1. Explain the difference between C3 and C4 plants and describe how changing climate could impact the geographical spread of these plants?

C3 plants are plants that obtain CO2 from the air during the initial steps of photosynthesis and create C3 in the Calvin cycle, while C4 plants are plants grow during the warm locations that obtain CO2 from the air during the initial steps of photosynthesis and form C4 in the mesophyll cell. C3 plants are the most common and found in cool climates, while C4 plants are found in warm climates. Changing climate could increase in geographical distribution of C4 plants if the climate warms because the it promotes ideal conditions for C4 plants, while C3 plants would slowly decrease. If the climate were to cool, C4 plants would decrease and C3 plants would be dominations because it creates an ideal environment for C3 plants. 

2. With the potential change in temperature during the spring and autumn months, what long term socio-economic problems do you think countries in the mid-to-upper latitudes might face?

The socio-economic problem that I think countries in the mid-to-upper latitudes might face are a farming, tourism, water supply, and health issues.  Farming might decrease because temperature changes can create drought conditions that will stunt the growth of crops. Crops are a large economic contributors in the the mid-latitudes and can create major socio-economic problems if disrupted. Tourism might also go into decline because the changes in temperature might make people less interested in traveling to mid-latitude locations during this time period. Water supplies may also become vulnerable because the demand of water would increase with temperature change. Water is a super valuable resource that will be used to farm, clean, and drink. Lastly, the changes in temperature would increase heat related illness, which would lead to medical expenses. Medical expenses are very costly.