For months, the 91 authors had struggled for any formulation. They had evaluated some 6,000 scientific studies, had edited 42,001 comments from science and politics - then, at the start of the second week of October, was the latest special report of the UN IPCC IPCC finished. His message: At least theoretically, humanity still has the chance to limit global warming to one and a half degrees compared to the time before the Industrial Revolution.
And that would be well worth it: For example, a few of the coral reefs in the oceans would have the chance to survive, the summer sea ice in the Arctic would remain at least partially - and so on. However, for example, the use of coal for power generation would have to be "rapidly reduced" worldwide and completely stopped by 2050, the researchers said in their report.
Recommendations for action or even instructions must not be given to the IPCC - and that's a good thing. But what exactly do the scientists' messages mean, for example, for Germany, which has been arguing for years about the future of particularly climate-damaging power generation from lignite?
"The next few years are crucial, so that our planet does not get out of balance," said Federal Environment Minister Svenja Schulze (SPD) after the publication of the IPCC Special Report. The research institute Climate Analytics from Berlin has now presented a report on how fast the German coalition exit would have to be in order to be compatible with a climate target of only one and a half degrees of warming. The basis for this are model calculations that aim to achieve global climate protection efforts at the lowest cost.
Currently, 37 percent of German gross electricity production comes from coal. According to the new study, there should be a complete phase-out by 2030. However, significant power plant shutdowns are already needed well before this time, the researchers said. "According to the path we propose in this report, around 16 gigawatt (GW) of coal power would have to be decommissioned by 2020, which would be an important step towards achieving the German 2020 emission reduction target," said Paola Yanguas Parra, head of the study.
Two different exit scenarios - both drastically
However, according to the scientists, this would also result in a tangible advantage: Germany would have a good chance of reaching its self-imposed climate target by the year 2020, which has actually long since given up. For this, it would be necessary to reduce CO2 emissions from coal-fired power plants by 42 percent compared to 2017 - or in other words: by 60 percent compared to 1990. Because so little has happened in recent years, such drastic cuts would now be made necessary.
The researchers present in their study two different variants for the exit from coal-fired power plants. One closes first the most environmentally damaging power plant blocks, the other the least economical blocks. As part of a planned and structured coal exit, the challenges of security of supply and the reliability of the power supply in both cases are manageable, the researchers said.
Researchers at the Fraunhofer Institute for Energy Economics and Energy Systems in Kassel, who had commissioned Greenpeace to calculate a scenario for a rapid carbon leakage that would make it possible to achieve the climate goals by the end of the decade, had already expressed similar views in the past. They had proposed a shutdown of 6.1 GW of power plant output with a simultaneous massive expansion of renewables by 2020.
"Worldwide relevant signal"
The current report will be published before the next coal commission meeting. She has been working since June and is to make recommendations for the specific exit scenario. The exit point, which the Commission would recommend for Germany, "will set a globally relevant signal," said Bill Hare of Climate Analytics.
The problem: "The carbon offset period until 2030 is much faster than the benchmark values that have been discussed in the coal commission by government officials as an appropriate contribution of coal-fired power generation to the German reduction targets," reads the summary of the Climate Analytics report.
IPCC author Hans-Otto Pörtner, asked about the German pace at Kohlaususstieg, recently said in an interview with SPIEGEL: "The impending loss of 20,000 jobs can not delay the national transition to sustainable business." That, according to the scientist, is his "private opinion": But the exit should not be postponed. The country is wealthy enough to financially support the necessary structural change.
What that could mean, however, has been stated by Saxony-Anhalt's Prime Minister Rainer Haseloff a few days ago: in his view, 60 billion euros would be needed for a socially acceptable coal exit.