Ancient Japanese climate records and dendrochronology reveal systemic solar-terrestrial risks to modern infrastructure

Indigenous knowledge systems, such as those of the Navajo or Māori, historically interpreted solar phenomena through cultural frameworks that emphasised reciprocity with celestial forces, often as omens or messages. These traditions were systematically suppressed during colonial expansion, erasing long-term observational records of solar variability. Reintegrating such knowledge could provide qualitative insights into solar-terrestrial relationships that quantitative models overlook.

The Maunder Minimum (1645–1715) coincided with the Little Ice Age, demonstrating how prolonged solar minima can disrupt global climate systems, as evidenced by Japanese tree-ring data and European grain shortages. Medieval Japanese poetry (e.g., *waka*) often described auroras as harbingers of famine or political unrest, reflecting empirical observations of solar-terrestrial linkages. These historical precedents challenge the modern assumption that solar activity is a static, predictable phenomenon.

Cross-culturally, solar events were rarely isolated phenomena; in Hindu traditions, solar eclipses (*Surya Grahan*) were seen as cosmic rebalancing acts requiring ritual precautions, while Islamic astronomers like Ibn al-Shatir developed sophisticated instruments to track solar cycles. These diverse approaches highlight the need for a pluralistic, globally inclusive framework for space weather research, rather than a Eurocentric one.

Tree-ring records (dendrochronology) and ice cores provide proxy data for solar activity via cosmogenic isotopes like beryllium-10, while medieval Japanese poetry offers qualitative timestamps for auroral events. Modern space weather science relies on satellite data, but these historical archives extend the temporal baseline for understanding solar cycle variability. However, the integration of humanistic and scientific data remains underutilised in risk assessment models.

Artistic and spiritual traditions often framed solar phenomena as living entities—e.g., the Māori sun god *Tama-nui-te-rā* or the Norse *Sól* chariot—imbuing cosmic events with moral and ecological significance. These perspectives framed solar activity as part of a larger, interconnected system, contrasting with the modern reductionist view of space weather as a purely physical threat. Reconnecting with such worldviews could inspire more holistic resilience strategies.

Future scenarios must account for the compounding risks of solar storms disrupting GPS-dependent logistics, undersea cables, and power grids, particularly in the Global South where infrastructure is least resilient. Climate change may amplify these risks by altering atmospheric conductivity, creating feedback loops not yet incorporated into predictive models. Scenario planning should include 'black swan' events, such as a Carrington-level event, to stress-test global systems.

Marginalised communities in Africa, South Asia, and Latin America bear disproportionate risks from space weather due to limited early-warning systems and reliance on vulnerable infrastructure. Indigenous groups with deep ecological knowledge are often excluded from disaster preparedness planning, despite their historical resilience to environmental shocks. Amplifying these voices could reveal adaptive strategies overlooked by top-down technological solutions.