From Watts Up With That?
The narrative surrounding Arctic sea ice has been one of consistent warning, punctuated by a series of prediction failures that have spanned decades. Scientists have long been forecasting the demise of Arctic summer ice, but their deadlines have continually passed, leaving us with a track record of failed predictions. The latest claim is no different, suggesting that it’s too late now to save Arctic summer ice. But as we’ve seen, the timeline for these forecasts can shift considerably and unpredictably.
In the recent study led by Prof Seung-Ki Min of Pohang University, South Korea, and Prof Dirk Notz, of the University of Hamburg, Germany, they assert that the Arctic will be ice-free in September in the coming decades. However, it’s worth noting that projections of this nature have been made before and subsequently revised. The once-dreaded ‘first ice-free summer’ was initially predicted to be in 2012, but then fluctuated back and forth for years. This kind of time-hopping has led to considerable skepticism and has undermined the credibility of such predictions.
The sixth assessment report of the IPCC assessed that the Arctic is projected to be on average practically ice-free in September near mid-century under intermediate and high greenhouse gas emissions scenarios, though not under low emissions scenarios, based on simulations from the latest generation Coupled Model Intercomparison Project Phase 6 (CMIP6) models. Here we show, using an attribution analysis approach, that a dominant influence of greenhouse gas increases on Arctic sea ice area is detectable in three observational datasets in all months of the year, but is on average underestimated by CMIP6 models. By scaling models’ sea ice response to greenhouse gases to best match the observed trend in an approach validated in an imperfect model test, we project an ice-free Arctic in September under all scenarios considered. These results emphasize the profound impacts of greenhouse gas emissions on the Arctic, and demonstrate the importance of planning for and adapting to a seasonally ice-free Arctic in the near future.https://www.nature.com/articles/s41467-023-38511-8
The key takeaway here is that these are projections, models based on certain conditions and parameters. The crux of the matter is the unpredictability of natural phenomena and the myriad factors influencing them.
The new study claims that 90% of the melting is a result of human-caused global heating, but the remaining 10% are natural factors such as variation in the sun’s intensity and emissions from volcanoes. The researchers can’t pinpoint a specific year for the first ice-free summer due to this natural variability in the climate system.
The inherent complexity of the Earth’s climate system, combined with the inability to account for every single variable that influences the melting of Arctic ice, puts these predictions on shaky ground. As has been proven repeatedly over the years, alarmist deadlines for an ice-free Arctic have come and gone, leaving us to ponder the credibility of these predictions. In the realm of science, it’s crucial to distinguish between what we know and what we assume.
Decades of failed predictions about the end of Arctic sea ice should prompt us to view these new findings with a critical eye. As we continue to study and learn about the Earth’s complex climate system, it’s essential to strike a balance between caution, skepticism, and the willingness to reassess our models and predictions.
HT/Hans Erren and strativarius