Informing Regional Analysis of the Impact of Climate Change
It has been three years since the Northeast Climate Impacts Assessment (NECIA) was released. The
assessment included studies of the effects of climate change on regional hydrology, phenology, forests,
marine fisheries, coastal infrastructure, tourism, and urban centers. Involving more than 50 scientists from
around the region, this comprehensive assessment quantified the risks of climate change if anthropogenic
greenhouse gas emissions unchecked, and the degree of impacts that would be inevitable even if emissions
are significantly reduced over the coming century. Climate projections generated by the assessment were
made available online, and comprehensive, high-resolution information was publicly available for regional
impact analyses. Today, nearly 400 users from academia, government, and non-profit organizations are using
the data to evaluate climate change impacts on an even broader range of sectors and in much more detail than
the original assessment. This study serves as an example of what can be done in a region, and in the
presentation we offer a summary of the lessons learned through this experience, and provide a template for
how this approach might be applied to other regions.
Projected Climate Change Impacts on Pennsylvania
We present an assessment of the potential impacts of human-induced climate change on the commonwealth of Pennsylvania, U.S.A. We first assess a suite of 21 global climate models for the state, rating them based on their ability to simulate the climate of Pennsylvania on time scales ranging from submonthly to interannual. The multi-model mean is superior to any individual model. Median projections by late century are 2-4 degrees C warming and 5-10 percent precipitation increases (B1 and A2 scenarios), with larger precipitation increases in winter and spring. Impacts on the commonwealth's aquatic and terrestrial ecosystems, water resources, agriculture, forests, energy, outdoor recreation, tourism, and human health, are evaluated. We also examine barriers and opportunities for Pennsylvania created by climate change mitigation. This assessment was sponsored by the Pennsylvania Department of Environmental Protection which, pursuant to the Pennsylvania Climate Change Act, Act 70 of 2008, is required to develop a report on the potential scientific and economic impacts of climate change to Pennsylvania.
Hydrologic Impacts of Projected Future Climate Change in the Lake Michigan Region
The Great Lakes are an important source of fresh water, recreation resource and transportation corridor for the Midwestern United States and Canada. The timing and quantity of fresh water inputs and how those may change under projections of future climate change are important for understanding how conditions, including river flows, and lake levels, within the region may be affected. Water quality and the density and diversity of in- stream habitats are responsive to changes in the distribution of daily streamflow, something not typically included in studies of climate change impacts. Projections of precipitation and air temperature changes in the four states surrounding Lake Michigan from the IPCC AR4 were downscaled and bias-corrected before being used to drive a large-scale hydrology model and produce maps of surface runoff and baseflow. These were then routed along drainage networks for regional rivers, and hydrologic metrics describing aspects of the distribution of daily flows important for hydrology and in-stream ecology were computed. The impact of regional climate change projections on early- (2010-2039) and mid-century (2040-2069) streamflow was highly variable; however, by the late-century period (2070-2099) annual streamflow was found to have increased in all rivers. Seasonally, winter and spring flows increased significantly by the late-century period, but summer flows become more variable with a decrease in low-flows and an increase in peak-flows. The number of days with flows above the annual mean-flow (TQmean) decreased in summer, but flashiness (R-B Index) increased. Seasonal soil frost and snow cover generally decrease by the late-century period, however, in the early- and late-century periods there are areas where decreases in snow cover yield increases in soil frost. Finally, simulations of regional lake ice cover indicate that historic trends towards fewer days with ice continue into the future, affecting the role of lakes and wetlands in the regional water and energy balance.
