How emissions with an adverse effect on the climate can be prevented
There are various ways of achieving zero emissions. The key issue here is to decarbonise production processes, i.e. avoid generating CO2 during production.Technical processes that require heat, for example, can use climate-friendly alternative fuels in the future, such as hydrogen or electricity generated by renewable resources, instead of carbonaceous ones such as oil, coal or natural gas.
Some industrial processes – such as aluminium production for instance – do not yet work without carbon as an auxiliary raw material. In this case, new production processes need to be developed where carbon no longer plays a role. This is the only way to avoid generating more CO2.
In processes where it is not possible to avoid carbon, there is another solution: instead of relying on fossil carbon sources, alternative sustainable sources of carbon such as sustainable biomass, residual material and recycled material can be used. This process is also known as defossilisation. To ensure the global carbon cycle is kept in balance, a production process should only generate as much CO2 as can be taken in by the Earth’s plants and oceans in a natural way in the same time period.
This closed global carbon cycle does not work with fossil carbon sources such as coal, natural gas or oil: they have formed over millions of years – long before human life was possible on the planet – and have stored up huge quantities of carbon in the process. By using and burning fossil fuels, this carbon is released again at a speed that never existed before. This carbon released in the form of CO2 can only be slowly transformed into biomass or even future fossil resources and therefore carries on concentrating in the atmosphere – resulting in global warming.
In many processes, however, it is not possible to avoid emitting CO2 entirely;for example, the raw material limestone itself releases CO2 during the burning process during cement production. In these cases, a way of handling the CO2 that is generated needs to be found. The important thing is to prevent the CO2 being released into the atmosphere. This means that CO2 separation technology must be incorporated into the plants where the CO2 originates. The CO2 that is captured is then taken to a location where it can be further utilised. Alternatively, it is taken to geological sites where it is stored for the long term.