Conclusions and Critical Information Gaps
We offer a general observation to put climate changes in perspective. In the next several decades, non-climate factors are more likely to impact water resources in New York State than climate factors. For instance, water supplies are most likely to be stressed by increasing demands and insufficient coordination of supplies than by a dramatic downward shift in the availability of water. Water quality is more likely to be harmed by aging waste water treatment plants, continued combined sewer overflow events, and excess nutrient loading in agricultural regions. Additionally, the region is already subject to large variations in climate, even without human-induced climate change. For example, major upland flooding is most likely to be caused by hurricanes or other major coastal storms. Therefore, nearly all our suggested adaptations are intended to address these non-climate change factors in tandem with the challenges posed by climate change.
In Table 3, vulnerabilities have been divided into categories that parallel the organization of this web site: Flooding, Drinking Water Supply, Commercial and Agricultural Water Availability, and Water Quality. No one vulnerability takes precedence since no vulnerability can be identified at this time as having a disproportionate societal or economic impact on the state. Additionally, some items listed are only potential vulnerabilities that require additional time and information before a more definitive determination of their importance can be made.
A Framework for Considering Adaptation Strategies
This report identifies the type and magnitude of potential impacts to New York State's water resources in a changing climate. Several adaptation pathways arise from this evaluation that can reduce the potential negative consequences of climate change. A challenge to building resilience, however, is the lack of certainty in the degree, pace, and even direction of climate-hydrologic changes anticipated for New York State. Water resource managers will need to make decisions based on climate projections that reflect this uncertainty, which is very different from contemporary approaches that rely on the historical record and the assumption of a stationary climate.
Our near-term climate change adaptation recommendations for New York State's water resources are primarily formulated to address this uncertainty In the context of decision making science, the term robustness is defined as being a strategy that is effective (in terms of cost, societal impact, and risk reduction) under a range of possible future outcomes (Lempert et al. 2006). Hallegatte (2009) has recently outlined several robust decision making strategies, and we supplement them with several categories of our own:
- Strategic expenditures on "no regret" options that result in a net public benefit whether or not climate change projections are realized.
- Taking advantage of low-cost margins of safety in new construction to avoid more expensive retrofits and modifications in the future.
- Soft strategies (in contrast to "hard" infrastructure solutions) that seek to build new institutional or organizational frameworks.
- Robust monitoring efforts that expand the collection of environmental data which are critical for making management decisions.
The full report places the adaptation options presented throughout the web page into one of the four categories of robust decision making strategies.
Critical Information Gaps
There are many areas involving climate change impacts to water resources where educated decisions cannot be made until a better understanding of fundamental processes is obtained. Below, five primary areas requiring further research are summarized.
- In terms of protecting water quality, there is a need for additional applied research to identify critical pollutant contributing areas and processes. Adaptation measures for water quality protection in a changing climate should be targeted to the critical areas and processes rather than intervening with multiple management options across entire watersheds without regard to the primary pollution source (Garbrecht et al., 2007). At small scale, there should be a critical field-based assessment of the effectiveness of best management practices. At a larger spatial scale, improved monitoring of primary nutrients, turbidity, and pathogen indicators on major rivers (Chemung, upper Susquehanna, and Delaware) would enable a clearer picture to emerge of the association between climate factors, land use and water quality in NYS.
- More severe climate changes in other parts of the US (relative to the Northeast) could shift population growth and water-intensive economic back towards states like NYS. A state wide water plan could provide guidance to commercial and industrial entities, as well as homebuilders and home buyers, on which communities in the state have the most excess water supplies, even with the additional stress of climate change. Additionally, a state water plan could initiate thinking into potential economic opportunities, and the private sector would presumably have an incentive to further investigate the possibilities.
- There are several fundamental hydrologic processes that need more in-depth assessment. In particular, there is a need for better understanding of groundwater recharge, stream low-flows, evaporation, and flooding in a changing climate. Such studies need to be processed based, instead of simply drawing conclusions from looking at empirical relationships in historical data. Additionally, they need to specifically look at processes within the region and avoid making generalizations from other areas, a typical limitation of many existing studies. Such studies would benefit from additional data, much of which could come from a refinement of existing monitoring networks. The existing rain gage network could be expanded to insure there is a satisfactory density of rain gages in each basin with a stream gage, permitting a better understanding of the hydrologic response in gaged basins. Potential evapotranspiration as well as soil moisture could also be measured at several sites across the state to better understand how evaporation is impacted by changing climate factors. Finally, snow depth measurements could start to include snow water equivalents (reporting snow as a depth of liquid water to account for snow compaction and differences in density) in order to provide a more objective measure of how snow fall and snow packs are changing over time.
- Many pollutant discharge permits for WWTPs are based on streamflow and temperature data from decades ago. An assessment should be carried out to estimate future streamflow and water temperature scenarios and to model what impact these changes will have on the quality of water bodies receiving effluent.
- There is often a desire for "actionable" future climate information for making decisions on infrastructure needs or policy changes. A hard number could be provided by downscaling GCM projections and using these as input to a hydrologic or ecology model, but the reality is that this model estimate would be far from certain. Therefore, there is a need for a fundamental shift in the way engineers, planners, and policy makers make decisions. Instead of devising a strategy optimized for one outcome, the strategy should instead perform effectively (in terms of cost, societal impact, and risk reduction) across many outcomes, termed robustness. There needs to be both basic research as well as educational outreach to decision makers to expand the concept of robust decision making.
Garbrecht, J.D. J.L. Steiner, and C.A. Cox. 2007. The times they are changing: soil and water conservation in the 21st century. Hydrological Processes, 21: 2677-2679.
Hallegatte, S. 2009 Strategies to adapt to an uncertain climate. Global Environmental Change, 19: 240-247.
Lempert, RJ, and MT Collins. 2007. Managing the risk of uncertain threshold responses: comparison of robust, optimum, and precautionary approaches. Risk Analysis, 27:1009-1026.
Climate Change Links
Intergovernmental Panel on Climate Change (IPCC) (link)
Northeast Climate Choices (UCS Reports) (link)
Climate Change and Northeast Agriculture (link)
Climate Change and Water Resources (NCAR) (link)
USDA Global Change Program Office (GCPO) (link)