Explain how the increasing use of fossil fuels and changes in agriculture may have contributed to global changes in temperature.

Here, think about splitting the answer into two, fossil fuel impacts on global temperature and then agricultural impacts. Initially you could comment an introductory sentence on the current trends of global trend. Finally you could contemplate the joint impact the two would have together on the global change and what the likelihood of this would be. I would recommend sources for this information to come from IPCC report executive summaries, as well as any lesson notes etc.