Freshwater forcing due to melting Arctic ice is identified as a mechanism causing reductions of the Atlantic Meridional Overturning Circulation (AMOC). This paper published shows a muted AMOC response to freshwater forcing in the early-to-middle Holocene 11,700 to 6,000 years ago. This study demonstrates that the AMOC is not as sensitive to Arctic freshening as is currently projected for the end of the twenty-first century. Incorporating this result in climate models would increase the AMOC’s cooling effect and reduce temperature projections.

Richard Willoughby published a paper that analyses the role of atmospheric water in regulating Earth’s thermal balance. The paper shows the actual temperature limiting process using hourly data observed at moored buoys in three tropical oceans. Open ocean surface temperature is observed to be limited to below 32 °C and annual average for the warmest open ocean water is 30 °C. The mechanism of deep convection results in the persistency of clouds over ocean warm pools preventing further heat uptake once the sea surface reaches 32 °C. The global ocean energy balance is examined and it is shown that atmospheric water is a net cooling agent. When the total atmospheric water in a column reaches the equivalent of 45 mm of liquid water, the atmospheric water becomes a net cooling agent with reduction in surface insolation due to cloud reflection being greater than the reduction in outgoing longwave radiation due to the low radiating temperature of high-altitude cloud. Current climate models falsely assume the oceans keep absorbing heat through the surface without end.

A new study (Long et al 2022) found the corals thrived when the climate was warmer than today. The authors reconstructed the development of coral reefs located in the northern border of the tropics from drilling cores. The abstract says “The correlation between coral reef vertical accretion rate and its climate background suggests that the rapid development stage of coral reefs on the Weizhou Island could roughly correlated to the Late Megathermal Period, Roman Warm Period and Current Warm Period and the slowing down stages of development of reefs roughly corresponded to the cold periods." As summarized here, sea levels were 2 m higher than they are today ~4,000 years ago, and still about 1 m higher than today 1,000 years ago, or during the Medieval Warm Period. The South China Sea surface temperatures were “3 to 6°C higher than today” from about 5,000 to 4,000 years ago; coral reefs developed rapidly in that warmth.

Ten years ago a paper predicted that within ten years the coral of the Great Barrier Reef (GBR) of Australia would decline to only 5-10% of its original cover. This didn’t happen. According to Peter Ridd, a marine geophysicist who has studied the GBR for over 35 years, the GBR is in absolutely fabulous condition. Some coral scientists claimed that climate change has caused catastrophic reef damage three times in the past five years. Ridd says “That damage could never have been as dramatic as they claimed: someone has been exaggerating a lot here, because dramatic damage and already such a spectacular recovery, that is simply not possible.” A long-term monitoring of the reef, conducted by the Australian Institute of Marine Science, shows that the reef was in top condition in 2020-2021. The coral cover is now three times higher than in 2012.

This study of the corals on Turks and Caicos Islands in the Caribbean from 2012 to 2018 found that 35 key coral species remained resilient during a 2017 global coral-bleaching event. The study found that corals that experienced bleaching quickly recovered. The lead author said "Boulder-type corals on the Turks and Caicos Islands demonstrated no significant bleaching as a result of the peak thermal stress in late 2015, Plate-type corals did suffer bleaching, but they quickly rebounded. Their pigmentation levels were back to normal within months of the anomalously high thermal stress."

Earth's climate cooled considerably across the transition from the Medieval Warm Period to the Little Ice Age about 700 years ago. Theoretically, owing to how the ocean circulates, this cooling should be recorded in Pacific deep-ocean temperatures, where water that was on the surface then is found today. Gebbie and Huybers used an ocean circulation model and observations from both the end of the 19th century and the end of the 20th century to detect and quantify this trend. The ongoing deep Pacific is cooling, which revises Earth's overall heat budget since 1750 downward by 35%.