In 1856, American scientist Eunice Foote placed glass cylinders filled with different gases in the sunlight. The one containing carbon dioxide heated up the most and cooled the slowest. She concluded that an atmosphere richer in CO₂ would mean a warmer Earth. Long forgotten, her finding came three years before John Tyndall's work, often presented as the starting point.
On 27 August 1883, the eruption of the Indonesian volcano Krakatoa was heard as far away as Rodrigues Island, nearly 4,800 km away. Its pressure wave was picked up by barometers worldwide and circled the globe several times. The tsunamis that followed killed more than 36,000 people.
The deepest known point in the ocean, Challenger Deep, lies roughly 10,900 m below the Pacific surface. Drop Everest in and its summit would still sit about 2 km underwater. Down there, the pressure is more than 1,000 times what you feel at sea level, roughly a tonne pressing on every square centimetre.