Question

as greenhouse gas concentrations increase across the globe in our atmosphere, we are observing significant changes to our climate. how does climate change directly affect desert regions and humans ability to sustain in these regions?
greenhouse gas increases will cause an increase in desert areas on earth. current desert areas will grow as temperatures cause increased evaporation. humans will migrate away from these areas of low water and productivity.
greenhouse gas increases will cause an increase in weathering of rock, providing an enriched soil content for these areas. more animals will migrate to these warmer, more fertile areas, providing resources which humans can consume.
greenhouse gas increases will cause a greater amount of rainfall to occur in areas once designated as deserts. these areas will be converted into more cultivated land for growing crops.
greenhouse gas increases will cause a greater amount of plant growth to occur in the areas formerly designated as deserts. these areas will soon yield large timber and lumber harvests.

Explanation:

• Greenhouse gas increases lead to higher temperatures. Higher temperatures cause more evaporation. This makes current desert areas expand as water availability decreases. With low water and productivity, humans will migrate away.
• Option 2: Weathering of rock due to greenhouse gas increase is not a main direct effect on deserts in the context of climate change impact on desert regions and human sustenance. Also, deserts are not becoming more fertile in a way that would lead to large - scale animal migration for human consumption resources as described.
• Option 3: Greenhouse gas increase does not directly cause a greater amount of rainfall in deserts. In fact, in many cases, climate change can lead to more erratic and less predictable rainfall patterns, and deserts are likely to become drier rather than wetter.
• Option 4: Greenhouse gas increase does not lead to a greater amount of plant growth in deserts in a way that would yield large timber and lumber harvests. Deserts have harsh conditions (low water, high temperatures) that limit plant growth, and any changes due to climate change are more likely to be negative for plant growth in the context of human sustenance (e.g., not enough water for large - scale plantations).

Answer:

Greenhouse gas increases will cause an increase in desert areas on Earth. Current desert areas will grow as temperatures cause increased evaporation. Humans will migrate away from these areas of low water and productivity.