It was the first open-river swim there in nearly a century, the result of decades of work addressing pollution. By Leigh GiangrecoMore than 250 swimmers jumped into the Chicago River on Sunday morning, marking the first open-river swim in the once-polluted urban waterway in nearly a century.
Observations from the Little Bunker
Last updated: October 16, 2025 02:57 AM
Atmospheric CO₂
424.4 ppm
+18.2
ppm/year
Atmospheric CH₄
1933.54 ppb
+12.29
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year