Two
decades of cool weather, followed by almost 2 decades of warm weather.
Not exact matches
has been the recommendation for
decades, not just in hot
weather, where the loss
of fluid is great, but during long events with
cool or even cold temperatures.
In fact, it is very hard to measure
weather consistently over
decades and centuries, and the presence
of sites reporting
cooling is a symptom
of the noise and local variations that can creep in.
However widely the
weather varies from place to place and time to time, when meteorologists take an average
of temperatures around the globe they find that the atmosphere has been growing gradually
cooler for the past three
decades.
During the 1960s,
weather experts found that over the past couple
of decades the trend had shifted to
cooling.
Noting that the Southern Hemisphere was mostly ocean, which would tend to take up heat and delay the rise
of atmospheric temperature in the region, they had warned that people «may still be misled... in the
decade A.D. 2000 - 2010» by
cool weather there.