A new report has found that significant social change is needed to halt catastrophic climate change — and society isn’t changing fast enough.
Keeping global warming below 1.5 degrees Celsius — the goal set in the Paris Agreement — is implausible for social reasons, not technical ones, according to the Hamburg Climate Outlook, published Wednesday. The annual publication from Germany’s University of Hamburg includes data from over 140 countries.
It is time for scientists to focus on “the question of what is not just theoretically possible, but also plausible, that is, can realistically be expected,” said Anita Engels, a professor of sociology at University of Hamburg, in a statement.
“When it comes to climate protection, some things have now been set in motion,” Engels said. While progress has been made, it has been insufficient to meet the United Nations’s climate goals set in 2015.
The researchers looked at 10 drivers of social change — including U.N. climate policy, legislation and climate protests — that could cut emissions and hold down temperatures.
These social factors are also significantly more important than the “tipping points” — such as the melting of Arctic sea ice and ice sheets or the collapse of global rainforests — that are a familiar specter haunting climate prediction. While avoiding these fearsome tipping points is essential to the sustainability of human civilization in the late 21st century, the researchers concluded, they would have limited influence on global temperatures before 2050.
Tipping points “could drastically change the conditions for life on Earth – but they’re largely irrelevant for reaching the Paris Agreement temperature goals,” said Jochem Marotzke of the Max Planck Institute for Meteorology, a co-author on the study.
Instead, Marotzke and Engels’ study found that consumption patterns and corporate responses — as well as the impact of the COVID-19 pandemic and the Russian invasion of Ukraine — slowed the elimination of carbon fuels and their replacement with zero-emission alternatives.
These findings of the University of Hamburg study reinforced another study published on Tuesday in the Proceedings of the National Academy of Sciences (PNAS).
That study — which focused on the United States — found that while there has been some progress in terms of reducing carbon emissions, the overall trajectory has not been enough to prevent dangerous levels of climate change.
In that publication, two climate scientists using machine learning concluded that the world would breach the internationally agreed-upon goal of 1.5 degrees Celsius warming by 2033 to 2035.
The results of this study are more pessimistic than previous models. They also reignite a debate on whether it’s still possible to limit global warming to the 1.5 degrees Celsius of warming set as an aspirational goal in the Paris climate agreement of 2015.
The PNAS study co-author, Stanford University’s Noah Diffenbaugh, stated that the world is on the brink of the 1.5 degrees Celsius mark in “any realistic emissions reduction scenario.”
This artificial intelligence-based study also found it unlikely that temperature increase could be kept below the more significant 2015 redline of 2 degrees Celsius warming, even with tough emissions cuts.
The algorithm determined that a high-pollution world would cross that threshold by 2050 — while a world with steep emissions cuts would delay it only until 2054.
These findings are far more pessimistic than those offered by the United Nations’s Intergovernmental Panel on Climate Change, which estimated in its 2021 report that a lower-pollution scenario would see the world pushing past 2 degrees Celsius sometime in the 2090s, according to The Associated Press.
While some agree that it’s time to stop pretending that limiting warming to 1.5 degrees Celsius is possible, others are skeptical of the pessimistic view presented by the PNAS study.
The view of these scientists was essentially in line with the University of Hamburg’s findings: that attitudes and consumption habits, not technical factors, are the main engines pushing global society down its current path toward severe climate disruption.
According to Michael Mann of the University of Pennsylvania and Bill Hare and Carl-Friedrich Schleussner of Climate Analytics, the 1.5-degree mark is still possible — if we want it to be.
Hare told The Associated Press that he believes that if the world reduces its carbon emissions by 50 percent by 2030, then the 1.5-degree mark can be achieved with only a slight overshoot, followed by further reductions.
Mann, in turn, focused on social factors. He told AP that giving up on keeping the warming below 1.5 degrees was “a self-fulfilling prophecy” and that the challenge is to limit warming as much as possible, regardless of a precise threshold like that set in the Paris Agreement.