Final answer:
The combustion of coal, oil, and natural gas directly contribute to global warming.
Step-by-step explanation:
The human activity that directly contributes to global warming is the combustion of coal, oil, and natural gas. When fossil fuels are burned for energy, carbon dioxide and other greenhouse gases are released into the atmosphere. These greenhouse gases trap heat from the sun and cause the Earth's temperature to rise, leading to global warming.
For example, when coal is burned in power plants to generate electricity, huge amounts of carbon dioxide are emitted. Similarly, when gasoline is combusted in cars for transportation, it also releases significant amounts of greenhouse gases.
Overall, the combustion of fossil fuels is a major contributing factor to global warming and climate change.
Learn more about global warming