Greenhouse debt is what happens when countries produce too much pollution by burning fossil fuels like coal and oil. When these fuels are burned, they release gases that trap heat inside the atmosphere and make the planet hotter. This is like a greenhouse, so it's called 'greenhouse' debt. In some cases, the extra heat can be harmful to the planet and can cause extreme weather events like floods and droughts. To reduce greenhouse debt, countries can try to produce less pollution by using cleaner energy sources like solar and wind power. They can also plant more trees, which absorb carbon dioxide and help cool the planet.