
The biotech company Perfect Day “makes and sells milk, but has no cows”, says Graham Lawton in New Scientist. Its farm is “a bioreactor in which it cultivates micro-organisms genetically engineered to secrete milk proteins”. The proteins don’t resemble milk – they are milk, identical to the real thing. No one else is doing this, but within a year, everyone will be.
This “precision fermentation” involves cloning the gene that produces chymosin – an enzyme found in cows’ stomachs – then sticking it in yeast as you would to make cheese or yoghurt.
This milk can be made without lactose, to which many people are intolerant, can contain healthy fats and could be fortified with nutrients. And there’s no need to pump cows full of antibiotics and hormones, which could make it healthier than the real thing. Ice cream, breast milk and cream cheese are all around the corner – the possibilities are endless. “If an animal can make it, it’s likely that we can make it too.”
The dairy lobby isn’t thrilled: it has persuaded the EU to ban plant-based nut and oat alternatives from describing their products as “milk”. But producing milk in a live animal is “fantastically inefficient”. The dairy industry is responsible for 4% of our greenhouse-gas emissions, more than shipping and aviation combined. Take cows out of the equation and “the problem vanishes”.
Computer says yes to saving the planet

We’re losing hope that humans can fix climate change, says Dan Charles on NPR. So the Intergovernmental Panel on Climate Change looked at giant computer simulations of the world’s economy to see whether it’s even possible.
There are six of these “integrated assessment models”: four in Europe, one in Japan and one in the US. They’re fed data on cars, buses, auto rickshaws, planes, power plants, home furnaces and rice paddies. The models also include assumptions about international trade, prices and the costs of new technologies. So, can we really cut greenhouse-gas emissions to zero within 40 years?
The good news is that the computers say yes. In these virtual worlds, people respond to higher fuel prices or government regulations by moving to more energy-efficient houses, and give up their cars in favour of a new, better kind of public transport where “autonomous vehicles respond like Uber”. Between 10 and 20 times more land is covered with solar and wind farms. Political or human intransigence is a red flag. But the numbers stack up. “They’re all dramatically different from the situation today.” The machines, at least, say there’s a way out.