What would happen if all refrigeration stopped?

Chilling is the single most effective way to slow the bacterial growth that spoils food and causes foodborne illness, and around a third of all food produced is already lost or wasted with refrigeration working. Without it, fresh meat, dairy and fish become unsafe within hours in warm conditions, and food systems would revert to salting, drying, canning, fermentation and daily local shopping. The larger consequence is medical: many vaccines require storage between 2 and 8 °C, some far colder, and the cold chain is what makes global immunisation programmes possible at all. Blood products, insulin and a long list of other medicines have the same requirement. Refrigeration also underpins air conditioning, which is what makes several densely populated regions habitable in summer and which measurably reduces heat-related deaths. It is a strong candidate for the most consequential invention people never think about.

How confident this is

This is a reasoned extrapolation rather than an observation. The mechanism is understood, but the scale of the consequences depends on assumptions that could reasonably be argued differently.

Everyday systems

• What would happen if everyone on Earth jumped at the same time? Essentially nothing. All of humanity together is about one ten-trillionth of Earth's mass.
• What would happen if the internet went down? Payments fail first, then logistics — most physical supply chains now depend on network connectivity rather than the other way round.
• What would happen if all the power went out worldwide? Water supply is the first life-critical failure — most tap water is pumped, and pumping stops when the grid does.
• How much space would it take for everyone on Earth to stand in one place? About 2,000 square kilometres — smaller than Luxembourg, and less than twice the area of Los Angeles.
• What would happen if GPS stopped working? Timing, not navigation, is the real dependency — mobile networks, power grids and financial systems all use GPS clocks.
• What would happen if money stopped existing? Trade would collapse to what barter can support, and something money-like would be reinvented within weeks.
• What would happen if all the satellites stopped working? Weather forecasting would lose most of its accuracy beyond a day or two, along with navigation, timing and most long-range communications.
• What would happen if the water supply stopped? Three days for drinking, but sanitation fails first — waterborne disease is what historically kills people in a water outage.
• What would happen if all digital data was lost? Ownership would be the deepest problem — land registries, bank balances and medical records exist almost entirely as data.