Carbon dioxide (CO2) (click here) - Fossil fuel use is the primary source of CO2. The way in which people use land is also an important source of CO2, especially when it involves deforestation. CO2 can also be emitted from direct human-induced impacts on forestry and other land use, such as through deforestation, land clearing for agriculture, and degradation of soils. Likewise, land can also remove CO2from the atmosphere through reforestation, improvement of soils, and other activities.
Methane (CH4) - Agricultural activities, waste management, energy use, and biomass burning all contribute to CH4emissions.
Together fossil fuels, industrial processes (including peat burning, wood burning and slash and burn) and methane comprise 81 percent of all the dangerous gases causing the climate crisis.
By far burning gasoline is the largest contributor to the dangers of the climate crisis.