Regional Impacts of Climate Change in the Caribou Chilcotin Region, Fraser River Basin, BC, Canada
The terrain and climate of British Columbia (BC) is some of the most complex in the country, and is likely going to face unprecedented changes in hydrology due to the impacts of climate change. The Pacific Climate Impacts Consortium (PCIC) was formed in 2005 to produce tools to determine how water resources in BC and its surrounding provinces, territories and states are being affected by climate change. PCIC's first large-scale watershed modelling project implemented, in collaboration with the River Forecast Centre and the University of Washington, the Variable Infiltration Capacity (VIC) model in several major BC watersheds. Future scenarios were developed to analyse the impacts of climate change on snowpack, streamflow and soil moisture in these basins. The current study focuses on the methods to develop future scenarios and the results of the hydrologic modelling. Six different GCM emissions scenarios were selected for BC from the AR4 scenarios. A modified bias correction and statistical downscaling (BCSD) technique created at the University of Washington was used to downscale GCM results to the scale of gridded historical forcings data to generate transient-daily time step, regional-scale projections of future climate change. These forcings were then used to drive the VIC macro-scale hydrologic model. A comparison of forcings for the historical period (1961-1990) from the downscaled GCM data to the forcings created from the observed records on the monthly-timescale demonstrated that the downscaled data captured the range of variability present in the 1961-1990 period in large and medium sized basins quite well. Accurately downscaling data for application in small basins was more difficult. Daily results created with the original BCSD technique were unrealistic in places and problematic for application in hydrologic models, such as VIC that depend on an accurate daily temperature range to model evaporation and snowpack. Results for the Fraser Basin study include projected increases in winter mean precipitation (+15%, PCIC 2007) and increases in annual mean temperature (+2.5oC, PCIC 2007), which translate to changes in both streamflow volume and timing that will occur across the region. Other water balance components are also affected for example, despite an increase in winter time precipitation, warmer temperatures result in reduced snow accumulation. Higher winter time peak flows, and reduced snowpack storage and early season soil moisture results in lower water availability over summer periods. Hydrologic outputs from the VIC model and statistically downscaled GCM data were subsequently applied in stream temperature and fish habitat models to estimate the range of vulnerabilities of freshwater ecosystems to climate change in the Caribou Chilcotin region of the Fraser Basin. These changes could have impacts on fish habitats, hydro-power, agriculture and municipal water demand.
Modeling the Impossible Watershed': Simulating Climate Change Impacts on Streamflow in the Winnipeg River Basin.
With growing awareness of climate and human induced-impacts on environmental processes, hydrological modelling serves as an important tool necessary for sustainable water resource operation, management, and development. Recent trends toward climate extremes and short-term climate variability has necessitated that operators and policy-makers shift from statistically-based to more physically-based hydrological models to quantify operational adaptation measures. Using the WATFLOOD hydrological model, a physically-based mesoscale hydrological model developed at the University of Waterloo by Dr. Nicholas Kouwen, this research studies the effects of climate change on the flow regime in the Winnipeg River Basin (WRB), and the impacts of these changes on potential power production. Hydroelectric power production requires a detailed understanding of regional flow trends. In light of global climate change, it is beneficial for operational hydrologists to understand the effects of climate change on river flow regimes in order to better plan and adapt future management practices and operational procedures. Climate change scenarios were constructed in conjunction with Manitoba Hydro from a suite of Global Climate Model (GCM) simulations in accordance with scenarios set out by the Canadian Environmental Assessment Agency (CEAA). Projected changes in monthly averaged temperature and precipitation from these scenarios were used to modify the existing 92-year WRB historic record of weather events to produce synthetic climate scenarios as model forcing in WATFLOOD. Comparison of the streamflow hydrograph from perturbed climate to the historic record of flows at the locations of Manitoba Hydro's hydroelectric generating stations were then used to determine the changes in power potential on the Winnipeg River resulting from these projected climate scenarios. By studying the effects of climate change on power production, this research investigates the link between temperature and precipitation to runoff production and water availability; a step necessary to fully understand and quantify the physical impacts of climate change on surface hydrologic processes.
Studying Hydrological Response of the Churchill River to Climate Change Using Distributed Hydrological Models
The global climate has shown drastic changes in recent decades. It is of critical importance to investigate how global climate changes affect the different aspects of the hydrological cycle and the availability of freshwater resources in particular. In this study, the impact of climate change on the regional water and energy cycles in the Churchill River basin was assessed using distributed hydrological models. The applicability of the North American Regional Reanalysis (NARR) data for hydrological assessment in this remote region was also investigated. First monthly averaged precipitation and air temperature from NARR data were compared with a historical dataset interpolated using the ANUSPLIN method provided by the Canadian Forest service. The NARR data are available from 1979 to present at a 32-km resolution, while the interpolated dataset are available from 1950-2005 at a 5-km resolution. The NARR data was re-gridded to 5-km for comparison. The two datasets showed similar spatial distributions in multi-year precipitation and air temperature averaged from 1979 to 2005. A significant increase in the air temperature was also found in both datasets, especially in the winter. However, the air temperature in the NARR data was slightly higher, while the precipitation was slightly lower than the historical dataset. The WATFLOOD and Variable Infiltration Capacity (VIC) model were used to model the changes in the regional hydrological cycles in Churchill River during the past 30 years. The NARR data provided necessary inputs to the hydrological model, and the hydrological predictions including evapotranspiration, runoff, soil moisture and also snow water equivalent (SWE) from the NARR dataset were also examined through comparing with the outputs of the two models. The downscaling results from the Canadian regional climate (CRCM) model provided climate scenarios for the models to study the hydrological response to future climate change.