The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human activities. In 2023, the sea surface temperature (SST) and upper 2000 m ocean heat content (OHC) reached record highs. The 0-2000 m OHC in 2023 exceeded that of 2022 by 15 +/- 10 ZJ (1 Zetta Joules = 10(21) Joules) (updated IAP/CAS data); 9 +/- 5 ZJ (NCEI/NOAA data). The Tropical Atlantic Ocean, the Mediterranean Sea, and southern oceans recorded their highest OHC observed since the 1950s. Associated with the onset of a strong El Nino, the global SST reached its record high in 2023 with an annual mean of similar to 0.23 degrees C higher than 2022 and an astounding > 0.3 degrees C above 2022 values for the second half of 2023. The density stratification and spatial temperature inhomogeneity indexes reached their highest values in 2023.