Today, in our environmental science lecture, we'll discuss the impact of urban green spaces on air quality. A recent study in London found that planting trees along busy roads can reduce particulate matter by up to 30%, but only if the trees are spaced correctly. However, the effect is limited when buildings are too tall, as they trap pollutants. Interestingly, green roofs are less effective for street-level pollution but help with building insulation. Therefore, city planners should prioritize street trees in open areas, not just parks.
❓ According to the lecture, what is the main benefit of planting trees along busy roads?
A. A. They improve building insulation.
B. B. They reduce particulate matter by up to 30%.
C. C. They are more effective than green roofs in all cases.