Question

as humans reduce the tree coverage in the areas of the united states, forests are becoming converted into urban areas and even farmland. at the same time, increases in greenhouse gases are being measured in teh atmosphere. which of these statements accurately describes the impacts that climate change and human activity will hae on the farmland areas?

increased green house gases will cause a decrease in average global temperatures. this will reduce the crop yield and require a larger area to be used as farmland in the future

reduced tree coverage due to deforestation will mean decreased rates of photosynthesis. the greenhouse gas concentrations in the atmosphere will increase, causing a positive feedback loop with regard to climate change

increased greenhouse gases will cause an increase in the average temperature of the farmlands wich will increase the productivity of the farms. the crops will grow with an increased yield

reduced tree coveragedue to deforestation will be couterbalanced by increased plant growth with climate change. this will be negative feedback that will restore biodiversity

Explanation:

• Option 1: Increased greenhouse gases cause an increase in global temperatures, not a decrease. So this option is incorrect.
• Option 2: Deforestation (reduced tree coverage) leads to less photosynthesis. Photosynthesis consumes \(CO_2\) (a greenhouse gas). With less photosynthesis, greenhouse gas concentrations increase. This increase in greenhouse gases further warms the planet (positive feedback loop). This option is correct.
• Option 3: While some crops may benefit from a small increase in temperature in the short - term, overall, climate change (including extreme weather events, water stress due to altered precipitation patterns etc.) is more likely to decrease crop yields in the long - term. So this option is incorrect.
• Option 4: Deforestation leads to habitat loss for many species. Climate change also causes habitat shifts and species endangerment. There is no evidence that increased plant growth (due to climate change, which is also not a guaranteed positive effect) will counterbalance deforestation to restore biodiversity. So this option is incorrect.

Answer:

B. Reduced tree coverage due to deforestation will mean decreased rates of photosynthesis. The greenhouse gas concentrations in the atmosphere will increase, causing a positive feedback loop with regard to climate change.