Climate protectionists often warn of "tipping points", i.e. points from which, for example, the eternal ice will hardly be able to be saved. Scientists from the University of Hamburg now contradict this. They also declare the 1.5 degree target to be unrealistic.
Hamburg scientists believe that the climate target of limiting global temperature rise to 1.5 degrees above pre-industrial levels is unrealistic. "Limiting global warming to 1.5 degrees Celsius is currently not plausible," says a statement from the University of Hamburg on the "Hamburg Climate Futures Outlook 2023".
For the study presented this Wednesday, around 60 social and natural scientists in an interdisciplinary team examined ten social, climate-relevant factors. These include UN climate policy, climate protection legislation, protests, social movements, transnational initiatives, court cases, consumer behavior, the withdrawal of investments from the fossil fuel economy, knowledge production and the media.
It is said that things have started to move. But above all the behavior of consumers and companies is slowing down the climate protection that is urgently needed worldwide. "The necessary comprehensive decarbonization is simply taking place too slowly," explained the head of the Cluster of Excellence "Climate, Climate Change and Society" (CLICCS), Anita Engels. Decarbonization means the reduction of carbon dioxide emissions.
According to the authors, the media also behave ambivalently: sometimes they support the goal of a CO2-neutral society, sometimes they undermine it. Engels takes a rather positive view of professional journalism. Unlike in the USA, the media in Europe increasingly refrained from "balancing" between the majority opinion of science and "marginal" voices. "This is a very important point," said the sociologist. On the other hand, there is a lot of fake news on social media, with authors from the right-wing spectrum in particular spreading inaccurate reports.
The scientists consider the physical processes such as the loss of Arctic sea ice, the melting of the ice sheets and the regional climate changes to be serious. "But they would have little impact on the global mean temperature by 2050," it said. "There is no tipping point for the melting of the Arctic sea ice," said the director of the Max Planck Institute for Meteorology, Jochem Marotzke. Ice forms again when it gets colder.
The melting of the ice creates a darker surface, which theoretically heats up more in sunlight. However, a view of the earth from space shows that clouds often shield the sea. The feedback effect on the climate is much smaller than assumed. "The global impact (on the climate) is very small," Marotzke said.
According to the scientists, social change is crucial for curbing global warming. So far it hasn't been enough. "We're not even remotely on the right track," said Engels. The state investments to mitigate the consequences of the Corona crisis and the Russian invasion of Ukraine would have strengthened the dependence on fossil fuels. "If we miss the climate targets, it becomes all the more important to adapt to the consequences," emphasized the sociologist. Nevertheless, efforts to protect the climate must continue. Every half degree of global warming is noticeable, Marotzke warned.
But the physicist doesn't think much of "tipping points". "This term has been so softened that it is no longer suitable as a scientific term," said Marotzke, who was also a co-author of the most recent reports by the Intergovernmental Panel on Climate Change (IPCC). The development of global temperature depends on both emissions and the climate's response to them.
These feedbacks showed climate sensitivity. For example, the fear of a thawing of the permafrost is completely unfounded. A warmer Earth's atmosphere also radiates more energy into space. This effect is 40 times as strong as the climate effect of the methane that is released when the permafrost thaws.
