Critical Loads Critical Loads Tim Sullivan Tim Sullivan and and - PDF document

Critical Loads Critical Loads Critical Loads Critical Loads Tim Sullivan Tim Sullivan and and Jack Cosby Jack Cosby NYSERDA Conference NYSERDA Conference November 2007 November 2007 November, 2007 November, 2007 1

Critical Loads Critical Loads Background – – What are Critical What are Critical Background Loads? Loads? � � Definitions, biogeochemical basis, tools, Definitions, biogeochemical basis, tools, approaches, limitations approaches, limitations Objectives – – Why do we want Why do we want Objectives (need) Critical Loads? (need) Critical Loads? � � How do we want to use these tools in the How do we want to use these tools in the context of natural resource management in context of natural resource management in New York? New York? Methods – – How are Critical Loads How are Critical Loads Methods calculated? calculated? � � What is the policy context? What is the policy context? � � How can the results be used? How can the results be used? Results – – Results � � Some examples from the United States Some examples from the United States November, 2007 November, 2007 2

Critical Loads Critical Loads What is a Critical Load – – What is a Critical Load The definition: The definition: “Estimate of exposure to pollutants below Estimate of exposure to pollutants below “ which harmful effects on specified which harmful effects on specified sensitive elements of the environment do sensitive elements of the environment do not occur according to present knowledge” not occur according to present knowledge ” (Nilsson & Grennfelt Grennfelt, 1988) , 1988) (Nilsson & How was the concept developed? How was the concept developed? Developed in Europe for nitrogen and Developed in Europe for nitrogen and sulfur deposition, used in European sulfur deposition, used in European negotiations to establish emissions control negotiations to establish emissions control standards. standards. Why are Critical Loads used? Why are Critical Loads used? Based on the idea that control strategies Based on the idea that control strategies for acidification and eutrophication in for acidification and eutrophication in Europe should be effects- -driven. driven. Europe should be effects November, 2007 November, 2007 3

Critical Loads Critical Loads How are Critical Loads of pollutant How are Critical Loads of pollutant deposition determined – – the steps: the steps: deposition determined 1. Identify the disturbance disturbance produced by atmospheric produced by atmospheric 1. Identify the deposition of the pollutants (acidification, deposition of the pollutants (acidification, eutrophication, etc.) eutrophication, etc.) 2. Identify the receptors 2. Identify the receptors subject to the disturbance subject to the disturbance (forests, waters, crops, etc.) (forests, waters, crops, etc.) 3. Identify the biological indicators biological indicators to be protected to be protected 3. Identify the within each receptor (individual organism, within each receptor (individual organism, populations, community characteristics, etc) and populations, community characteristics, etc) and determine the critical indicator responses critical indicator responses that define that define determine the biological damage biological damage 4. 4. Identify the Identify the chemical variables chemical variables that control the that control the responses of the biological indicators and determine responses of the biological indicators and determine the the critical chemical limits critical chemical limits at which the critical at which the critical indicator responses occur indicator responses occur 5. Identify the atmospheric pollutants atmospheric pollutants that control the that control the 5. Identify the pertinent chemical variables (SO4, NO3, NH4, NH4, pertinent chemical variables (SO4, NO3, ozone, particulates, etc) and determine the critical ozone, particulates, etc) and determine the critical pollutant loads at which the chemical variables at which the chemical variables pollutant loads reach their critical limits reach their critical limits November, 2007 November, 2007 4

Critical Loads Critical Loads Why do we want Critical Loads? Why do we want Critical Loads? 1. Promote recovery to point where harmful effects no 1. Promote recovery to point where harmful effects no longer occur longer occur example: Adirondack lakes, Catskill streams example: Adirondack lakes, Catskill streams • • 2. Prevent future acidification and associated harmful 2. Prevent future acidification and associated harmful effects effects example: Adirondack soils and associated • example: Adirondack soils and associated • vegetation vegetation 3. Head off effects associated with future nitrogen 3. Head off effects associated with future nitrogen saturation saturation example: episodic stream acidification • example: episodic stream acidification • 4. 4. Integrate knowledge of effects from multiple Integrate knowledge of effects from multiple pollutants pollutants example: NOx, NH 4 , S, Hg • example: NOx, NH 4 , S, Hg • 5. Set targets, develop management goals 5. Set targets, develop management goals example: when have we accomplished recovery? • example: when have we accomplished recovery? • November, 2007 November, 2007 5

Critical Loads Critical Loads Determining Critical Loads – – the the Determining Critical Loads steps steps 1) Disturbance Acidification Eutrophication 2) Receptor Forest Lake Grassland Lake 3) Biological Sugar Norway Brook Fish Species Primary Maple Spruce trout species diversity productivity indicator richness 4) Chemical Soil % Soil Ca/Al Lakewater Lakewater Soil C/N Lakewater Base ratio ANC ANC NO3 variable Saturation 5) Atmospheric SO4, NO3, SO4, SO4, NO3, SO4, NO3, NO3, NO3, NH4 NH4 NO3, NH4 NH4 NH4 pollutant NH4 November, 2007 November, 2007 6

Critical Loads Critical Loads biological indicator response value of chemical variable Response Function Response Function Biological Indicator is a function of Chemical Variable Biological Indicator is a function of Chemical Variable Biological Indicator Responses Biological Indicator Responses Chemical Variables Chemical Variables Death of organisms Condition of individuals ANC, pH, NO3, Al Reproductive success Base saturation, Ca/Al Ozone Loss of species Community productivity Annual averages Seasonal extremes November, 2007 November, 2007 7

Critical Loads Critical Loads biological indicator response critical chemical limit critical indicator response value of chemical variable Response Function Response Function Biological Indicator is a function of Chemical Variable Biological Indicator is a function of Chemical Variable Biological Indicator Responses Biological Indicator Responses Chemical Variables Chemical Variables Death of organisms Condition of individuals ANC, pH, NO3, Al Reproductive success Base saturation, Ca/Al Ozone Loss of species Community productivity Annual averages Seasonal extremes November, 2007 November, 2007 8

Critical Loads Critical Loads value of chemical variable pollutant load Response Function Response Function Chemical Variable is a function of Pollutant Load Chemical Variable is a function of Pollutant Load Chemical Variables Chemical Variables Pollutant Load Pollutant Load S, N ANC, pH, NO3, Al Hg, NOx, SO2 Base saturation, Ca/Al Ozone Annual averages Seasonal patterns Annual averages Seasonal extremes November, 2007 November, 2007 9

Critical Loads Critical Loads value of chemical variable critical pollutant load critical chemical limit pollutant load Response Function Response Function Chemical Variable is a function of Pollutant Load Chemical Variable is a function of Pollutant Load Chemical Variables Chemical Variables Pollutant Load Pollutant Load S, N ANC, pH, NO3, Al Hg, Nox, SO2 Base saturation, Ca/Al Ozone Annual averages Seasonal patterns Annual averages Seasonal extremes November, 2007 November, 2007 10

Critical Loads Critical Loads biological indicator response critical pollutant load critical indicator response pollutant load Combined Response Function Combined Response Function Biological Indicator is a function of Pollutant Load Biological Indicator is a function of Pollutant Load Biological Indicator Biological Indicator Chemical Chemical Pollutant Load Pollutant Load Responses Responses Variables Variables Death of organisms ANC, pH, NO3, Al S, N Condition of individuals Base saturation, Hg, NOx, SO2 Reproductive success Ca/Al Ozone Annual averages Loss of species Annual averages Seasonal patterns Community Seasonal extremes productivity November, 2007 November, 2007 11