by K. Richard, Nov 5, 2020 in NoTricksZone
The forcing uncertainties and lack of observational measurements in the top-to-bottom global ocean preclude an assessment that modern warmth is due to anthropogenic activities.
Key points from a new paper (Gebbie, 2021):
• 93% of the changes to the Earth’s energy budget, manifested as warming of the Earth system, are expressed in the global ocean. Just 1% of global warming is atmospheric.
• Even with the advent of “quasi-global” temperature sampling of the ocean since 2005 (ARGO), these floats “do not measure below 2,000-m depth.” This means that temperature changes in “approximately half the ocean’s volume” are still not being measured today.
• To detect the effects of anthropogenic forcing, it would require energy budget imbalance measurement precision of 0.1 W/m² at the top of the atmosphere (TOA). Uncertainty in the forcing changes affecting climate are ±4 W/m², meaning that uncertainty is about 80 times greater than an anthropogenic signal detection.
• Past changes in global ocean heat content, such as the last deglaciation, have been 20 times larger than modern changes.
• Ocean heat storage during the Medieval Warm Period (Medieval Climate Anomaly, or MCA) was much greater than modern. Modern global ocean heat uptake is “just one-third” of what is required to reach the levels attained during Medieval times.