CO2e Emissions = Activity Data × Emission Factor
 
Where:
  Activity Data = Quantity of activity (kWh, liters, kg, tkm, etc.)
  Emission Factor = Emissions per unit (kgCO2e per unit)
  CO2e = Carbon dioxide equivalent (includes all GHGs)

import pandas as pd
import numpy as np
class CarbonFootprintCalculator:
    """Comprehensive carbon footprint calculator"""
    def __init__(self):
        self.emission_factors = self._load_emission_factors()
        self.gwp_factors = {
            'CO2': 1,
            'CH4': 25,      # Methane (100-year GWP)
            'N2O': 298,     # Nitrous oxide
            'HFCs': 1430,   # Hydrofluorocarbons (avg)
            'PFCs': 7390,   # Perfluorocarbons (avg)
            'SF6': 22800    # Sulfur hexafluoride
        }
    def _load_emission_factors(self):
        """Load standard emission factors database"""
        # Based on EPA, DEFRA, and other sources
        return {
            # Energy (kgCO2e per kWh)
            'electricity_us_grid': 0.417,
            'electricity_eu_grid': 0.295,
            'electricity_renewable': 0.000,
            'natural_gas': 0.202,  # per kWh
            # Fuels (kgCO2e per liter)
            'diesel': 2.68,
            'gasoline': 2.31,
            'jet_fuel': 2.50,
            # Transportation (kgCO2e per tonne-km)
            'truck_full_truckload': 0.062,
            'truck_less_than_truckload': 0.091,
            'rail': 0.022,
            'ocean_shipping': 0.008,
            'air_freight': 0.602,
            # Materials (kgCO2e per kg)
            'steel': 1.85,
            'aluminum': 8.24,
            'plastic_pet': 2.15,
            'cardboard': 0.95,
            'glass': 0.85,
            'concrete': 0.11,
            # Manufacturing (kgCO2e per unit - examples)
            'electronics_assembly': 50,
            'textile_production': 15,
            'food_processing': 2.5
        }
    def calculate_scope1_facilities(self, fuel_consumption):
        """
        Calculate Scope 1 emissions from facility fuel use
        fuel_consumption: dict with fuel types and quantities
        Example: {'diesel_liters': 10000, 'natural_gas_kwh': 50000}
        """
        emissions = 0
        breakdown = []
        # Diesel/gasoline combustion
        if 'diesel_liters' in fuel_consumption:
            diesel_co2 = fuel_consumption['diesel_liters'] * self.emission_factors['diesel']
            emissions += diesel_co2
            breakdown.append({
                'source': 'Diesel combustion',
                'activity': fuel_consumption['diesel_liters'],
                'unit': 'liters',
                'emissions_kgco2e': diesel_co2
            })
        if 'gasoline_liters' in fuel_consumption:
            gas_co2 = fuel_consumption['gasoline_liters'] * self.emission_factors['gasoline']
            emissions += gas_co2
            breakdown.append({
                'source': 'Gasoline combustion',
                'activity': fuel_consumption['gasoline_liters'],
                'unit': 'liters',
                'emissions_kgco2e': gas_co2
            })
        # Natural gas (converted to kWh)
        if 'natural_gas_kwh' in fuel_consumption:
            ng_co2 = fuel_consumption['natural_gas_kwh'] * self.emission_factors['natural_gas']
            emissions += ng_co2
            breakdown.append({
                'source': 'Natural gas',
                'activity': fuel_consumption['natural_gas_kwh'],
                'unit': 'kWh',
                'emissions_kgco2e': ng_co2
            })
        return {
            'scope': 'Scope 1',
            'total_emissions_kgco2e': round(emissions, 2),
            'total_emissions_tco2e': round(emissions / 1000, 2),
            'breakdown': breakdown
        }
    def calculate_scope1_fleet(self, vehicle_data):
        """
        Calculate Scope 1 emissions from company fleet
        vehicle_data: list of dicts with vehicle info
        Example: [{'type': 'diesel', 'distance_km': 50000, 'fuel_efficiency_l_per_100km': 8}]
        """
        emissions = 0
        breakdown = []
        for vehicle in vehicle_data:
            distance = vehicle['distance_km']
            fuel_efficiency = vehicle['fuel_efficiency_l_per_100km']
            fuel_type = vehicle['type']
            # Calculate fuel consumed
            fuel_consumed = (distance / 100) * fuel_efficiency
            # Get emission factor
            if fuel_type in ['diesel']:
