AD - Why are plants colder than their surroundings?

The video explores why thermal cameras show plants being approximately 5°C colder than their surrounding environment, despite receiving the same sunlight and air temperature. The initial hypothesis that concrete absorbs more sunlight than plants proved incorrect, as both absorb similar amounts. Photosynthesis also doesn't explain the temperature difference, as plants only use about 1% of solar energy for sugar production. The actual mechanism involves the stomata—tiny pores plants must open to extract carbon dioxide from the air. When stomata open, the moist interior of the leaf is exposed to hot, dry air, causing water to evaporate. This evaporation process is energy-intensive, requiring approximately 2,400 joules per milliliter of water. This energy comes directly from the leaf, meaning up to 50% of the sunlight a plant absorbs goes into evaporating water rather than heating the plant tissue. In contrast, concrete has no readily available water to evaporate, so virtually all absorbed sunlight converts to heat. This plant cooling effect extends to urban environments—Madrid's El Retiro Park cools surrounding air by up to 2.8°C, with effects reaching up to 600 meters into the dense city center. The video then uses this principle as a transition to discuss heat management in electronics, specifically the Anker Prime Charger, which uses thermal silicone and graphene structures to dissipate excess heat from power conversion.