Which term describes resources that must be used immediately or they could be lost?

The term that describes resources that must be used immediately or they could be lost is flow resources. Flow resources are characterized by their nature of being available only for a limited time or in specific seasons. For instance, natural phenomena such as sunlight, wind, and running water are classified as flow resources because they are consistently available but can only be harnessed when they are present. If not utilized promptly, these resources can diminish or change, making timely usage essential to their effectiveness.

Renewable resources, while also involving natural assets, can be replenished over time and are not strictly time-sensitive in the same manner as flow resources. Non-renewable resources refer to materials that exist in finite amounts and take millions of years to form, like fossil fuels, which are not characterized by immediate usability. Input resources generally refer to factors essential for production but do not convey the idea of urgency associated with flow resources. Hence, flow resources accurately capture the concept of timely use or risk of loss.