पृथ्वी के वायुमंडल में कार्बन डाइऑक्साइड (CO2) का अनुमानित प्रतिशत कितना 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)?