Sustainable Development (NAS) A process of reconciling society’s developmental needs with the environmental limits over the long term. It includes differing views on what should be developed, what should be sustained and over what time period. Human activities exert pressures, such as burning fossil fuels that alter the state of environment, such air quality. The impaired environmental state, elicits responses, such as regulations in a Pressure-State-Response (PSR) feedback loop system. These three classes of variables can be measured using data that are collected for administrative purposes. Combining these data with a simple but flexible scenario captures a fundamental idea of sustainable development The NAS (1999) describes SD as an uncertain and adaptive process, “ in which society's discovery of where it wants to go is intertwined with how it might try to get there ”. During the ‘ journey ’, the pathways of a transition to sustainability have to be ‘ navigated ’ adaptively at many scales and in many places.

Sustainable Development – Causality Loop Economic Development with Due Care of the Environment The system approach links human activities and their consequences in closed loop It is the minimum set of linked components – if any missing, the system is crippled Each component depends on its causal upstream driver – and external environment The causal loop can be used as an organizing principle for sustainability analysis

Causality: Linear System Model

Analysis Framework III – Causality Loop Economic Development with Due Care of the Environment Health-Welfare Energy- Environment Socio-Economic (OzPolitic)OzPolitic

Trend of Indicators

Indications and Drivers of Change Causality Framework: Population  Economy  Energy  Pollution These are measurable indicators, to be monitored for sustainability Causality Model SOx = Pop x GDP/P x Btu/GDP x Sox/Btu Drivers of Change: Population [person, P] Economy/Person [$ GDP/person] Energy/Economy [Btu/$GDP] Pollution/Energy [Pollution/Btu]

Trend of Indicators

Population  Economy  Energy  Pollution SOx = Pop x GDP/P x Btu/GDP x Sox/Btu 1960s 1970s 1980s 1990s

Population - Energy/Goods Consumption– Materials Flow - Emissions E k =  c jk EM j =   b ij c jk GE i =    a i b ij c jk P Industr. Energy Transp. Energy ResCom.Engy Coal Oil GasElectric Energy SOx NOx HC PM Goods &Energy,(GE) iFuels&Mater.(FM), j Emission (EM), k Ind. Chemicals Industr. Goods Pop., P Metals Mercury a i Consump./Person b ij Fuels/Energy c jk Emission/Fuel- jjiiij Consumption of Goods and Energy:GE =  a i P Fuels and Materials Flow:FM =   a i b ij P Emission of Pollutants:EM =    a i b ij c jk P Industrial Prod. Transportation ResComercial EconMeasure(EM)

Miles/ Vehicle Vehicle/ Person Energy/ Mile Carbon/ Energy PersonsVehiclesMilesGallonsCarbon P XXXX OccupancyVMT, PMT, FTMEnergy Effic.Carbon Causality Factor Transportation Causality Chain: The need to move people and goods drives the carbon emission trend.

Vehicle, Passenger and Freight Miles Traveled: Vehicle Miles Traveled (VMT) is equal to the weighted sum of the number of vehicle-miles traveled by each vehicle in the surveyed sample. The calculations are based on odometer readings at the beginning and end of the year. Movement of People: Passenger miles are the number of miles traveled by a person per year Movement of Goods: Freight ton miles are calculated by multiplying the amount of weight (in tons) by the distance that the weight has traveled. Vehicle Categories included: Air, Car, Heavy Truck, Bus, Rail and Other

Vehicle Occupancy: The number of occupants per vehicle is largely dependent on the purpose of the trip.. Occupancy is the efficiency of travel Occupancy = PMT/VMT Occupancy has been decreasing steadily for passenger cars since 1960 from almost two people/car to one car for every person.

Fuel Efficiency: It is expressed in Btu/miles and is driven by two parameters: category of the vehicle and specific type in the category. Passenger cars have the highest fuel efficiency. Carbon emissions are inversely proportional to fuel efficiency, thus a passenger car causes the least emissions compared to trucks and other 2- axle 4-tire vehicles. Trucks are the least fuel efficient vehicles. The overall trend is of more efficient vehicles. The direct effect of this trend is a decrease of carbon emissions for these three categories of vehicles. *Two sources were used to confirm the data

Carbon Emission by Transportation Sector (by ground vehicles, excluding rail) At the current rate of growth, the US national carbon emissions due to ground transportation would double every 30 years