From Watts Up With That?

By Charles Rotter

The dominant narrative in climate science holds that Arctic sea ice loss is almost entirely driven by human-induced global warming, primarily from CO2 emissions. Yet, a Nature Communications study titled Role of Atmospheric Rivers in Shaping Long-Term Arctic Sea Ice Variability highlights a crucial factor that has been largely overlooked: atmospheric rivers (ARs). These ARs—narrow, intense streams of water vapor originating in tropical and mid-latitude regions—play a significant role in Arctic sea ice variability, a phenomenon that traditional climate models fail to adequately capture.

By concentrating so heavily on CO2 as the main culprit of Arctic sea ice decline, mainstream climate models ignore the complex interactions between natural atmospheric phenomena and sea ice variability. This omission exposes the significant limitations in our understanding of the Arctic’s climate, and by extension, the reliability of the climate models driving current policy.

What Are Atmospheric Rivers, and Why Are They Important?

Atmospheric rivers are immense, fast-moving channels of water vapor that can transport moisture across vast distances. These rivers are known for delivering enormous quantities of water in the form of rain or snow when they make landfall, but their influence on the Arctic is less understood. The Nature Communications study shows that ARs can have a profound impact on the Arctic’s sea ice cover, both in terms of accelerating melt and contributing to periods of ice recovery.

These atmospheric rivers inject warm, moist air into the Arctic, which increases the temperature in the region and melts sea ice. The moisture they bring also plays a significant role in cloud formation, which in turn affects the energy balance of the Arctic system. Yet, despite this, ARs are often left out of the conversation when discussing Arctic ice loss, as the focus remains firmly fixed on CO2 emissions. This begs the question: why are such natural forces so often ignored in the narrative?

Abstract

Atmospheric rivers (ARs) reaching high-latitudes in summer contribute to the majority of climatological poleward water vapor transport into the Arctic. This transport has exhibited long term changes over the past decades, which cannot be entirely explained by anthropogenic forcing according to ensemble model responses. Here, through observational analyses and model experiments in which winds are adjusted to match observations, we demonstrate that low-frequency, large-scale circulation changes in the Arctic play a decisive role in regulating AR activity and thus inducing the recent upsurge of this activity in the region. It is estimated that the trend in summertime AR activity may contribute to 36% of the increasing trend of atmospheric summer moisture over the entire Arctic since 1979 and account for over half of the humidity trends in certain areas experiencing significant recent warming, such as western Greenland, northern Europe, and eastern Siberia. This indicates that AR activity, mostly driven by strong synoptic weather systems often regarded as stochastic, may serve as a vital mechanism in regulating long term moisture variability in the Arctic.

https://www.nature.com/articles/s41467-024-49857-y

The Complexity of Arctic Sea Ice Variability

One of the most valuable contributions of this study is how it emphasizes the complexity of Arctic sea ice variability. The study documents that atmospheric rivers play a dual role in the Arctic: at times, they can melt sea ice by delivering heat, while in other instances, they help stabilize or even recover sea ice under certain conditions. This nuanced effect is vital to understanding why Arctic ice levels are not following the simplistic, linear trajectory of decline that CO2-centric climate models predict.

For example, in years with fewer or weaker atmospheric rivers, sea ice can recover, even in the context of an overall warming trend. Conversely, strong or frequent AR events can lead to accelerated ice loss. This dynamic, episodic interaction starkly contrasts with the popular portrayal of Arctic sea ice loss as an inevitable, unidirectional consequence of increasing CO2 levels. Instead, it points to a system where natural variability and short-term weather events play as significant a role as long-term climate trends.

The Limitations of Current Climate Models

The study’s findings expose significant deficiencies in the climate models that underpin much of the global warming narrative. These models, which are the foundation for policies like Net Zero and the Green New Deal, are primarily driven by the assumption that rising CO2 levels are the dominant force behind climate change. Yet, as the Nature Communications study reveals, atmospheric rivers—completely unrelated to CO2 emissions—are major drivers of Arctic sea ice variability.

Why do current climate models fail to account for such phenomena? The answer lies in the inherent limitations of these models. Climate models are built on assumptions and simplifications that struggle to accurately capture complex, chaotic atmospheric interactions like ARs. As a result, their projections tend to overestimate the impact of CO2 and underestimate or outright ignore natural variability.

This creates a problematic situation where policymakers are making decisions based on incomplete or faulty data. If atmospheric rivers, which are unpredictable and chaotic, can exert such a significant influence on the Arctic, it calls into question the reliability of long-term projections made by models that neglect them.

