The article explores how a global carbon tax on fossil fuels can help reduce greenhouse gas emissions and limit climate change impacts. By analyzing different scenarios, the researchers found that the tax can be effective in certain conditions, leading to changes in energy sources and land use. In scenarios with low population growth and sustainable practices, the tax can help maintain the balance of carbon in the environment. However, in scenarios with high population growth and low sustainability, increased demand for cropland may turn the land from a carbon sink to a carbon source by the end of the century.