                ef = self.emission_factors['diesel']
            elif fuel_type in ['gasoline', 'petrol']:
                ef = self.emission_factors['gasoline']
            else:
                ef = 2.5  # default
            vehicle_emissions = fuel_consumed * ef
            emissions += vehicle_emissions
            breakdown.append({
                'vehicle_id': vehicle.get('id', 'Unknown'),
                'fuel_type': fuel_type,
                'distance_km': distance,
                'fuel_consumed_liters': round(fuel_consumed, 2),
                'emissions_kgco2e': round(vehicle_emissions, 2)
            })
        return {
            'scope': 'Scope 1 - Fleet',
            'total_emissions_kgco2e': round(emissions, 2),
            'total_emissions_tco2e': round(emissions / 1000, 2),
            'breakdown': breakdown
        }
    def calculate_scope2_electricity(self, electricity_consumption, region='us', renewable_pct=0):
        """
        Calculate Scope 2 emissions from electricity
        electricity_consumption: kWh consumed
        region: 'us', 'eu', or custom
        renewable_pct: percentage of renewable energy (0-1)
        """
        # Select emission factor based on region
        if region == 'us':
            ef = self.emission_factors['electricity_us_grid']
        elif region == 'eu':
            ef = self.emission_factors['electricity_eu_grid']
        else:
            ef = 0.40  # global average
        # Adjust for renewable percentage
        grid_electricity = electricity_consumption * (1 - renewable_pct)
        renewable_electricity = electricity_consumption * renewable_pct
        emissions_grid = grid_electricity * ef
        emissions_renewable = renewable_electricity * self.emission_factors['electricity_renewable']
        total_emissions = emissions_grid + emissions_renewable
        return {
            'scope': 'Scope 2',
            'total_electricity_kwh': electricity_consumption,
            'grid_electricity_kwh': grid_electricity,
            'renewable_electricity_kwh': renewable_electricity,
            'emission_factor_kgco2e_per_kwh': ef,
            'total_emissions_kgco2e': round(total_emissions, 2),
            'total_emissions_tco2e': round(total_emissions / 1000, 2)
        }
    def calculate_scope3_transportation(self, shipments):
        """
        Calculate Scope 3 emissions from transportation
        shipments: list of dicts
        Example: [{'mode': 'truck_ftl', 'distance_km': 500, 'weight_tonnes': 20}]
        """
        emissions = 0
        breakdown = []
        for shipment in shipments:
            mode = shipment['mode']
            distance = shipment['distance_km']
            weight = shipment['weight_tonnes']
            # Calculate tonne-kilometers
            tkm = distance * weight
            # Get emission factor
            mode_map = {
                'truck_ftl': 'truck_full_truckload',
                'truck_ltl': 'truck_less_than_truckload',
                'rail': 'rail',
                'ocean': 'ocean_shipping',
                'air': 'air_freight'
            }
            ef_key = mode_map.get(mode, 'truck_full_truckload')
            ef = self.emission_factors[ef_key]
            shipment_emissions = tkm * ef
            emissions += shipment_emissions
            breakdown.append({
                'shipment_id': shipment.get('id', 'Unknown'),
                'mode': mode,
                'distance_km': distance,
                'weight_tonnes': weight,
                'tonne_km': tkm,
                'emission_factor': ef,
                'emissions_kgco2e': round(shipment_emissions, 2)
            })
        return {
            'scope': 'Scope 3 - Transportation',
            'total_emissions_kgco2e': round(emissions, 2),
            'total_emissions_tco2e': round(emissions / 1000, 2),
            'breakdown': breakdown
        }
    def calculate_scope3_materials(self, materials_purchased):
        """
        Calculate Scope 3 emissions from purchased materials
        materials_purchased: dict with material types and quantities (kg)
        Example: {'steel': 10000, 'plastic_pet': 5000}
        """
        emissions = 0
        breakdown = []
        for material, quantity_kg in materials_purchased.items():
            if material in self.emission_factors:
                ef = self.emission_factors[material]
                material_emissions = quantity_kg * ef
