Climate footprints for food
Climate Footprints for food describe how much a given food product contributes to climate change. It is usually expressed per kilogram (kg) of the food product, even if the package size is bigger or smaller than one kg. This works the same way as when emissions are declared per km for cars or nutritional values per 100 grams for food.
Most food products have a long chain of production steps behind them before they end up in a grocery store. This chain is made up of e.g. the production of agricultural input, followed by agriculture or fishing, transport, refinements, and additional transport. The chain may be long and complicated. To calculate a climate footprint in a fair and representative way, all substantial emissions along the chain need to be included. To make climate footprints for different products comparable with each other, it is important that the calculations are made as similar as possible.
The phrase Life Cycle is commonly, and somewhat erroneously, used when talking about climate footprints. A life cycle contains the entire production chain, as well as the usage phase and disposal phase of the product. It is, however, only the production phase that is referred to when talking about the food life cycle, because the usage phase is when the food is in our bodies, and the disposal phase is after the food leaves our bodies and it enters the sewage systems. There are, of course, emissions associated with these latter phases, but they are rarely attributed to individual food items.
CarbonCloud hence calculates emissions from the cradle to the gate. The cradle is the production of agricultural inputs and the gate is a shelf in your typical grocery store. All substantial and relevant steps and processes that cause greenhouse gas emissions are represented in this model. This approach ensures that all food products are calculated in the same way, and can be fairly compared to each other.
It is essential to make these types of calculations with massive amounts of data. Long-running scientific endeavors, combined with national statistics, ensure that we have a sufficient base to make representative calculations for the conditions in different countries. To make the calculations as accurate as they can be, we combine this data with precise data from our customers. This allows us to quickly make calculations that are specific, such as pasta from a given company, or more generic, such as average pasta produced in Germany.
Comparing climate footprints between products
CarbonCloud is at the scientific frontier of climate footprint calculations for food and has numerous advantages compared to other methods. The climate footprint for food is most commonly calculated using Life Cycle Assessments (LCA). An LCA is typically performed by a consultant who follows a standardized method to analyze the product’s different steps along the production chain. Albeit standardized, there are three aspects that frequently make it fallacious to compare LCA results between products and studies. These three aspects are allocation, system boundaries, and the treatment of energy systems. Different choices can be made for all these in an LCA while still adhering to the standards. In CarbonCloud, all these three aspects are consistently treated the same way for all calculations, which makes CarbonCloud results for different products comparable with each other.
Allocation treats how the responsibility for emissions is distributed between different products. This is primarily a problem when one process produces more than one product.
Probably the most obvious example is a dairy cow, who produces milk, calves, meat, and leather. Throughout her life, the animal causes a quantity of greenhouse gas emissions. At the same time, she produces a number of calves, a quantity of milk, and finally—after slaughter—she produces meat and leather. The meat also consists of, more or less, expensive cuts. There is no single objective truth for how her emissions should be allocated between the products she has produced throughout her life, but different allocations can be argued to answer different questions. This is the reason why comparisons between different LCA studies can be misleading. All allocations are always treated the same in CarbonCloud.
System boundaries refer to where the line is drawn regarding which emissions to include in the calculations. The fuel for the tractor is e.g. always included, but should the production of the tractor be included or not? Are emissions for transport and distribution included? CarbonCloud treats system boundaries consistently.
Energy is required to produce food. However, it is not obvious how to treat emissions from the energy system. This is particularly true for electricity. How large the climate footprint is per kWh of electricity differs significantly among geographical locations and overtime periods, i.e. time of the year and times in the day. The Swedish electricity system is almost carbon dioxide-free, but Denmark and Germany use significant shares of coal-based power. Companies sometimes purchase green electricity; how should that be treated in the calculations? CarbonCloud has data on electricity production for different regions and countries and consistently treats electricity the same for all products.
Adding different greenhouse gases together
There is an exchange rate for greenhouse gases that allows us to compare emissions of different gases to each other. This exchange rate quantifies how many kg of CO2 a given emission of another gas is equivalent to, from a climate change perspective. This exchange rate is called Global Warming Potential and is abbreviated GWP. The unit for these emissions is kilogram carbon dioxide equivalents (kg CO2e). This means that an activity has caused emissions of different greenhouse gases that, when combined, affect the climate equally to a given amount of carbon dioxide emissions would, during a timeframe of 100 years.
There are many different greenhouse gases and carbon dioxide (CO2) is the most widely known. Different greenhouse gases impact the climate in slightly different ways. Some stay in the atmosphere for a long time, and some stay for a shorter time. Some cause more warming per molecule in the atmosphere than others.