<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: The main cause of global warming is the increase of greenhouse gases, mostly due to human activities like burning fossil fuels and deforestation. Answer: [/INST]The main cause of global warming is the increase of greenhouse gases in the atmosphere, primarily from human activities such as burning fossil fuels and deforestation.</s>