Thread by @WIRED

Extreme weather is crippling lettuce, making it more vulnerable to contaminants like E. coli than ever before. Which raises the question: Can lettuce survive climate change? 1/ wired.trib.al/7Y2kAhx

Recently, it’s become clear that lettuce (specifically romaine) has a problem. There have been several tragic outbreaks in the last few years. 2/ wired.trib.al/7Y2kAhx

The problem? Scientists can’t quite pin down what’s behind the outbreaks. In November, the CDC suggested that people avoid romaine altogether, as they couldn’t find a common source. 3/ wired.trib.al/m1ov6rz

Part of this problem is down to traceability. In the United States, we do a terrible job of tracking the path our produce takes from farm to fork. One proposed solution? Blockchain. 4/ wired.trib.al/m1ov6rz

There is one thing we know for sure though: dirty farm water is making us sick. Growers aren’t required to test their irrigation water for pathogens such as E. coli. As a result, contaminated water can end up on fruits and vegetables, like lettuce. 5/ wired.trib.al/vOgmtBU

E.Coli, which is a gut bacteria, is likely caused by runoff from nearby cattle farms. So farmers have been doing what they can to protect their turf. 6/ wired.trib.al/vOgmtBU

After this recent run of extreme weather—unusual frosts and strong winds— a new hypothesis emerged. The freeze, farmers figured, blistered the leaves, breaking up their surface. Then the winds blasted bacteria into those breaks, where they couldn't be washed away. 7/

Research has predicted that climate change will make food more costly as water runs out and temperatures change. Adding equipment to watch for a heightened risk of foodborne illnesses will push prices up even higher. 8/ wired.trib.al/7Y2kAhx

But disease outbreaks impose costs too: in healthcare spending, in lost productivity, in worry and grief. One way or another, climate change will cost all of us. The growing risk that's now attached to our salads is just one tiny example. Read more: 9/ wired.trib.al/7Y2kAhx