Rice paddies can contribute to global warming, but adding straw or biochar can help reduce greenhouse gas emissions. A study found that adding straw with urea increased methane emissions but decreased carbon dioxide uptake and nitrous oxide emissions. Adding biochar with urea also increased methane emissions but boosted carbon dioxide uptake and reduced nitrous oxide emissions. Over 100 years, nitrous oxide emissions had the biggest impact on global warming potential. Using straw decreased global warming potential more than using urea alone, while biochar decreased it even more due to increased carbon dioxide uptake. To improve climate change mitigation, reducing nitrous oxide emissions during fertilization and controlling carbon dioxide emissions after topdressing are suggested.