<s>[INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question. If you don't know the answer, just say that you don't know. Use three sentences maximum and keep the answer concise. Question:  Which gas is mainly responsible for global warming? Context: Carbon dioxide (CO2) is the main gas responsible for global warming. Answer: [/INST]Carbon dioxide (CO2).</s>