                emissions += material_emissions
                breakdown.append({
                    'material': material,
                    'quantity_kg': quantity_kg,
                    'emission_factor': ef,
                    'emissions_kgco2e': round(material_emissions, 2)
                })
        return {
            'scope': 'Scope 3 - Materials',
            'total_emissions_kgco2e': round(emissions, 2),
            'total_emissions_tco2e': round(emissions / 1000, 2),
            'breakdown': breakdown
        }
    def calculate_product_carbon_footprint(self, product_data):
        """
        Calculate product-level carbon footprint (cradle-to-gate)
        product_data: dict with all product lifecycle data
        """
        total_emissions = 0
        lifecycle_breakdown = {}
        # Materials extraction and processing
        if 'materials' in product_data:
            materials_result = self.calculate_scope3_materials(product_data['materials'])
            lifecycle_breakdown['materials'] = materials_result
            total_emissions += materials_result['total_emissions_kgco2e']
        # Manufacturing
        if 'manufacturing' in product_data:
            mfg_energy = product_data['manufacturing'].get('energy_kwh', 0)
            mfg_result = self.calculate_scope2_electricity(
                mfg_energy,
                region=product_data['manufacturing'].get('region', 'us')
            )
            lifecycle_breakdown['manufacturing'] = mfg_result
            total_emissions += mfg_result['total_emissions_kgco2e']
        # Transportation to customer
        if 'transportation' in product_data:
            transport_result = self.calculate_scope3_transportation(
                product_data['transportation']
            )
            lifecycle_breakdown['transportation'] = transport_result
            total_emissions += transport_result['total_emissions_kgco2e']
        # Use phase (if applicable)
        if 'use_phase' in product_data:
            use_emissions = product_data['use_phase'].get('emissions_kgco2e', 0)
            lifecycle_breakdown['use_phase'] = {
                'emissions_kgco2e': use_emissions
            }
            total_emissions += use_emissions
        # End of life
        if 'end_of_life' in product_data:
            eol_emissions = product_data['end_of_life'].get('emissions_kgco2e', 0)
            lifecycle_breakdown['end_of_life'] = {
                'emissions_kgco2e': eol_emissions
            }
            total_emissions += eol_emissions
        return {
            'product_id': product_data.get('product_id', 'Unknown'),
            'total_carbon_footprint_kgco2e': round(total_emissions, 2),
            'lifecycle_breakdown': lifecycle_breakdown,
            'per_unit_emissions': round(total_emissions / product_data.get('units', 1), 2)
        }
    def calculate_emissions_by_scope(self, scope1_data, scope2_data, scope3_data):
        """Generate comprehensive emissions inventory by scope"""
        scope1_result = self.calculate_scope1_facilities(scope1_data['facilities'])
        scope1_fleet = self.calculate_scope1_fleet(scope1_data['fleet'])
        scope2_result = self.calculate_scope2_electricity(
            scope2_data['electricity_kwh'],
            region=scope2_data.get('region', 'us'),
            renewable_pct=scope2_data.get('renewable_pct', 0)
        )
        scope3_transport = self.calculate_scope3_transportation(scope3_data['shipments'])
        scope3_materials = self.calculate_scope3_materials(scope3_data['materials'])
        total_scope1 = (scope1_result['total_emissions_kgco2e'] +
                       scope1_fleet['total_emissions_kgco2e'])
        total_scope2 = scope2_result['total_emissions_kgco2e']
        total_scope3 = (scope3_transport['total_emissions_kgco2e'] +
                       scope3_materials['total_emissions_kgco2e'])
        total_emissions = total_scope1 + total_scope2 + total_scope3
        return {
            'total_emissions_tco2e': round(total_emissions / 1000, 2),
            'scope1_tco2e': round(total_scope1 / 1000, 2),
            'scope2_tco2e': round(total_scope2 / 1000, 2),
            'scope3_tco2e': round(total_scope3 / 1000, 2),
            'scope1_percentage': round(total_scope1 / total_emissions * 100, 1),
            'scope2_percentage': round(total_scope2 / total_emissions * 100, 1),
            'scope3_percentage': round(total_scope3 / total_emissions * 100, 1),
