जलवायु परिवर्तन प्रत्यक्ष रूप से मानव स्वास्थ्य को कैसे प्रभावित करता है?

Prolonged exposure to extreme cold temperatures may result in tissue damage known as frostbite, which is categorized as a:

In the context of ecosystem energy dynamics, which of the following expressions correctly defines Net Primary Productivity (NPP)?