The observational record of deep - ocean variability is short, which makes it difficult to attribute the recent rise
in deep ocean temperatures to anthropogenic forcing.
The paper discusses reconstructions of
global deep ocean temperature, sea level, surface temperature, and climate sensitivity going back thousands to millions of years.
Red curve: estimated global surface air temperature change based
on deep ocean temperatures and assumption that LGM - Holocene surface temperature change is 4.5 °C.
More succinctly,
if deep ocean temperatures can naturally rise by 1 °C in 100 years without any change in CO2, then attributing changes in ocean temperature that are already «below the detection limit» for the last 200 years (or just ~ 0.1 °C since 1955) to anthropogenic CO2 forcing is highly presumptuous at best.
In addition, measurements of
deep ocean temperature rises, which enable estimates of how fast heat and carbon dioxide are removed from the atmosphere and transferred to the ocean depths, imply lower transfer rates than previously estimated.
Our modern day reef - building corals first evolved in exceedingly warm and stable climates
when deep ocean temperatures were 10 °C higher than today and palm trees dotted the Antarctic coast.
I get notified daily of most of the new papers relating to climate matters (as a retired modeller — I still retain an interest), I have seen several recently
regarding deep ocean temperature measurement and equipment that is used at multi depths.
while scientists Douglass and Knox (2014) identify the source of
modern deep ocean temperature forcing that has an «unquestionably solar origin» manifested by El Niño / La Niña phenomena.
This means it will take centuries to millennia
for deep ocean temperatures to warm in response to today's surface conditions, and at least as long for ocean warming to reverse after atmospheric greenhouse gas concentrations decrease (virtually certain).
Stott et al. (2007), for example, conclude that
deep ocean temperatures rose by 2 °C within a 2,000 - year time span (19,000 to 17,000 years ago) about a 1,000 years before CO2 concentrations (and surface temperatures) began to rise.
Deep ocean temperature might also be worth measuring very carefully.
Phrases with «deep ocean temperature»