In 1957, 92 percent of American children were potty-trained by 18 months of age. Four decades later, that number had dropped to just 4 percent. Why are we potty-training our children so much later than our grandparents did? In large part because of disposable diapers. Made from plastic and cellulose, these products have been refined over several decades to be more absorbent, slimmer and less leaky.

What was marketed as a tool for convenience by the Pampers maker Procter & Gamble in the 1960s eroded the incentives to start potty training early, freeing children from the feeling of wetness that comes from cloth and freeing parents from the inconvenience of washing used diapers or sending them out to be professionally cleaned.

Such convenience comes at a heavy environmental price. Between 2011 and 2018, disposable diapers were among the top 25 most littered items on the seafloor and among the 40 most littered items on land, one study found. In the United States alone, more than 18 billion diapers are discarded every year, creating an enormous drain on natural resources.

Over the course of the past century, disposable plastics undeniably have made our lives easier in many ways. They have also quietly and profoundly reshaped the ways we eat, shop, raise children and understand hygiene and progress.

Plastic has unleashed a tidal wave of waste, most of which flows to landfills and incinerators or ends up as litter harming biodiversity, the climate and human health. We are saddled with an addiction to disposability so deep that tackling it will require a wholesale rewriting of the rules that have governed business and consumption for the past 70 years.

Plastics, first invented some 150 years ago, saw huge growth during World War II as materials such as metals, rubber and silk ran short. After the war wound down, the plastics industry pivoted to targeting housewives and discovered that disposable products were highly profitable.