After eight years, the district of bamberg is again having a CO2 balance drawn up. But the results will not be 100 percent comparable with the previous study. Not like apples with pears, but "if you take a boscope and a jonathan, you have two apples, but they taste different", robert martin, climate protection officer of the district, illustrates the problem.
Because CO2 balances are based on a lot of theory and partly on different calculation methods. For example, the software used to create the balance almost a decade ago is no longer available on the market. The aim of the current call for tenders is therefore to obtain a procedure that offers as broad a standard as possible. Because the parameters used as a basis would differ from system to system. With the "bisko-method (municipal accounting standard) is believed to have become sound.
But let’s get back to the CO2 balance sheet, with which district administrator johann kalb (CSU) has laid the "foundation for a location determination and reorientation in climate protection" wants to create. By the end of the year, the balance sheet could be drawn up. According to martin, once the calculation has been started, it takes about three months. However, the result is never an exact calculation down to the last decimal place, but always only "an instantaneous reference value".
This is essentially made up of three components: electricity, thermal energy and transport. In the case of electricity and other grid-based forms of energy, the data basis is exact and the calculation relatively simple, martin explains. But it also includes a number of other examples that require the use of statistics and other parameters.
This applies above all to traffic, which accounts for a not inconsiderable proportion of CO2 emissions. Here, the calculation was based on many assumptions, but all of them had to be plausible. But the devil is often in the details. "What about electric vehicles, for example?" Do they enter the overall balance sheet via the measurable electricity consumption, or do they enter the traffic volume, from which the CO2 emissions are calculated using statistical values?? Or, for example, the question of how and where air travelers from the district of bamberg are included in the calculation. The situation is also unclear in some respects when it comes to thermal energy, which accounts for a low proportion of CO2 emissions. Who heats how much with oil, coal or wood?? Data from chimney sweeps has been very helpful here, says martin. But the district does not simply have access to this information. "And even if we knew how many plants there are and how much power they have, we still can’t deduce how much wood, coal or oil someone actually burns." But even with heat pumps and storage heaters, it is not entirely clear which energy balance they are included in.
Despite all the question marks, robert martin does not doubt the sense of a CO2 balance sheet. Even if he can state from his many years of activity as a climate protection officer: "in the beginning, there was always just talk of CO2. But people can’t see it and they can’t smell it, so in the meantime they hardly dare to use the word. And now we are again experiencing a kind of renaissance of CO2 ."