Carbon 14 dating simplified
I was cleaning my garden pond at the end of October and came across a live tadpole.I had previously suspected that some tadpoles are late undergoing metamorphosis, but this one really missed the boat.Natural processes absorb the equivalent of all natural emissions plus about 57% of man-made emissions, leaving an additional 16 billion metric tons of CO2 in the atmosphere each year. † In permafrost regions, perennial snow accumulations trap air bubbles that leave records of past airborne CO2 concentrations,   and because regional CO2 concentrations vary by less than 10 parts per million over the Earth, these local records are globally representative.  * Instruments located on satellites can measure certain properties of oxygen that vary with temperature.Data from these instruments is used to calculate the average temperatures of different layers of the Earth’s atmosphere.  * The lowermost layer of the atmosphere, which is called the “lower troposphere,” ranges from ground level to about five miles (8 km) high.  According to satellite data correlated and adjusted by the National Space Science and Technology Center at the University of Alabama Huntsville, the average temperature of the lower troposphere increased by 0.60ºF (0.33ºC) between the 1980s and 2000s, mostly from 1997 to 2010: * Sources of uncertainty in satellite-derived temperatures involve variations in satellite orbits, variations in measuring instruments, and variations in the calculations used to translate raw data into temperatures.  * According to temperature measurements taken near the Earth’s surface that are correlated and adjusted by NASA’s Goddard Institute for Space Studies, the Earth’s average temperature warmed by 1.5ºF (0.8ºC) between the 1880s and 2000s, mostly during 1907–19–2014: * According to temperature measurements taken near the Earth’s surface that are correlated and adjusted by the Climatic Research Unit of the University of East Anglia in the U.
So why do humans have to be so careful and only drink clean water?
It shows a “Medieval warm period” that was warmer than the present era and a “Little Ice Age” that was cooler.
The report states that: some of the global warming since 1850 could be a recovery from the Little Ice Age rather than a direct result of human activities.
By comparing data from poorly positioned stations with other stations that are properly positioned, the study determined that the temperature irregularities in the poorly positioned stations cancel one another so that their average temperature trends are “statistically indistinguishable” from the properly positioned stations.
As of July 2015, no similar study has been conducted on a global basis. * From 1979–2014, the three temperate datasets posted above differed from one another by an annual average of 0.13ºF (0.07ºC).