Severe environmental irregularities, such as droughts or storms that can cause massive crop failure and famine, have repeatedly taken their toll on human populations. Although more subtle climatic variations can also have considerable effects on ecological processes (Stenseth et al. 2002), humans have generally been assumed to be sheltered from these influences. Young children, however, can be very sensitive to seasonal and regional variations in weather conditions and food availability, even outside periods of massive famine (Lummaa and Clutton–Brock 2002). In pre-industrial populations, infant mortality was commonly high; it was not rare that 20–30 % of newborns died annually before reaching the age of 1. The conditions experienced around birth may also have long lasting consequences on adult life-history (Lummaa and Clutton-Brock 2002). For instance, environmental effects experienced at young age, such as the one associated with the month of birth, have been shown to affect adult life expectancy (Doblhammer and Vaupel 2001; Gagnon 2012). Yet, evidence of climate induced cohort effects in humans remain scarce outside disastrous situations, as few longitudinal datasets allow the comparison of yearly environmental variations with survival rates (Galloway 1985; Hayward et al. 2012). Many pre-industrial populations relied mostly on subsistence agriculture and fishing, making them especially vulnerable to environmental variations (Lee et al. 2006; Rickard et al. 2010; Hayward et al. 2012). Proxies of historical environmental variations are increasingly available in reconstructed climatic variables that offer annual measures over very long periods of time (Brazdil et al. 2005). For instance, data on reconstructed solar irradiance (SI) and Northern Atlantic Oscillation (NAO) are now available over centuries (Lean et al. 1995; Luterbacher et al. 1999; Lean 2000) allowing us to investigate the effects of historical climatic variation on preindustrial human population dynamics. There are increasing evidence that SI and NAO correlate with global weather (Stenseth et al. 2002; Pustil'nik and Yom Din 2013) and ecosystem processes such as plant productivity and animal population density (Currie and O'Brien 1993; Coulson et al. 2001; Ottersen et al. 2001; Klvana et al. 2004). Yet, effects of SI and NAO on human health are not so simple to predict as they can be region specific or even have direct effects on human health. Ultraviolet radiations can caused deleterious damage to DNA which is thought to increase fetus loss and reduce lifespan (Melnikov 2012 but see Helle 2009). Nevertheless, the question remains as whether or not subtle large scale cosmic and atmospheric factors can leave a perceptible signature on population growth. To address this question, we used the detailed population Register of a pre-industrial insular Canadian population at the ile aux Coudres (Boisvert and Mayer 1994), over 180 years, and investigated if SI and NAOwere related to infant viability Electronic supplementary material The online version of this article (doi:10.1007/s10745-014-9671-7) contains supplementary material, which is available to authorized users. P. Bergeron (*) : E. Milot Groupe PRIMUS, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke J1H 5N4, Canada e-mail: Patrick.bergeron@usherbrooke.ca