Natural Variability: A Long-Ignored Factor

The role of natural variability in shaping the Arctic’s climate is another critical point highlighted by the Nature Communications study. Arctic sea ice levels have fluctuated significantly in the past, long before the industrial era. Periods of Arctic warming in the early 20th century, for example, occurred with no significant rise in CO2 levels, pointing to the influence of natural climate drivers, including atmospheric rivers and oceanic cycles.

This should make us question why modern climate science tends to downplay or ignore the role of natural variability in current climate trends. The idea that CO2 is the singular driving force behind Arctic changes is not supported by historical evidence. The Arctic has always been subject to complex interactions between atmospheric and oceanic forces, and atmospheric rivers are just one example of such natural drivers.

Yet, today’s climate models tend to gloss over these complexities, focusing instead on greenhouse gas emissions as the primary explanatory variable. This not only leads to inaccurate predictions but also promotes a one-dimensional understanding of climate dynamics, particularly in the Arctic.

ARs, which can cause rapid and extreme moisture surges, may lead to significant Arctic melt events and initiate positive feedback loops. Future studies are essential to explore these potential new roles of ARs in AA as the Arctic continues to warm.

https://www.nature.com/articles/s41467-024-49857-y

Arctic Sea Ice Recovery: An Inconvenient Truth

Another inconvenient fact often omitted from the CO2-driven narrative is the occasional recovery of Arctic sea ice. While it’s true that there has been a long-term decline in sea ice, periods of recovery—such as those observed after the dramatic low in 2012—undermine the idea of a linear decline. The Nature Communications study suggests that atmospheric rivers can create conditions conducive to ice recovery, depending on their timing and intensity.

For example, a lower-than-average occurrence of ARs in certain years has allowed for the temporary recovery of Arctic sea ice. This goes against the projections of climate models that had forecast an ice-free Arctic by now. It turns out the Arctic is more resilient than many alarmist predictions would have us believe, largely because these predictions fail to consider the full range of forces—like ARs—that influence ice variability.

This raises an important point: how reliable are the models if they cannot account for the natural forces that occasionally lead to sea ice recovery? This is not just an academic question—it has serious implications for the climate policies being pursued around the world today.

Questioning Drastic Climate Policies

Given the findings of the Nature Communications study, it becomes increasingly difficult to justify the extreme climate policies being advocated by governments and international organizations. The Net Zero agenda, which seeks to eliminate all carbon emissions, is premised on the idea that human-induced CO2 is the primary driver of climate change. But if natural variability, including phenomena like atmospheric rivers, plays a significant role in climate dynamics, then the rationale for these policies becomes less clear.

This doesn’t just affect scientific debates—it has real-world consequences. The costs of achieving Net Zero, in terms of both economic disruption and environmental degradation from mining for rare earth metals for renewable technologies, may far outweigh the supposed benefits. Worse, by focusing on CO2 reduction as the sole solution, these policies ignore more practical, adaptive strategies that could better help societies cope with the impacts of climate change—whatever its causes.

The Unsettled Science of the Arctic

Ultimately, the Nature Communications study serves as a reminder that the science of the Arctic, and by extension, climate change as a whole, is far from settled. Atmospheric rivers, oceanic cycles, and other natural phenomena play significant roles in shaping the Earth’s climate, yet they are often ignored in favor of simplistic, politically convenient narratives centered around CO2 emissions.

The failure to adequately model and predict the influence of ARs on Arctic sea ice is just one example of how climate science still has much to learn. Policymakers should take heed: enacting drastic climate measures based on incomplete or inaccurate models could do more harm than good.

The lesson here is one of humility. The Earth’s climate is a complex, dynamic system with many interacting parts. By reducing it to a single variable—CO2—we risk not only misunderstanding the problem but also implementing ineffective and potentially harmful solutions.

As the Nature Communications study shows, the influence of atmospheric rivers on Arctic sea ice variability is a critical factor that cannot be ignored. It’s time we move beyond the oversimplified, CO2-centric models and embrace a broader, more nuanced understanding of the forces at play in our climate system.

Conclusion: A Call for Rethinking Climate Models and Policies

The study on atmospheric rivers has given us a valuable insight into the complexity of Arctic sea ice variability. The role of ARs in both ice melt and recovery provides a clear challenge to the simplistic view that Arctic changes are primarily driven by CO2 levels. This should prompt us to rethink the way we approach climate science and, more importantly, climate policy.

By acknowledging the limitations of current models and embracing a more holistic understanding of climate dynamics, we can develop more effective, adaptive strategies that better serve both the environment and humanity. The Arctic’s fate is not as straightforward as many would have us believe, and neither should be the policies we enact in response to its changes.

---