation, declines in average holiday snow depths of 50 percent or more, and reductions in the percent area of the study region that would be considered viable for winter tourism from about 22 percent to 0.3 percent. Days with temperatures suitable for artificial snowmaking decline to less than a month annually, making it potentially less feasible as an adaptation strategy. All of the region\u27s current ski resorts are operating in areas that will become non-viable for winter tourism businesses under a high emissions scenario. Given the economic importance of the winter tourism industry in the study region, businesses and communities should consider climate change and potential adaptation strategies in their future planning and overall decision-making

Projecting the Hydrologic Impacts of Climate Change on Montane Wetlands

Wetlands are globally important ecosystems that provide critical services for natural communities and human society. Montane wetland ecosystems are expected to be among the most sensitive to changing climate, as their persistence depends on factors directly influenced by climate (e.g. precipitation, snowpack, evaporation). Despite their importance and climate sensitivity, wetlands tend to be understudied due to a lack of tools and data relative to what is available for other ecosystem types. Here, we develop and demonstrate a new method for projecting climate-induced hydrologic changes in montane wetlands. Using observed wetland water levels and soil moisture simulated by the physically based Variable Infiltration Capacity (VIC) hydrologic model, we developed site-specific regression models relating soil moisture to observed wetland water levels to simulate the hydrologic behavior of four types of montane wetlands (ephemeral, intermediate, perennial, permanent wetlands) in the U. S. Pacific Northwest. The hybrid models captured observed wetland dynamics in many cases, though were less robust in others. We then used these models to a) hindcast historical wetland behavior in response to observed climate variability (1916–2010 or later) and classify wetland types, and b) project the impacts of climate change on montane wetlands using global climate model scenarios for the 2040s and 2080s (A1B emissions scenario). These future projections show that climate-induced changes to key driving variables (reduced snowpack, higher evapotranspiration, extended summer drought) will result in earlier and faster drawdown in Pacific Northwest montane wetlands, leading to systematic reductions in water levels, shortened wetland hydroperiods, and increased probability of drying. Intermediate hydroperiod wetlands are projected to experience the greatest changes. For the 2080s scenario, widespread conversion of intermediate wetlands to fast-drying ephemeral wetlands will likely reduce wetland habitat availability for many species

Green and cool roofs to mitigate urban heat island effects in the Chicago metropolitan area: evaluation with a regional climate model

The effects of urban heat islands (UHIs) have a substantial bearing on the sustainability of cities and environs. This paper examines the efficacy of green and cool roofs as potential UHI mitigation strategies to make cities more resilient against UHI. We have employed the urbanized version of the Weather Research and Forecasting (uWRF) model at high (1 km) resolution with physically-based rooftop parameterization schemes (conventional, green and cool), a first-time application to the Chicago metropolitan area. We simulated a hot summer period (16–18 August 2013) and assessed (i) UHI reductions for different urban landuse with green/cool roofs, (ii) the interaction of lake breeze and UHI, and (iii) diurnal boundary layer dynamics. The performance of uWRF was evaluated using sensible heat flux and air temperature measurements from an urban mini-field campaign. The simulated roof surface energy balance captured the energy distribution with respective rooftop algorithms. Results showed that daytime roof temperature reduced and varied linearly with increasing green roof fractions, from less than 1 °C for the case of 25% green roof to ~3 °C during peak daytime for 100% green roof. Diurnal transitions from land to lake breeze and vice versa had a substantial impact on the daytime cycle of roof surface UHI, which had a 3–4 hour lag in comparison to 2 m UHI. Green and cool roofs reduced horizontal and vertical wind speeds and affected lower atmosphere dynamics, including reduced vertical mixing, lower boundary layer depth, and weaker convective rolls. The lowered wind speeds and vertical mixing during daytime led to stagnation of air near the surface, potentially causing air quality issues. The selection of green and cool roofs for UHI mitigation should therefore carefully consider the competing feedbacks. The new results for regional land-lake circulations and boundary layer dynamics from this study may be extended to other urbanized areas, particularly to coastal areas

Relative influences of human nutrient sources, the Pacific Ocean, and climate change on Salish Sea dissolved oxygen through 2070

The Department of Ecology and Pacific Northwest National Laboratory evaluated future dissolved oxygen scenarios within the Salish Sea using a circulation and water quality model of Puget Sound, the Strait of Georgia, and the Strait of Juan de Fuca. A recently published report summarizes relative contributions of human nutrient sources, the Pacific Ocean, and climate factors on dissolved oxygen both now and through 2070. Human nitrogen contributions from the U.S. and Canada to the Salish Sea have the greatest impacts on dissolved oxygen in portions of South and Central Puget Sound. Marine point sources cause greater impacts on oxygen than human influences on river inflows now and into the future. Most of the Salish Sea reflects a relatively low impact from human sources, although that will increase as loads increase. The Pacific Ocean strongly influences dissolved oxygen concentrations under both current and future conditions. If 50-year declining trends in North Pacific Ocean dissolved oxygen continue, Salish Sea dissolved oxygen would decline far more than from human nutrient loads. Climate change will alter the timing of freshwater flow reaching the Salish Sea, as provided by the University of Washington Climate Impacts Group. This would alter estuarine circulation patterns, potentially worsening impacts in some regions but lessening others. Future air temperature increases would further decrease dissolved oxygen, particularly in shallow inlets. This is the first assessment of how Salish Sea dissolved oxygen concentrations respond to population increases, ocean conditions, and climate change. Additional analyses are needed to link sediment-water interactions and increase scientific certainty

Indiana’s Past & Future Climate: A Report from the Indiana Climate Change Impacts Assessment

Indiana’s climate is changing. Temperatures are rising, more precipitation is falling and the last spring frost of the year has been getting steadily earlier. This report from the Indiana Climate Change Impacts Assessment (IN CCIA) describes historical climate trends from more than a century of data, and future projections that detail the ways in which our climate will continue to change

Preparing for Climatic Change: The Water, Salmon, and Forests of the Pacific Northwest

The impacts of year-to-year and decade-to-decade climatic variations on some of the Pacific Northwest’s key natural resources can be quantified to estimate sensitivity to regional climatic changes expected as part of anthropogenic global climatic change. Warmer, drier years, often associated with El Niño events and/or the warm phase of the Pacific Decadal Oscillation, tend to be associated with below-average snowpack, streamflow, and flood risk, below-average salmon survival, below-average forest growth, and above-average risk of forest fire. During the 20th century, the region experienced a warming of 0.8 ◦C. Using output from eight climate models, we project a further warming of 0.5–2.5 ◦C (central estimate 1.5 ◦C) by the 2020s, 1.5–3.2 ◦C (2.3◦C) by the 2040s, and an increase in precipitation except in summer. The foremost impact of a warming climate will be the reduction of regional snowpack, which presently supplies water for ecosystems and human uses during the dry summers. Our understanding of past climate also illustrates the responses of human management systems to climatic stresses, and suggests that a warming of the rate projected would pose significant challenges to the management of natural resources. Resource managers and planners currently have few plans for adapting to or mitigating the ecological and economic effects of climatic change