            'detailed_results': {
                'scope1_facilities': scope1_result,
                'scope1_fleet': scope1_fleet,
                'scope2_electricity': scope2_result,
                'scope3_transportation': scope3_transport,
                'scope3_materials': scope3_materials
            }
        }
# Example usage
calculator = CarbonFootprintCalculator()
# Example calculation
scope1_data = {
    'facilities': {
        'diesel_liters': 5000,
        'natural_gas_kwh': 100000
    },
    'fleet': [
        {'id': 'V001', 'type': 'diesel', 'distance_km': 50000, 'fuel_efficiency_l_per_100km': 8},
        {'id': 'V002', 'type': 'diesel', 'distance_km': 30000, 'fuel_efficiency_l_per_100km': 9}
    ]
}
scope2_data = {
    'electricity_kwh': 500000,
    'region': 'us',
    'renewable_pct': 0.20  # 20% renewable
}
scope3_data = {
    'shipments': [
        {'id': 'S001', 'mode': 'truck_ftl', 'distance_km': 800, 'weight_tonnes': 20},
        {'id': 'S002', 'mode': 'ocean', 'distance_km': 5000, 'weight_tonnes': 100},
        {'id': 'S003', 'mode': 'air', 'distance_km': 2000, 'weight_tonnes': 2}
    ],
    'materials': {
        'steel': 50000,
        'plastic_pet': 10000,
        'cardboard': 5000
    }
}
results = calculator.calculate_emissions_by_scope(scope1_data, scope2_data, scope3_data)
print(f"Total Emissions: {results['total_emissions_tco2e']} tCO2e")
print(f"Scope 1: {results['scope1_tco2e']} tCO2e ({results['scope1_percentage']}%)")
print(f"Scope 2: {results['scope2_tco2e']} tCO2e ({results['scope2_percentage']}%)")
print(f"Scope 3: {results['scope3_tco2e']} tCO2e ({results['scope3_percentage']}%)")

class SupplierEmissionsTracker:
    """Track and manage supplier carbon footprint data"""
    def __init__(self):
        self.suppliers = {}
        self.data_quality_tiers = {
            'tier1_primary': 1.0,      # Supplier-specific verified data
            'tier2_secondary': 0.8,    # Industry averages
            'tier3_estimated': 0.5     # Spend-based estimates
        }
    def add_supplier(self, supplier_id, supplier_name, spend, emissions_data):
        """
        Add supplier with emissions data
        emissions_data: dict with emissions info and data quality
        """
        self.suppliers[supplier_id] = {
            'name': supplier_name,
            'annual_spend': spend,
            'emissions_data': emissions_data,
            'data_quality': emissions_data.get('data_quality', 'tier3_estimated'),
            'last_updated': pd.Timestamp.now()
        }
    def calculate_supplier_emissions(self, supplier_id):
        """Calculate emissions for a specific supplier"""
        supplier = self.suppliers[supplier_id]
        emissions_data = supplier['emissions_data']
        if supplier['data_quality'] == 'tier1_primary':
            # Use supplier-reported data
            return emissions_data.get('reported_emissions_tco2e', 0)
        elif supplier['data_quality'] == 'tier2_secondary':
            # Use industry average emission factors
            category = emissions_data.get('category', 'general_manufacturing')
            revenue = emissions_data.get('revenue', 1000000)
            # Industry emission intensities (tCO2e per $1M revenue)
            intensity_map = {
                'general_manufacturing': 120,
                'electronics': 80,
                'chemicals': 250,
                'textiles': 150,
                'food_processing': 90,
                'logistics': 200
            }
            intensity = intensity_map.get(category, 100)
            emissions = (revenue / 1000000) * intensity
            return emissions
        else:  # tier3_estimated
            # Spend-based estimation
            spend = supplier['annual_spend']
            # Average emission factor: tCO2e per $1000 spend
            spend_emission_factor = 0.5
            emissions = (spend / 1000) * spend_emission_factor
            return emissions
    def generate_supplier_emissions_report(self):
        """Generate comprehensive supplier emissions report"""
        report_data = []
        for supplier_id, supplier in self.suppliers.items():
            emissions = self.calculate_supplier_emissions(supplier_id)
            data_quality = supplier['data_quality']
            quality_score = self.data_quality_tiers[data_quality]
            report_data.append({
                'supplier_id': supplier_id,
                'supplier_name': supplier['name'],
