Our daily adventure around the world

💋 The earliest recorded kiss dates back ~4,500 years to Mesopotamia. Previous research had suggested that romantic kissing first began ~3,500 years ago in modern-day India, but a new review paper published yesterday in Science describes clay tablets from ancient Mesopotamia that show the act of kissing. These predate similar Indian texts by ~1,000 years, though the husband-and-wife team behind the research stressed kissing “did not emerge abruptly or in a specific society,” and was likely practiced in multiple ancient cultures around that time.

🇨🇦 Canada’s central bank said high levels of household debt pose a major risk to the country’s financial system. In an annual report published yesterday, the bank said Canadian households who took on a mortgage over the past three years are carrying 17% more credit-card debt, on average, than those who took out a mortgage during the preceding three years. The bank also expressed concern over what will happen in the near future as existing mortgages start to feel the impact of recent interest-rate hikes (since under Canadian law, mortgages are renewed with new interest rates after a certain period).

🌏 Each El Niño costs the global economy an average of $3.4 trillion, per a new study. The peer-reviewed findings, published yesterday in Science, attempted to capture El Niño’s overall cost by calculating the total amount of money that’s diverted away from technology and innovation, and towards recovery and rebuilding efforts. The study did so by simulating what world GDP would’ve been without a certain El Niño event, then comparing that to actual GDP – though many outside economists pushed back on the Dartmouth researchers’ conclusions.