How Much Has the Earth Warmed?

The intense scrutiny that the rising temperature of the Earth’s oceans and atmosphere is receiving raises an important question, and interestingly, it doesn’t concern the current temperature, which modern science has nailed with great precision.  Rather, it’s this: What were the temperatures in the late 19th Century, when readings first took place?

As it turns out, there were various ways of taking ocean water onboard sea-going vessels that led to significantly different findings.  As a result, one group of today’s climate scientists has found the planet has warmed 1.34°C over the 1850-1900 average, whereas another found temperatures had risen 1.54°C.