Climatic impact of galactic cosmic rays

Ascertain whether galactic cosmic rays (GCRs) produce long-term climatic effects on Earth by quantifying their mechanisms and magnitudes under realistic heliospheric modulation.

Background

GCRs penetrate to the lower stratosphere and surface, ionize molecules, and can modify atmospheric chemistry, yet their fluxes are generally low compared to solar/stellar energetic particles.

Clarifying any long-term climatic role of GCRs is relevant to interpreting terrestrial climate records and extrapolating to exoplanet climates within diverse astrospheric conditions.

References

However, their fluxes are too low to pose a serious hazard to life, and whether they produce any long-term effects on Earth's climate remains unclear (Gronoff et al., 2020; Airapetian et al., 2016, 2020).

— The Exospace Weather Frontier  (2511.02871 - Loyd et al., 4 Nov 2025) in Section 2.1