Greenhouse gases (GHGs) in the atmosphere act like a blanket that keeps the earth warm. This protective blanket helps make our planet habitable. But over the past 200 years, humans have greatly increased the level of GHGs in the atmosphere by burning fossil fuels like oil and coal. This is like throwing on a second blanket, causing temperatures to rise. Other factors such as deforestation have added to the problem. Trees soak up carbon dioxide, one of the greenhouse gases, from the air. Fewer trees, especially in the tropics, means less CO2 is removed from the atmosphere. The laws of physics dictate that the world will grow warmer and warmer as greenhouse gas concentrations rise. There's no uncertainty about this: scientists have understood the correlation for over a hundred years. Venus is a perfect example of a planet swaddled thickly in greenhouse gases and too hot. Are scientists still debating climate change No.