Climate adaptation requires extensive human management, but what happens when the best laid plans go wrong? This was the case on the Louisiana coast: as land disappeared from beneath Isle de Jean Charles, physical realities forced people to relocate.

In 1976, Isle de Jean Charles was five miles wide, surrounded by marsh, cypress groves and pasture, where families raised cattle, fished and grew their own food. Over decades, that land was steadily lost to rising sea levels, land subsidence and storm surges. Today, 98% percent has disappeared, making it uninhabitable.

The response, as outlined in this fascinating piece in the New York Times, was the construction of New Isle, built inland with $48 million in federal climate‑resilience funding from the U.S. Department of Housing and Urban Development. This marked the first use of federal tax dollars to move an entire community affected by climate change in a process known as “managed retreat”.

It was a landmark moment, with significant investment, an elongated timeline, and a process that was (ostensible at least) designed with extensive outreach efforts – and yet it still resulted in mixed outcomes. Many residents remain angry about how the money was spent, and the misalignment in their new community with previous ways of life. Funds went to a community centre they rarely use and to water they do not want to fish in. A second phase intended to house more island families failed when no-one could afford to build. Instead, a charity constructed homes that have sat empty for months.

New Isle shows that even when climate retreat is managed through a decade of planning and a multi-million dollar budget, it can’t necessarily contend with the messiness of human communities and their multiple webs and ties. It’s an undeniably ominous sign for a world in which climate migration is going to be a reality for multitudes in the coming years. Rather than just being a cautionary tale, we hope that it can offer learnings to future efforts, and that other projects can get right what it got wrong.