What are the main causes of global warming?

Global warming can be caused by a number of different types of things. Increased solar activity, orbital variations of the Earth, changes in albedo or reflectivity, increases in greenhouse gases, changes in clouds, and so on. the current warming is caused by an increase in greenhouse gases mainly due to human usage of fossil fuels but also due to deforestation, decrease in carbon sinks and release of CO2, and animal farming, increase in methane due to feed type.