Limiting global warming to 1.5 degrees Celsius not plausible, states German research report

The interdisciplinary team of researchers addressed ten important drivers of social change.  "Actually, when it comes to climate protection, some things have now been set in motion. But if you look at the development of social processes in detail, keeping global warming under 1.5 degrees Celsius still isn't plausible," says the CLICCS Speaker Anita Engels.

According to the Hamburg Climate Futures Outlook, especially consumption patterns and corporate responses are slowing urgently needed climate protection measures.

Other key factors such as UN climate policy, legislation, climate protests and divestment from the fossil fuels are supporting efforts to meet the climate goals. However, the analysis showed this positive dynamic alone wouldn't suffice to stay within the 1.5-degrees Celsius limit.

"The deep decarbonisation required is simply progressing too slowly," Engels said.

In addition, the research team assessed certain physical processes that are frequently discussed as tipping points, such as the loss of the Arctic sea ice and melting ice sheets, which are serious developments as are regional climate changes. But they will have very little influence on the global temperature till 2050, they said. In this regard, a thawing permafrost, weakened Atlantic Meridional Overturning Circulation (AMOC), and the loss of the Amazon Forest are more important factors, albeit only moderately, the report said.

"The fact is that these feared tipping points could drastically change the conditions for life on Earth - but they're largely irrelevant for reaching the Paris Agreement temperature goals," the CLICCS Co-Speaker Jochem Marotzke from the Max Planck Institute for Meteorology, Germany, said.

The report also covered COVID-19 and the Russia-Ukraine war. Economic reconstruction programmes have reinforced dependence on fossil fuels, which means the necessary changes are now less plausible than previously assumed, the report said.

In contrast, whether efforts to safeguard Europe's power supply and the international community's attempts to become independent of Russian gas will undermine or accelerate the phasing out of fossil fuels in the long run remains unclear, the report said.

The Outlook is currently the only assessment that interlinks social sciences and natural sciences analysis in an integrated study to assess the plausibility of certain climate futures, the report said.

More than 60 experts have contributed, it added.

According to the report, the best hope for shaping a positive climate future lies in the ability of society to make fundamental changes, or "human agency".

In addition, the Outlook reveals a range of conditions for doing so, for instance that transnational initiatives and non-government actors continue to support climate protection, and that protests keep up the pressure on politicians.

"The question of what is not just theoretically possible, but also plausible, that is, can realistically be expected, offers us new points of departure," Engels said, adding, "If we fail to meet the climate goals, adapting to the impacts will become all the more important."

In this regard, the Hamburg Climate Futures Outlook introduced a new tool for testing the long-term effects of various measures, the report said.

"In order to be equipped for a warmer world, we have to anticipate changes, get the affected parties on board, and take advantage of local knowledge. Instead of just reacting, we need to begin an active transformation here and now," said Engels.