The Environmental Kuznets Curve (EKC) hypothesis suggests that as countries become wealthier, pollution levels first rise, then decrease. This is because at early stages of development, environmental quality worsens faster than income grows, but later on, it improves relative to economic growth. The EKC theory is supported by some studies, especially for air quality, but there is no consensus on when exactly pollution starts to decline with rising income. Possible reasons for this trend include the shift from agriculture to industry to services, and the fact that wealthier people tend to value environmental quality more. Overall, the EKC concept remains a topic of debate in the scientific community.