In southwest Florida’s Lee County, hundreds of seawalls built to keep the ocean at bay have crumbled. During Hurricane Irma, high winds rapidly sucked the seawater away from the structures, leaving them exposed on the ocean side. Simultaneously, heavy rains caused flooding on land, which drained toward the walls. Without the ocean to support them, they buckled under pressure from the rushing floodwater. Soon after, an intense storm surge sent seawater roaring back toward the land—right over the crumbled walls. Properties that had been protected suddenly were not.

Hundreds of seawalls in Florida were breached, posing challenges for local governments. “The city does not have the necessary manpower or materials to address all of these failures,” the city of Punta Gorda said in a press release. The city is seeking contractors to repair the walls, but not many such companies exist and those that do are stretched thin after Irma. One company reported getting 200 to 400 calls per day. “We were busy before this with new construction,” Melanie Williamson, of Williamson & Sons Marine Construction in Cape Coral, Florida, told the local News-Press. “We came in this morning and had another 50 message on the phone and it just doesn’t stop. So it’s a pretty serious situation.”

Seawalls are perhaps the most well-known line of defense from sea-level rise. And yet they were not enough to protect some coastal communities in Florida this month. The Trump administration, though it does not accept that human-caused climate change is real, has said it does want to defend against its impacts: rising oceans, more intense rainfall, and bigger storm surges. “We continue to take seriously the climate change—not the cause of it, but the things that we observe,” White House national security adviser Tom Bossert said earlier this month. In other words, we’ll prepare for the result (destruction), but not address the cause (carbon emissions).

But as climate change worsens, and thus brings even more rain and higher seas, will mere adaptation plans be enough to protect lives and property? Let’s consider how existing adaptation measures fared against hurricanes Irma, Harvey, and Maria.

Lee County was not the only place where man-made defenses against major hurricanes went awry. In Brevard County, water pumps were installed to reduce flooding and flooding during storms. They’re working, but not well enough; floodwaters were still standing in some places more than a week after the storm. In Miami Beach, an $11.5 million beach widening project was undertaken to protect the island from hurricane storm surge. It was completed six months ago, but Irma blew away massive chunks of sand and narrowed it back down. Storm surge still wound up inundating the streets. Miami Beach also recently raised 105 miles of roads in an attempt to prevent flooding, but according to the Miami Herald, the area “saw its streets near the Venetian Causeway turn into, well, Little Venice.”