College of Engineering, CARNEGIE MELLON UNIVERSITY
For decades, climate change researchers and activists have used dramatic forecasting to influence public perception of the problem and to call for climate change. These projections often refer to events that could be described as “apocalyptic” as they predict catastrophic events as a result of climate change.
In a new article published in the International Journal of Global Warming, David Rode and Paul Fischbeck of Carnegie Mellon University argue that such predictions can be counterproductive. “Truly apocalyptic predictions can only ever be observed in their failure – that is, the world did not end as predicted,” says Rode, additional research faculty at Carnegie Mellon Electricity Industry Center, “and the observation of a number of repeated apocalyptic prediction errors can undermine public confidence in the underlying science. “
Rode and Fischbeck, professor of social and decision-making sciences as well as engineering and public order, collected 79 predictions of the climate-related apocalypse that go back to the first day of earth in 1970. Over time, many of these predictions have expired. The data has come and gone uneventfully. In fact, 48 (61%) of the forecasts expired by the end of 2020.
Fischbeck noted, “From a prognostic point of view, the ‘problem’ is not only that all of the expired predictions were wrong, but also that so many of them have never admitted any uncertainty about the date. About 43% of the forecasts in our dataset did not mention any uncertainty. “
In some cases, the forecasters were both explicit and certain. For example, Stanford University biologist Paul Ehrlich and British environmental activist Prince Charles are serially failed forecasters who repeatedly express a high level of certainty about apocalyptic climate events.
Rode commented: “Ehrlich made predictions about the collapse of the environment up to 1970, which he described as“ almost certain ”. Similarly, Prince Charles repeatedly warned of an “irretrievable collapse of the ecosystem” if no action was taken and repeated the prediction after it expired with a new final end date. Your predictions have been repeatedly apocalyptic and very certain … and so far they have been wrong. “
The researchers found that the average time horizon before a climate apocalypse for the 11 predictions made before 2000 was 22 years, while for the 68 predictions made after 2000, the average time horizon was 21 years. Despite the time, little has changed – over half a century of predictions; The apocalypse is always around 20 years old.
Fischbeck continued: “It’s like the boy who repeatedly cried wolf. If I see many consecutive forecast errors, I may not be ready to take future forecasts seriously.
That’s a problem for climate science, say Rode and Fischbeck.
“The underlying science of climate change has had many solid results,” says Fischbeck. “The problem is often the leap of combining predicting climate events with predicting the consequences of these events.” Human adaptation and mitigation efforts, as well as the complexity of socio-physical systems, mean that, for example, predicting sea level rise does not necessarily lead to apocalyptic floods.
“By linking the climate event and the possible consequence for dramatic effects,” noted Rode, “failure to observe the consequence can unfairly question the legitimacy of the science behind the climate event.”
With the new Biden government making climate policy a top priority, trust in scientific predictions about climate change is more important than ever. However, scientists need to be careful in qualifying their predictions. When measuring the proliferation of predictions using search results, the authors found that predictions that did not mention uncertainty in their apocalyptic date tended to be more visible (i.e., more search results were available). Making sensational predictions about the fate of mankind, while scientifically doubtful, has nonetheless proven enticing to those looking to make the headlines.
The problem with this is that, because of their training, scientists tend to make cautious statements and point out uncertainty more often. Rode and Fischbeck found that 81% of the predictions made by scientists were related to uncertainty, but less than half of the predictions made by non-scientists.
“That’s not surprising,” said Rode, “but it’s worrying when you consider that prognoses that reference uncertainties are less visible on the web.” As a result, the most visible voices are often the least qualified. “
Rode and Fischbeck argue that scientists need to be extremely careful when communicating significant events. When it comes to climate change, the authors advise “thinking small”. That said, we focus on making predictions that are less grandiose and short-term. “If you want people to believe big predictions, you have to first convince them that you can make small predictions,” says Rode.
Fischbeck added, “We need predictions for a wider variety of climate variables, we need to make them regularly, and we need expert assessments of their uncertainties so that people can better calibrate themselves to the forecaster’s accuracy.”