Final answer:
True, renewable energy sources for vehicles, such as biofuels, can help address transportation emissions, but they are limited by competition with food production, land use, and low efficiency in harvesting solar energy.
Step-by-step explanation:
The statement 'Promoting vehicles powered by renewable energy sources to harvest the crops and getting them to market would address the transportation concerns of the farming community and the global problem of increasing CO2 emissions' can be considered true to an extent. Renewable energy sources for vehicles, such as biofuels from crops, present a partial solution to reducing carbon emissions in transportation. However, there are constraints to consider. While biofuels like sugar cane and vegetable oils fare better than corn ethanol, they compete with food production and require significant arable land. Additionally, the destruction of natural carbon sinks to expand agricultural land offsets some of the emissions benefits. Moreover, plants have a low efficiency rate of 1-2% for harvesting solar energy. Therefore, scaling biofuel production to a meaningful level is challenging. The use of biofuels also requires substantial land use, potentially leading to biodiversity loss and ecological strain.