Spend-based carbon accounting estimates emissions based on the actual expenditure on goods and services. This method involves converting the financial amounts spent (in currencies like EUR, USD, etc.) into carbon emissions using established conversion factors. It provides an overview of emissions associated with the financial outlay on various products and services.
A manufacturing company that buys raw materials can use spend-based carbon accounting to estimate emissions by converting the dollars spent on steel into a carbon footprint. If the company spends $100,000 on steel, and the emission factor for steel is 1.5 kg CO2e per dollar spent, the estimated emissions would be 150,000 kg CO2e.
Activity-based carbon accounting calculates emissions based on specific activities or processes within a company. It involves quantifying emissions from direct measurements of activities such as kilometers driven, kilograms or liters purchased, and kilowatt-hours consumed. This method provides detailed operational insights and allows for targeted emissions reductions.
A logistics company can use activity-based carbon accounting to measure emissions from its fleet of vehicles. By tracking the kilometers driven or fuel consumed in liters, and specific vehicle type, the company can calculate emissions for each journey. If a 3.5t truck with a 100% payload drives 10,000 kilometers and consumes 5,000 liters of diesel, with a known emission factor for kgCO2e or tCO2e per liter, the emissions can be precisely calculated.
Both spend-based and activity-based carbon accounting have their place in a comprehensive carbon management strategy. While spend-based accounting offers a quick and broad overview, activity-based accounting provides the granular detail necessary for precise emissions tracking and reduction. Companies should consider their specific needs, data availability, and sustainability goals when choosing the appropriate method for an emission source.
By understanding and effectively applying these carbon accounting methods, businesses can make informed decisions that not only improve their environmental performance but also enhance their reputation and competitiveness in an increasingly eco-conscious market.