Climate scientists and the Intergovernmental Panel on Climate Change have retired the RCP 8.5 emissions scenario as an implausible projection for future warming [1, 2].
This shift alters how researchers model the most extreme potential outcomes of global warming. By removing the most apocalyptic forecasts, scientists aim to align climate projections with observed data and realistic future pathways to ensure policy decisions are based on probable outcomes [1, 2].
The RCP 8.5 scenario was previously used to represent a high-emissions future. However, new evidence shows the emissions trajectory assumed in that model is far higher than current observed trends [1, 2]. This discrepancy has led researchers to conclude that the scenario is no longer a believable representation of where the world is heading [3].
While the worst-case scenario is being dropped, the broader risk of significant warming persists. There is a discrepancy among reports regarding the scope of these changes. One report indicates that scientists are jettisoning both their worst and best-case scenarios [2], while another states that the best-case pathway remains in use while only the most apocalyptic forecasts have been removed [1].
Despite the removal of RCP 8.5, climate scientists continue to monitor global temperature rises. The transition reflects an effort to refine the accuracy of climate modeling as more real-world data becomes available, a process essential for creating effective international climate agreements.
Researchers said the decision is based on the fact that the trajectory of RCP 8.5 is simply too high to be realistic given the current global energy transition [1, 2].
“Scientists have dropped their most apocalyptic forecasts.”
The retirement of RCP 8.5 suggests that the absolute 'doomsday' projections of the past are less likely to occur due to shifts in energy trends. However, this does not signal a resolution to the climate crisis; rather, it represents a calibration of the models to ensure that the remaining scenarios provide a more accurate basis for global policy and infrastructure planning.
