Shown in the nearby graph is the measured annual temperature of the earth since 1989, just before the first report of the Intergovernmental Panel on Climate Change (IPCC).

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Until the 1940s, for example, ships typically measured the sea's temperature by dunking a thermometer into a bucket of sea water.

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It is also commonplace for the temperature in core holes to be measured.

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During the swims, the researchers measured the volunteers' oxygen consumption, rectal temperature, swim speed and angle, and stroke rate and length.

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Essentially, he says that a dramatic temperature peak will be reached in years measured in high tens to low hundreds, and that the cooling period following will take anywhere from 100, 000 to 500, 000 years, depending on what we humans do right now and in the next decade about carbon emissions.

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Before Argo, the temperature and salinity of the subsurface oceans could only be measured from ships or fixed point moorings.

UNESCO: World Water Assessment Programme (WWAP)