Join us
Orange welcome sign that reads Royal Geographical Society with IBG.

Become a member and discover where geography can take you.

Join us

Researchers from the University of Sheffield, part of the IntCal Working Group, have conducted key research into radiocarbon calibration data to allow them to be converted into calendar years. The resulting IntCal calibration curve has international reach as the global standard for radiocarbon calibration, being used by all major commercial 14C laboratories.



Radiocarbon (14C) is the most frequently used approach to dating organic material and artefacts from the last 55,000 years. However, all radiocarbon dating requires calibration to transform 14C measurements into calendar ages.



The IntCal Working Group (IWG) is an international team of 27 scientists formed in 2001 to establish criteria for calibration data and methods to construct curves for conversion.

The key research that gave rise to the impact was undertaken at the University of Sheffield between 2001 and 2014.

Research developed a fully probabilistic modelling framework for estimating radiocarbon calibration curves, as well as a suite of Bayesian implementation methods that can be extended as new data structures become available.



IntCal curves are the internationally agreed standard for radiocarbon calibration. Currently there are at least 141 laboratories around the world with facilities for radiocarbon dating, all of which use IntCal13, SHCal13, and Marine13 calibrations. The ability to obtain accurate and precise dating is fundamental, as it informs many of the economic and professional decisions relating to the protection, conservation, and understanding of the historic environment.

A precise understanding of our past climate is needed to understand, predict, and mitigate potential, current, and future changes. As just one example, 80 of the publications cited in the Intergovernmental Panel on Climate Change (IPCC) 2013 assessment relied on the IntCal curves for their calendar dates.

The IWG have increased public awareness of the historic environment for example in the heritage sector. Radiocarbon dating has provided insights into the construction of Stonehenge, UK, as well as the earliest water-management site in Liangzhu City, China. This increased awareness facilitates a rise in the level of the protection and conservation given to heritage properties.


More information

Institution: University of Sheffield 

Researcher: Professor Caitlin E Buck 


Share this resource

This is an open access article under the terms of the Creative Commons Attribution License (CC BY NC 4.0), which permits use, adaptation, distribution and reproduction in any medium or format, provided the original work is cited and it is for non-commercial purposes. Please contact us for other uses.

How to cite

Royal Geographical Society (with IBG) (2023) Transforming time: understanding climate change and human history using IntCal radiocarbon calibration. Available at  Last accessed on: <date>