The link between climate change, food security and fertility: The case of Bangladesh

and duration [5]. In addition to climate change, the world experienced more than 11,000 extreme weather events between 1997 and 2016, resulting in more than 524,000 deaths and $3.16 trillion in economic losses. According to the 2020 Global Climate Risk Index (CRI), the top ten countries most affected by the number of extreme events between 1999 and 2018 are: Philippines (n = 317), Vietnam (n = 226), Bangladesh (n = 191), Nepal (n = 180), Pakistan (n = 152), Thailand (n = 147), Haiti (n = 78), Myanmar (n = 55), Puerto Rico (n = 25), and Dominica (n = 8) [6]. About 108 million people living in 48 countries at risk of food crises were highly vulnerable or already experiencing acute food insecurity in 2016 [7]. Climate change reduces agricultural production and increases food insecurity due to abnormal precipitation and temperature changes [8–10]. The impact of climate on agriculture is region-specific mainly [11]. Bangla- desh is one of the most vulnerable countries to climate change and variability [12, 13]. Accord- ing to the Global Climate Risk Index 2020, Bangladesh experienced 191 climate-related extreme events between 1999 and 2018 [6]. Extreme climate events such as floods, cyclones, and droughts are common in Bangladesh [14–16], which have serious impacts on the liveli- hoods of vulnerable populations [17–19]. Climate change, such as the steady rise in tempera- ture and changes in precipitation patterns, has severely affected several sectors in Bangladesh, including agriculture, water resources, and public health [18, 20]. The cultivation of crops,

especially rice, is often limited by various climate hazards–floods, droughts, soil and water salinity, cyclones, water waves, etc.–in the country. Population dynamics such as mortality, migration, and fertility can undergo significant changes due to climate variability or natural disasters [21–23]. Human geographers and demographers have previously studied the effects of climate variability on health [24, 25], migration [26–28], and mortality [29]. Climatic extremes have already adverse effects on Ban- gladesh’s population sectors, including child mortality [30], migration [31], and child marriage [32–34]. In this study, we are interested in the effect of climate change on fertility, which has received less attention [35]. There are studies on the relationship between environment and ideal family size and family planning practices [36–43]. Thus, poor environmental conditions or increasing environmental degradation are expected to affect child demand and fertility. The effect of firewood and water scarcity on fertility was found to be positive in South Africa [36] and Nepal [39], while another study in Nepal found a negative relationship [44]. Similarly, a positive relationship between water scarcity and fertility was found in Honduras and Nepal [38]. In response to fuel and water shortages and increased harvest seasons, married indige- nous men and women living in reserved forests in Bangladesh were more likely to have more children who could work and earn money through other livelihood opportunities [41]. In

terms of the effect on family planning behaviour, Ghimire and Mohai found that, in Nepal, those who believed that current agricultural productivity had decreased from three years ear- lier were more likely to use contraceptives than those who believed that current agricultural productivity had remained about the same or increased [40]. Since Bangladesh is a predominantly agricultural country, climate change could exacerbate food insecurity by affecting crop production and, indirectly, fertility. This study aims to find out if and how climate change affects fertility in the country. Specifically, the direct and indi- rect effects of climate change (e.g., temperature and precipitation) on major crops and the short- and long-term effects on fertility are examined. The results of this study can add exciting insights and arguments to the existing literature on population dynamics and climate change impacts. They can also deepen our understanding of the linkages between climate change, food security, and fertility. The next section presents the conceptual framework of this study in relation to climate change, food security, and fertility to justify and explain the purpose of the study. This is PLOS ONE Climate change, food security and fertility PLOS ONE | https://doi.org/10.1371/journal.pone.0258196 October 21, 2021 2 / 18 Divisions (https://population.un.org/wpp/). We also collected data on fertilizer use (i.e., the amount of crop nutrients used per unit of arable land) from the World Bank (https://data.worldbank.org/). Data on GDP per capita and the percentage of value

added from agriculture, forestry, and fisheries in GDP were from the World Bank (https://data. worldbank.org/). Funding: The author(s) received no specific funding for this work. Competing interests: The authors have declared that no competing interests exist.