                'annual_spend': supplier['annual_spend'],
                'emissions_tco2e': round(emissions, 2),
                'data_quality': data_quality,
                'quality_score': quality_score,
                'emissions_intensity_per_1k_spend': round(emissions / (supplier['annual_spend'] / 1000), 2)
            })
        df = pd.DataFrame(report_data)
        # Sort by emissions descending
        df = df.sort_values('emissions_tco2e', ascending=False)
        # Calculate cumulative percentage
        total_emissions = df['emissions_tco2e'].sum()
        df['cumulative_pct'] = df['emissions_tco2e'].cumsum() / total_emissions * 100
        # Classify suppliers by emissions contribution
        df['classification'] = df['cumulative_pct'].apply(
            lambda x: 'A (High)' if x <= 80 else ('B (Medium)' if x <= 95 else 'C (Low)')
        )
        return df
    def identify_engagement_priorities(self, threshold_pct=80):
        """Identify suppliers to prioritize for emissions reduction engagement"""
        df = self.generate_supplier_emissions_report()
        # Prioritize suppliers contributing to top 80% of emissions
        priority_suppliers = df[df['cumulative_pct'] <= threshold_pct].copy()
        # Also prioritize poor data quality with high spend
        high_spend_poor_quality = df[
            (df['annual_spend'] > df['annual_spend'].quantile(0.75)) &
            (df['quality_score'] < 0.7)
        ]
        # Combine
        priority_list = pd.concat([priority_suppliers, high_spend_poor_quality]).drop_duplicates()
        return priority_list.sort_values('emissions_tco2e', ascending=False)
# Example usage
tracker = SupplierEmissionsTracker()
# Add suppliers
tracker.add_supplier(
    'SUP001',
    'Acme Manufacturing',
    spend=5000000,
    emissions_data={
        'reported_emissions_tco2e': 8500,
        'data_quality': 'tier1_primary',
        'verification': 'third_party'
    }
)
tracker.add_supplier(
    'SUP002',
    'Beta Chemicals',
    spend=3000000,
    emissions_data={
        'category': 'chemicals',
        'revenue': 50000000,
        'data_quality': 'tier2_secondary'
    }
)
tracker.add_supplier(
    'SUP003',
    'Gamma Logistics',
    spend=1500000,
    emissions_data={
        'data_quality': 'tier3_estimated'
    }
)
# Generate report
report = tracker.generate_supplier_emissions_report()
print(report[['supplier_name', 'emissions_tco2e', 'data_quality', 'classification']])
# Identify priorities
priorities = tracker.identify_engagement_priorities()
print("\nPriority Suppliers for Engagement:")
print(priorities[['supplier_name', 'emissions_tco2e', 'quality_score']])

class CarbonReductionPlanner:
    """Identify and prioritize carbon reduction opportunities"""
    def __init__(self, baseline_emissions):
        self.baseline_emissions = baseline_emissions
        self.reduction_initiatives = []
    def add_initiative(self, initiative_name, category, reduction_potential_tco2e,
                      investment_required, timeline_years, complexity='medium'):
        """
        Add carbon reduction initiative
        complexity: 'low', 'medium', 'high'
        """
        # Calculate abatement cost ($ per tCO2e reduced)
        annual_reduction = reduction_potential_tco2e
        abatement_cost = investment_required / (annual_reduction * timeline_years) if annual_reduction > 0 else float('inf')
        self.reduction_initiatives.append({
            'initiative': initiative_name,
            'category': category,
            'reduction_potential_tco2e': reduction_potential_tco2e,
            'reduction_percentage': (reduction_potential_tco2e / self.baseline_emissions) * 100,
            'investment_required': investment_required,
            'timeline_years': timeline_years,
            'complexity': complexity,
            'abatement_cost_per_tco2e': round(abatement_cost, 2)
        })
    def prioritize_initiatives(self):
        """Prioritize initiatives using cost-benefit analysis"""
        df = pd.DataFrame(self.reduction_initiatives)
        # Score each initiative
        # Lower cost, higher reduction, lower complexity = higher score
        # Normalize metrics (0-100 scale)
        if len(df) > 0:
            df['cost_score'] = 100 - (
                (df['abatement_cost_per_tco2e'] - df['abatement_cost_per_tco2e'].min()) /
                (df['abatement_cost_per_tco2e'].max() - df['abatement_cost_per_tco2e'].min() + 0.01) * 100
