Proceedings of the National Academy of Sciences, Volume 122, Issue 43, October 2025. SignificanceConventional acoustic metamaterials rely on air resonance and geometrically complex, high-stiffness structures to achieve low-frequency absorption, typically leading to negligible structural deformation. These approaches are inherently …
Observations from the Little Bunker
Last updated: November 30, 2025 04:25 AM
Atmospheric CO₂
426.8 ppm
+18.1
ppm/year
Atmospheric CH₄
1927.61 ppb
+2.73
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year