It takes more than 150 people to make a cup of coffee, from farmer to barista. But if that final person makes a mistake, your precious coffee is wasted. Michael Allen investigates whether physics can help us brew smarter so we don’t waste a product that’s threatened by climate change (Courtesy: iStock/Hispanolistic) Espresso, flat white, cappuccino, cortado – there are dozens of ways you can get your coffee fix. Every day more than two billion cups of coffee are brewed worldwide, making it one of the most traded products on Earth. In fact, it is the seventh most traded commodity on the planet (after crude oils, natural gas, gold, silver and copper). Produced mainly in south and central America, south-east Asia and east Africa, coffee sustains the livelihoods of more than 25 million farming households . But its future is increasingly precarious. Coffee plants need the right temperature range, rainfall patterns and altitude to thrive, but climate change is disrupting it all.…