Correcting an Error in Some Interpretations of Atmospheric &amp;lt;sup&amp;gt;14&amp;lt;/sup&amp;gt;C Data

David Evans Andrews

doi:10.11648/j.earth.20200904.12

Abstract

The variable “∆14C”, commonly used in radiocarbon dating and tracing applications to quantify 14C levels, is a measure of the ratio of the radioisotope 14C to other carbon in a sample. After atmospheric nuclear testing in the 1950’s and 1960’s nearly doubled atmospheric 14C, the later evolution of ∆14C allowed insights into the dynamics of carbon exchange between the atmosphere and terrestrial and marine sinks. But a few authors without backgrounds in isotope measurements have confused ∆14C with excess 14C concentration. They erroneously interpret the present recovery of ∆14C to near its pre bomb test value as evidence that atmospheric 14C concentration has returned to its earlier value. From this they reach further incorrect conclusions about the fate of anthropogenic CO2 introduced into the atmosphere by fossil fuel burning. An estimate of the true time dependence of atmospheric 14C concentration over the past century, calculated from averaged atmospheric ∆14C and CO2 data is presented. The data show that 14C concentrations remain over 30% above 1950 values, and have begun to increase, even as ∆14C continues to fall. This confirms the prediction of a conventional model of the carbon cycle. The unconventional models of carbon dynamics motivated by the mistake, on the other hand, are excluded by the properly interpreted 14C data.

Highlights

A broad consensus of both climate scientists and the public accepts that human activities such as burning fossil fuels are responsible for the worrisome increase in atmospheric CO2 over the last century
The success of radiocarbon dating is predicated on an at least approximately stable abundance ratio between 14C and the other carbon isotopes in the natural environment for tens of thousands of years. (See for example [7]) Natural 14C is produced in the upper atmosphere from cosmic ray generated neutrons interacting with nitrogen. 14CO2 is formed and distributed throughout the biosphere
They reasoned that anthropogenic carbon from fossil fuel burning would behave and concluded that human activity was not a major contributor to increasing atmospheric CO2

Summary

Introduction

A broad consensus of both climate scientists and the public accepts that human activities such as burning fossil fuels are responsible for the worrisome increase in atmospheric CO2 over the last century. A few continue to argue that the increase is “natural” and outside of human control [1,2,3,4]. While extensive rebuttals of these arguments have been made elsewhere [5, 6], the common motivating factor for the maverick papers appears not to have been identified before now: all make the same mistake in interpreting 14C data collected and presented by others. In this note we will show that a correct understanding of 14C data excludes models motivated by the error

An Imbalance in Atmospheric 14C Creates an Opportunity

Finding the True 14C Concentration

Discussion

Findings

Conclusions