A new survey reveals a wide range of beliefs among climate experts about future global warming. While some are optimistic about staying below 2°C, most expect significantly higher temperatures by 2100. This article explores the dynamics of the climate science community and the challenges of communicating uncertain long-term projections. Climate change and global warming remain critical issues facing humanity.
Diverging Perspectives on Future Climate Impacts
The results of a recent study conducted by researchers reveal a fascinating glimpse into the dynamics of modern climate science. The study surveyed 211 authors of past reports from the Intergovernmental Panel on Climate Change (IPCC), representing all working groups and every inhabited continent. The data they shared provides insights into the wide range of beliefs held by these trusted experts.
Participants in the study were asked to share their best guesses about where the world is headed in terms of future global warming. The median estimate was 2.7°C of warming by 2100, which is roughly what is expected if the world’s nations fail to implement new policies consistent with their targets and pledges, and instead only maintain existing levels of action. This could be a catastrophic outcome for humanity, as we’ve already seen devastating consequences like more flooding, hotter heat waves, and larger wildfires at just 1.3°C above pre-industrial levels.
However, the survey also revealed that a small number of experts believe that staying below the 2°C target is still likely, while others believe we are on track for even more horrendous levels of climate warming at above 3°C. Approximately 86 percent of participants estimated warming of more than 2°C by or before the year 2100.
Perceptions of Peer Beliefs: The ‘False Consensus Effect’
A unique feature of the study is that the researchers also asked IPCC authors what they thought others in the survey would answer in response to the same questions. They were interested to know the extent to which experts in this field believed that other experts shared similar beliefs to their own.
The findings showed that participants in the study believed very strongly that their peers’ views on expected future warming were in line with their own beliefs. Even those who expected very high or very low amounts of future warming incorrectly believed that their peers would have similar estimates. This phenomenon is known as the false-consensus effect, where people tend to estimate the beliefs of their peers by examining their own beliefs and then adjusting up or down, but often insufficiently.
This finding could be problematic if an author confidently believes that their expectations are also widely shared by their peers. As trusted public figures, IPCC authors are often asked to share their thoughts with decision-makers and the media. The researchers see this study as an opportunity for experts to better understand the range of beliefs held by their own community, so they can communicate with more nuance and awareness as to whether their personal beliefs are part of a larger consensus or not.
Climate experts are not oracles, and even though a ‘wisdom of the crowd’ average is often more accurate than a single expert, forecasting decades into the future is extremely difficult. The balance of evidence from this study reaffirms a message that climate scientists have been repeating for a long time: current efforts to tackle climate change are insufficient and more progress is needed quickly.
Exploring the Nuances of Climate Projections
The researchers also explored whether IPCC authors who worked on climate solutions would be more optimistic than those who worked on climate vulnerability and adaptation. One reason for this is that experts who work on solutions might be more aware of recent research indicating that worst-case climate outcomes are becoming less likely.
However, the study only found weak evidence for this hypothesis. This is a good sign, as it suggests that researchers are not working in isolated silos, each holding their own beliefs. Instead, the findings indicate a more nuanced understanding of the complex challenges posed by climate change.
It’s important to recognize that even though the median estimate of 2.7°C of warming by 2100 is concerning, the survey results also show a range of beliefs among climate experts. Some remain optimistic about staying below the 2°C target, while others are more pessimistic about the future.
This diversity of perspectives highlights the inherent uncertainties and difficulties in making long-term projections about a complex, dynamic system like the Earth’s climate. As the researchers note, climate experts are not oracles, and even the ‘wisdom of the crowd’ average can be inaccurate when it comes to forecasting decades into the future.
Nevertheless, the overall message from this study is clear: current efforts to address climate change are insufficient, and significant additional progress is needed to mitigate the risks and impacts of global warming. Policymakers and the public must grapple with these uncertainties and work towards a more sustainable future.
