<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:  What is the main cause of global warming? Context: Greenhouse gases, particularly carbon dioxide emissions from human activities, are the main cause of global warming. Answer: [/INST]The main cause of global warming is the increase in greenhouse gases in the atmosphere, primarily carbon dioxide emitted from human activities.</s>