Paul A. Murtaugh and Michael G. Schlax make their case in "Reproduction and the Carbon Legacies of Individuals," published in the journal, Global Environmental Change. "While population growth is obviously a key component of projections of carbon emissions at a global level, there has been relatively little emphasis on the environmental consequences of the reproductive choices of an individual person," they argue. After all, there are not only the "immediate effects" caused by each offspring, but also the "additional impacts" if these offspring eventually produce further offspring.
According to the study, a single female's decision to reproduce even a single child could have tremendous ecological effects. In order to make their case, the researchers traced a hypothetical single female's "genetic contribution to future generations" and projected the carbon legacy this contribution would entail. They posit that each child will add 9441 metric tons of carbon dioxide to the carbon legacy of an average female.
To their credit, the researchers have invested considerable thought into exactly how they might project this "carbon legacy." They made their calculations with the understanding that children, both male and female, are likely to enter into reproductive pairs and produce future generations. They assumed a reproductive rate of 1.85 children per woman by the year 2050.
Taking all this into account, Murtaugh and Schlax estimate that a woman in the United States who makes significant lifestyle adjustments in order to reduce her own carbon legacy -- such as increasing her car's fuel economy, reducing miles driven, adopting energy-efficient technologies, recycling, etc. -- would save about 486 tons of carbon dioxide emissions over a lifetime. Yet, "if you were to have two children, this would eventually add nearly 40 times that amount" of carbon dioxide to the atmosphere. In other words, all her efforts to be environmentally conscious and careful would be overwhelmed by her decision to have just two children.
The researchers argue:
Clearly, an individual's reproductive choices can have a dramatic effect on the total carbon emissions ultimately attributable to his or her genetic lineage. Understanding the ways that an individual's daily activities influence emissions and explain the huge disparities in per capita emissions among countries is obviously essential, but ignoring the consequences of reproduction can lead to a serious underestimation of an individual's long-term impact on the global environment.
In one sense, a scientific report like this could represent little more than a hypothetical answer to a conjectured question. Nevertheless, more is at stake here. These researchers make this point clear when, early in their article, they assert: "Our basic premise is that a person is responsible for the carbon emissions of his descendents, weighted by their relatedness to him."
This is a quite remarkable assertion. While these two researchers have addressed their report to the scientific community, they openly acknowledge that their argument should be taken into consideration by those concerned with the policy challenge of climate change. As they argue, "Clearly, the potential savings from reduced reproduction are huge compared to the savings that can be achieved by changes in lifestyle."
Warnings that human reproduction will lead to ecological disaster have been common since at least the 1960s. Generally, these arguments have been couched in considerations of limited natural resources and environmental sustainability. Now, a new element is added to the mix, complete with a proposed model for quantifying a projected environmental impact. These two researchers advise that failing to take "reproductive choices" of individuals into account will effectively doom all other efforts to reduce the level of carbon emissions.
The logic of this argument is clear and chilling. The leap from scientific analysis to proposals for public policy is almost sure to come. How long will it be before prospective parents are warned that their decision to reproduce could be catastrophic for the environment? Should we now expect a cap and trade proposal for babies?
Anti-natalist philosophies have been around even longer than arguments over ecology and sustainability. Given our biblical responsibility for environmental stewardship, Christians should indeed be thoughtfully engaged with the entire nexus of questions related to carbon emissions, climate change, and respect for the Earth. Nevertheless, when we begin to measure babies in terms of a "carbon legacy" and a projected threat to the environment, we abandon the biblical worldview. Human beings cannot be reduced to a "carbon legacy" and the gift of children must never be seen as an assault upon the earth.
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