The Advisory Council on the Environment (SRU) on Wednesday published a new calculation of the amount of carbon dioxide (CO₂)., which Germany can still emit to be in line with the Paris climate targets. According to this, the amount of future emissions derived from the German Climate Protection Act comes at least close to an appropriate contribution to the global limitation of the temperature to 1.75 degrees. To do this, however, the objectives in the law would have to be complied with.
In 2021, the Intergovernmental Panel on Climate Change (IPCC) updated its estimate for the remaining global carbon budget depending on the temperature target. The SRU has now updated its previous calculation on the basis of the new IPCC figures. According to this, Germany should still emit 6.1 gigatonnes of CO₂ from 2022 if the global aim were to remain below 1.75 degrees of warming with a 67 percent probability.
With the current emissions, this budget would last for another nine years. If emissions were constantly reduced, Germany would have to become CO₂-neutral by 2040. In the old calculation, this should have happened in 2038. For a 50 percent chance of 1.5 degrees, however, only 3.1 gigatonnes of CO₂ would be left, meaning that CO₂ neutrality would have to be achieved in 2031 instead of 2032.
Converting global budgets to states is complicated
However, such calculations, which allocate IPCC budgets to individual states, are controversial; and it is also unclear how the German climate protection law fits into these figures. “There is no German CO₂ budget, only Germans who like to budget for CO₂,” says Oliver Geden from the Stiftung Wissenschaft und Politik, lead author of the current IPCC report.
As part of the Paris climate agreement, Germany has committed itself to limiting global temperature rise to well below two degrees, together with the other countries. In its reports, the Intergovernmental Panel on Climate Change gives budgets for the total amount of CO₂ that can still be emitted depending on the desired temperature target. But neither the IPCC nor the Paris Agreement gives any concrete information on how this amount should be divided between individual states.
In addition, the German climate protection law refers to all greenhouse gases, including methane and nitrous oxide, which are released particularly in agriculture. However, because these remain in the atmosphere for a much shorter time than CO₂ – in the case of methane it is only twelve years on average – there can be no overall budget for these gases: The methane emitted today is hardly relevant for the temperature at the end of the century. This is different with CO₂.
The SRU recommends the solution to the problem of distribution of simply distributing the CO₂ budget remaining immediately after the signing of the Paris Agreement among the states according to their population. This is how the Council came up with a budget for Germany, from which the emissions of the past few years had to be subtracted in order to get the remaining budget.
However, this calculation is controversial. States like Australia or the USA would have to follow this principle become CO₂-neutral in just a few yearsto stay well below two degrees is not realistic. It would be easier for such states if the current emissions were included in the calculation, which is also known as “grandfathering”. However, the SRU rejects this as unfair. “Well justifiable” are approaches that include the historical emissions and economic development rights of poorer countries; however, this would further shrink the budget for industrialized countries.
The climate targets are likely to be missed again for the time being
When comparing it with the German climate protection plans, the SRU quotes current calculations from the concept work Neue Ökonomie und a calculation by the Mercator climate research institute MCC, in which Oliver Geden was also involved. Under various assumptions, one can estimate how large the CO₂ share of the planned emissions is – currently it is almost 90 percent, significantly more than the global average. From this, the amount of CO₂ that is estimated to disappear in natural sinks such as forests or moors must be deducted. Depending on the calculation, around six to seven gigatonnes of CO₂ remain, which are likely to be emitted by 2045. This would put Germany roughly on a 1.75 degree path compared to the SRU figures.
The target years also go well together: In Germany, climate neutrality is planned by 2045, while the SRU has a temperature target of 1.75 degrees for CO₂ neutrality by 2040. However, since carbon neutrality means that remaining methane and nitrous oxide emissions are offset by removing CO₂ from the atmosphere, carbon neutrality must be achieved sooner. “I would estimate that CO₂ neutrality in the EU will be achieved five to ten years before greenhouse gas neutrality,” says Oliver Geden.
The Federal Constitutional Court also referred to the budget calculations of the SRU when it decided in a historic decision last year that the German climate plans that had been in force until then were not compatible with the fundamental rights of future generations; as a result, the Climate Protection Act was revised. It now contains annual targets for emissions from industry, the energy sector, transport, buildings, agriculture and other sources of greenhouse gases up to 2030 and overall annual reduction targets up to 2040. In 2021, however, the transport and building sectors missed their targets. Climate Minister Robert Habeck (Greens) has already admitted that not all goals will be met in 2022 and 2023 either.