Question: What changes when seawater temperature changes?
About the article "Climate change", section "Orbital variations".

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Large ships usually carry evaporating plants to produce fresh water, thus reducing their reliance on shore-based supplies.
Steam ships must be able to produce high-quality distillate in order to maintain boiler-water levels.
Diesel-engined ships often utilise waste heat as an energy source for producing fresh water.
In this system, the engine-cooling water is passed through a heat exchanger, where it is cooled by concentrated seawater (brine).
Because the cooling water (which is chemically treated fresh water) is at a temperature of , it would not be possible to flash off any water vapour unless the pressure in the heat exhanger vessel was dropped.
To alleviate this problem, a brine-air ejector venturi pump is used to create a vacuum inside the vessel.
Partial evaporation is achieved, and the vapour passes through a demister before reaching the condenser section.
Seawater is pumped through the condenser section to cool the vapour sufficiently to precipitate it.
The distillate gathers in a tray, from where it is pumped to the storage tanks.
A salinometer monitors salt content and diverts the flow of distillate from the storage tanks if the salt content exceeds the alarm limit.
Sterilisation is carried out after the evaporator.
Evaporators are usually of the shell-and-tube type (known as an Atlas Plant) or of the plate type (such as the type designed by Alfa Laval).
Temperature, production and vacuum are controlled by regulating the system valves.
Seawater temperature can interfere with production, as can fluctuations in engine load.
For this reason, the evaporator is adjusted as seawater temperature changes, and shut down altogether when the ship is manoeuvring.
An alternative in some vessels, such as naval ships and passenger ships, is the use of the reverse osmosis principle for fresh-water production, instead of using evaporators. 
Incredibly strong, Hardcase is able to throw a car over 50 yards with little effort.
His leg muscles allow him to leap nearly a mile.
Nearly invulnerable to damage and changes in temperature, only extreme temperatures affect him.
When he is hurt, Hardcase can heal quickly, though the process is sped up if he drinks seawater.
His senses are enhanced, allowing him to hear and see over long distances.
Hardcase later learned that the Jumpstart effect that changed him, had effectively converted him into a nanotech being, composed of organic nanotech.
As such, Hardcase learned he had many untapped abilities, such as not needing to breathe. 
Some cholesterol derivatives (among other simple cholesteric lipids) are known to generate the liquid crystalline "cholesteric phase".
The cholesteric phase is, in fact, a chiral nematic phase, and it changes colour when its temperature changes.
This makes cholesterol derivatives useful for indicating temperature in liquid crystal display thermometers and in temperature-sensitive paints. 
Magnesium (Mg) is incorporated into the calcite shells (tests) of planktic and benthic foraminifera as a trace element.
Because the incorporation of Mg as an impurity in calcite is endothermic, more is incorporated into the growing crystal at higher temperatures.
Therefore a high Mg/Ca ratio implies a high temperature, although ecological factors may confound the signal.
Mg has a long residence time in the ocean, and so it is possible to largely ignore the effect of changes in seawater Mg/Ca on the signal.
Strontium (Sr) incorporates in coral aragonite, and it is well established that the precise Sr/Ca ratio in the coral skeleton shows an inverse correlation with the seawater temperature during its biomineralization. 
As with the isotopes of other elements, a variety of processes fractionate, or alter the relative abundance of, calcium isotopes.
The best studied of these processes is the mass-dependent fractionation of calcium isotopes that accompanies the precipitation of calcium minerals, such as calcite, aragonite and apatite, from solution.
Isotopically light calcium is preferentially incorporated into minerals, leaving the solution from which the mineral precipitated enriched in isotopically heavy calcium.
At room temperature the magnitude of this fractionation is roughly 0.25‰ (0.025%) per atomic mass unit (AMU).
Mass-dependent differences in calcium isotope composition conventionally are expressed the ratio of two isotopes (usually 44Ca/40Ca) in a sample compared to the same ratio in a standard reference material.
44Ca/40Ca varies by about 1% among common earth materials.
Calcium isotope fractionation during mineral formation has led to several applications of calcium isotopes.
In particular, the 1997 observation by Skulan and DePaolo that calcium minerals are isotopically lighter than the solutions from which the minerals precipitate is the basis of analogous applications in medicine and in paleooceanography.
In animals with skeletons mineralized with calcium the calcium isotopic composition of soft tissues reflects the relative rate of formation and dissolution of skeletal mineral.
In humans changes in the calcium isotopic composition of urine have been shown to be related to changes in bone mineral balance.
When the rate of bone formation exceeds the rate of bone resorption, soft tissue 44Ca/40Ca rises.
Soft tissue 44Ca/40Ca falls when bone resorption exceeds bone formation.
Because of this relationship, calcium isotopic measurements of urine or blood may be useful in the early detection of metabolic bone diseases like osteoporosis.
A similar system exists in the ocean, where seawater 44Ca/40Ca tends to rise when the rate of removal of Ca2+ from seawater by mineral precipitation exceeds the input of new calcium into the ocean, and fall when calcium input exceeds mineral precipitation.
It follows that rising 44Ca/40Ca corresponds to falling seawater Ca2+ concentration, and falling 44Ca/40Ca corresponds to rising seawater Ca2+ concentration.
In 1997 Skulan and DePaolo presented the first evidence of change in seawater 44Ca/40Ca over geologic time, along with a theoretical explanation of these changes.
More recent papers have confirmed this observation, demonstrating that seawater Ca2+ concentration is not constant, and that the ocean probably never is in “steady state” with respect to its calcium input and output.
This has important climatological implications, as the marine calcium cycle is closely tied to the carbon cycle (see below).