You can get an idea of the relationship between C14 and age at the Carbon Dating calculator page. 1950 was chosen for no particular reason other than to honour the publication of the first radiocarbon dates calculated in December 1949 (Taylor, 19).
Ninety-five percent of the activity of Oxalic Acid from the year 1950 is equal to the measured activity of the absolute radiocarbon standard which is 1890 wood.
The study found that water temperatures increased on average by 0.23ºF (0.13ºC) per decade between 19, while air temperatures cooled by 0.02 to 0.09ºF (0.01 to 0.06ºC) per decade during the same period. examined the locations of 1,007 of the 1,221 monitoring stations used to determine average surface temperature changes across the continental United States.
The paper found that 92% of these stations are positioned in sites that can cause errors of 1.8ºF (1ºC) or more.  For example, some stations are located over asphalt (making them hotter at certain times), and others are located in partial shade (making them cooler at certain times).
[PDF] - View the entire 'Fairbanks0107' calibration curve with the option to zoom in on areas of interest.
[A Conventional Radiocarbon Age or CRA, does not take into account specific differences between the activity of different carbon reservoirs.
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).Please report bugs and send suggestions to: [email protected] “an increase in the average temperature of the Earth’s atmosphere,” either by “human industry and agriculture” or by natural causes like the Earth has “experienced numerous” times “through its history.” * Some writers use the phrases “global warming” and “climate change” to mean temperature changes strictly caused by human activity.   Other writers use adjectives such as “man-made” and “anthropogenic” to distinguish between human and non-human causes.  (“Anthropogenic” means “of human origin,” and “AGW” stands for “anthropogenic global warming.”) * Just Facts’ Standards of Credibility require the use of “language that is precise and unambiguous.” Hence, when human causes are stated or implied, this research uses terms like “man-made” and “human-induced.” * The greenhouse effect is a warming effect caused by certain gases that retain heat from sunlight. Without such gases, the average surface temperature of the Earth would be below freezing, and as explained by the , “life, as we know it, would not exist.” The global warming debate is centered upon whether added greenhouse gases released by human activity will overheat the Earth and cause harmful effects. * Human activities currently release about 37 billion metric tons of CO2 per year, which equates to about 5% of natural CO2 emissions.Implicit in the Conventional Radiocarbon Age BP is the fact that it is not adjusted for this correction.In this page, we consider natural reservoir variations and variations brought about by human interaction].The reason for this anomaly is that the limestone, which is weathered and dissolved into bicarbonate, has no radioactive carbon.