Zipperlip, as someone with a deep personal and commercial affinity with the sea, i hope the following explanation would help fill some of the many knowledge gaps you constantly say you have. It’s from an internet page epa.gov and is by the US Environmental Protection Agency
“Increasing greenhouse gas concentrations are trapping more energy from the sun. Because changes in ocean systems occur over centuries, the oceans have not yet warmed as much as the atmosphere, even though they have absorbed more than 90 percent of the Earth’s extra heat since 1955,1,2 and even as the rate of ocean heat uptake has doubled since 1993.3
” If not for the large heat-storage capacity provided by the oceans, the atmosphere would warm more rapidly.4 Increased heat absorption also changes ocean currents because many currents are driven by differences in temperature, which cause differences in density. These currents influence climate patterns and sustain ecosystems that depend on certain temperature ranges.
”Because water expands slightly as it gets warmer, an increase in ocean heat content will also increase the volume of water in the ocean, which is one of the major causes of the observed increases in sea level (see the Sea Level indicator). For all these reasons, ocean heat content is one of the most important indicators tracking the causes and responses of a changing climate.”
