Hamburg’s carbon footprint is at the heart of a political process that extends far beyond a single project. For years, the city improved its CO₂ figures using carbon offsetting and emission certificates from Africa, even though the furnaces financed for this purpose did not exist in those countries. While measurable savings were reported on paper, the promised infrastructure was lacking in Nigeria. It is precisely this discrepancy between accounting and reality that is now forcing Hamburg to fundamentally change course. (welt: 18.12.25)
Hamburg’s Carbon Footprint and the Questionable Logic of Offsetting
To achieve ambitious climate goals, Hamburg long relied on offsetting emissions through projects abroad. Through the organization Atmosfair, the city financed a climate protection project in Africa that promised efficient cookstoves in Nigeria and India. Reduced wood consumption was intended to lower emissions there, while Hamburg credited the emission certificates to its carbon footprint. Formally, the city thus met its targets, but the actual impact remained unclear.
Between 2018 and 2020, Hamburg purchased certificates worth more than one million euros. This resulted in the city recording savings of approximately 75,000 tons of CO₂. Politically, this was considered a success, and the Senate also pointed to its role in sustainable development aid. At the same time, the environmental authority emphasized that it had used only verified emission certificates. As a result, Hamburg’s CO₂ balance appeared stable, even though it was heavily dependent on external credits.
Emission certificates without visible measures
However, the situation on the ground was different. In Nigerian regions where modern stoves were supposed to have been installed, open fires still dominated. New stoves were lacking. Nevertheless, the calculated savings were included in Hamburg’s climate balance because the contract stipulated only a reduction in emissions, not a specific number of stoves. The environmental authority referred to ex-post verified emission certificates that had been confirmed by UN bodies.
The Hamburg Court of Auditors, however, determined that no additional stoves had been installed during the relevant period. An audit report strongly criticized the project’s implementation. Atmosfair later explained that the certificates originated from already manufactured plants. Hamburg’s funding only enabled the construction of new furnaces after the fact. Thus, the CO₂ compensation was not based on measures directly triggered by Hamburg funds.
Hamburg Court of Auditors Reveals Structural Deficiencies
The Hamburg Court of Auditors’ criticism went far beyond individual issues. It criticized the lack of documentation regarding the use of funds, inadequate oversight, and unclear responsibilities. The project was also awarded without a public tender. A legal basis was lacking. Nevertheless, contracts were signed and not published. The State Court of Auditors spoke of significant violations of applicable administrative regulations.
Furthermore, it remained unclear why the number of announced furnaces changed several times. Initially, 12,000 were mentioned, later 15,000. Whether the climate protection project in Africa was expanded to compensate for lower savings could not be determined. The parallel project planned in India also failed completely, which is why additional emission allowances from Nigeria were credited.
Political Consequences for Hamburg’s Climate Balance
The debate gained political traction because the emissions reductions took place thousands of kilometers away. Hamburg was able to reduce its own efforts, while its carbon footprint appeared better on paper. Critics called it modern-day indulgences. Without the audits conducted by the Hamburg Court of Auditors, the matter would likely not have come to light.
Environment Senator Katharina Fegebank ultimately drew consequences. “I have decided that, within the framework of offsetting CO₂ emissions from air travel, the Free and Hanseatic City of Hamburg will in future only support additional climate protection projects within Hamburg.” With this decision, the city is ending CO₂ offsetting through international projects. Hamburg’s carbon footprint will henceforth be based on verifiable local measures.
Local Climate Protection Instead of International Booking Tricks
A first step has already been taken. Funds from the previous CO₂ offsetting program have been invested in additional tree planting within Hamburg. The focus is now on direct benefits, clear monitoring, and measurable impact. Experience from the African project shows how vulnerable complex structures with emissions certificates are. For Hamburg’s climate footprint, this step represents a new beginning, one that aims to regain lost trust.