Carbon 14 is used for radio dating of organic materials
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).
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.
One of these was a series of buoys, each containing thermometers located ten feet above the water and at one foot below the water.
The largest gap between any of the datasets in any year was 0.38ºF (0.21ºC), and the smallest gap was 0ºF/C: * To reconstruct global average temperatures in the era before instrumental measurements were made on a global scale, scientists use proxies that respond to changes in climate, such as the widths of tree rings and certain elements of the geological record, to estimate temperature variations in the past.  * The Intergovernmental Panel on Climate Change (IPCC) is a scientific body established in 1988 by the United Nations and World Meteorological Organization.
Despite seeming like a relatively stable place, the Earth's surface has changed dramatically over the past 4.6 billion years.
Mountains have been built and eroded, continents and oceans have moved great distances, and the Earth has fluctuated from being extremely cold and almost completely covered with ice to being very warm and ice-free.
Where do nature's building blocks, called the elements, come from? Her job is to figure out how much gold is in them there rocks. I don't see any more rocks in here, but the bad news is, I don't see any gold in here, either. Final steps: cool and clean the bars, stamp them with their unique serial numbers and their weights. The ancients first learned how to heat rocks to extract copper, at least 7,000 years ago. Traders in New York, London and Shanghai buy and sell more than 20 million tons a year. Copper has been prized for millennia for its unique properties: it conducts electricity better than any metal except silver; it's malleable and has a moderate melting temperature; it even scares away bacteria. Even with all the other modern materials available, they still choose bronze. Hasn't something better come along, after all these years? The quality of the sound depends on the atomic structure of the material.
They're the hidden ingredients of everything in our world, from the carbon in our bodies to the metals in our smartphones. The good news is that we haven't finished; there may be still gold hiding in the mix. And, today, it's one of the most widely bought and sold metals in the world. Copper is in wire, electronics and computer chips, plumbing and other building materials. These guys can trade their copper futures; I've got to unload my copper today. In pure metals, the atoms are arranged in orderly rows and columns.