I. According to the IPCC, the true manifestation of “global warming” can almost exclusively (93%) be found in the oceans. The surface air or atmospheric heat changes amount to just 1% of the “global warming” representation.
Image Source: IPCC (2013)
II. In the first 2000 meters of the global ocean, there has only been about 0.1°C of “global warming” in the last 50 or 60 years.
Image Source: Levitus et al., 2012
Image Source: ScienceDaily.com
III. Below that depth (2000 meters), the global ocean has been cooling since the 1990s.
Image Source: Wunsch and Heimbach, 2014
IV. The overall change in the global oceans during 1994-2013 has amounted to an underwhelming 0.02°C, as there were substantial regions of the global ocean that both warmed and cooled during this period.
Image Source: Wunsch, 2018
V. The changes in the global ocean temperatures for the 0-1000 meter layer during the last 200 years are so modest they are “below the detection limit”. There were far more rapid (>2°C/200 years) warming periods that occurred “naturally” during the Holocene.
Image Source: Bova et al., 2016
VI. The Rosenthal et al. (2013, 2017) claim – touted by Dr. Michael Mann – that the ocean warming during the 1955-2010 period has been the “fastest in 10,000 years” was shamefully derived by statistical malfeasance. Rosenthal and co-authors directly compared an 8,000-year overall trend to a 55-year anomaly. Of course temperature is more variable in decadal- rather than millennial-scaling. The modern rate of change is comparably smaller than most of the last 10,000 years if we were to compare 55-year intervals to 55-year intervals.
Image Source(s): Rosenthal et al., 2013, 2017; Climate Audit
VII. Even if we were to consider global surface temperature changes, the modern warmth is merely a partial return to the overall climate “normal” of the last two millennia. The only remarkable aspect of climatic changes in recent centuries has been the anomalous cooling that occurred during the Little Ice Age.
Image Source: PAGES 2k 2015
VIII. Finally, hemispheric-scale warming of 4-5°C within a span of a few decades – and global sea level rise amounting to 5 meters per century have occurred naturally, or without any changes in atmospheric CO2 concentration. This is the backdrop of natural variability against which the negligible modern temperature changes of 0.05°C per decade and 0.14 of a meter of sea level rise per century must be weighed when considering just how remarkable modern change has been.
And, simply put, there is nothing even remotely remarkable about the recent decades of global warming.
Image Source: Ivanovic et al., 2017