            )
            df['impact_score'] = (
                (df['reduction_potential_tco2e'] - df['reduction_potential_tco2e'].min()) /
                (df['reduction_potential_tco2e'].max() - df['reduction_potential_tco2e'].min() + 0.01) * 100
            )
            complexity_map = {'low': 100, 'medium': 60, 'high': 30}
            df['complexity_score'] = df['complexity'].map(complexity_map)
            # Overall priority score (weighted)
            df['priority_score'] = (
                df['impact_score'] * 0.4 +
                df['cost_score'] * 0.35 +
                df['complexity_score'] * 0.25
            )
            # Classify priority
            df['priority'] = pd.cut(
                df['priority_score'],
                bins=[0, 40, 70, 100],
                labels=['Low', 'Medium', 'High']
            )
            df = df.sort_values('priority_score', ascending=False)
        return df
    def generate_reduction_roadmap(self, target_reduction_pct, budget_limit):
        """
        Generate optimal roadmap to achieve reduction target within budget
        Uses greedy algorithm to select best initiatives
        """
        df = self.prioritize_initiatives()
        # Sort by priority score
        df = df.sort_values('priority_score', ascending=False)
        target_reduction_tco2e = self.baseline_emissions * (target_reduction_pct / 100)
        selected_initiatives = []
        total_reduction = 0
        total_investment = 0
        for idx, initiative in df.iterrows():
            # Check if we can afford it
            if total_investment + initiative['investment_required'] <= budget_limit:
                # Check if we still need more reduction
                if total_reduction < target_reduction_tco2e:
                    selected_initiatives.append(initiative)
                    total_reduction += initiative['reduction_potential_tco2e']
                    total_investment += initiative['investment_required']
        achievement_pct = (total_reduction / self.baseline_emissions) * 100
        return {
            'selected_initiatives': pd.DataFrame(selected_initiatives),
            'total_reduction_tco2e': round(total_reduction, 2),
            'achievement_percentage': round(achievement_pct, 1),
            'total_investment': total_investment,
            'remaining_budget': budget_limit - total_investment,
            'gap_to_target_tco2e': round(target_reduction_tco2e - total_reduction, 2)
        }
# Example reduction planning
baseline = 10000  # tCO2e
planner = CarbonReductionPlanner(baseline)
# Add various initiatives
planner.add_initiative(
    'Switch to renewable electricity',
    category='Energy',
    reduction_potential_tco2e=2000,
    investment_required=500000,
    timeline_years=10,
    complexity='low'
)
planner.add_initiative(
    'Fleet electrification',
    category='Transportation',
    reduction_potential_tco2e=1500,
    investment_required=2000000,
    timeline_years=5,
    complexity='high'
)
planner.add_initiative(
    'Supplier engagement program',
    category='Supply Chain',
    reduction_potential_tco2e=3000,
    investment_required=200000,
    timeline_years=3,
    complexity='medium'
)
planner.add_initiative(
    'Energy efficiency improvements',
    category='Operations',
    reduction_potential_tco2e=800,
    investment_required=300000,
    timeline_years=7,
    complexity='low'
)
planner.add_initiative(
    'Modal shift to rail',
    category='Transportation',
    reduction_potential_tco2e=600,
    investment_required=150000,
    timeline_years=5,
    complexity='medium'
)
# Prioritize all initiatives
priorities = planner.prioritize_initiatives()
print("All Initiatives (Prioritized):")
print(priorities[['initiative', 'reduction_potential_tco2e', 'abatement_cost_per_tco2e', 'priority']])
# Generate roadmap
roadmap = planner.generate_reduction_roadmap(
    target_reduction_pct=40,  # 40% reduction target
    budget_limit=1500000
)
print(f"\n\nReduction Roadmap:")
print(f"Target: 40% reduction from {baseline} tCO2e")
print(f"Achieved: {roadmap['achievement_percentage']}% ({roadmap['total_reduction_tco2e']} tCO2e)")
print(f"Investment: ${roadmap['total_investment']:,.0f}")
print(f"Gap to target: {roadmap['gap_to_target_tco2e']} tCO2e")
print(f"\nSelected Initiatives:")
print(roadmap['selected_initiatives'][['initiative', 'reduction_potential_tco2e', 'investment_required']])