Understanding plant greenhouses vs. atmospheric greenhouse effect Which statement about a plant “greenhouse” is incorrect (i.e., the wrong statement)?

Introduction / Context:
Confusion often arises between a horticultural greenhouse and the planetary greenhouse effect. Exam questions probe whether you understand transmission properties of glass and the qualitative analogy to atmospheric CO2. Here, you must identify the incorrect statement among several about how a greenhouse works and how it compares to Earth’s atmosphere.

Given Data / Assumptions:

• Greenhouse glazing is glass (or similar) with characteristic spectral transmission.
• Greenhouse interior warms due to radiation and reduced convective exchange.
• Earth’s greenhouse effect is due to gases absorbing longwave infrared.

Concept / Approach:
Glass transmits most visible light but substantially blocks ultraviolet (especially UV-B and UV-C). Therefore, a statement that says glass allows visible sunlight “including ultraviolet” to pass is inaccurate. The warming inside a greenhouse results from shortwave transmission, longwave trapping, and reduced convection. For the atmosphere, increasing CO2 reduces outgoing longwave radiation, raising surface temperature—an analogous but not identical mechanism to a glasshouse.

Step-by-Step Solution:

Verification / Alternative check:
Spectral transmission curves of standard soda-lime glass show high transmittance in visible, low in UV-B/UV-C; many horticultural films still attenuate UV significantly.

Why Other Options Are Wrong/Right:

• (b): Correct qualitative description of longwave interaction with glass.
• (c): Correct qualitative analogy for atmospheric CO2 absorbing infrared.
• (d): Obviously false; real greenhouses are warmer inside than outside (this reinforces that (a) is the targeted incorrect spectral claim).
• (e): True; visible transmission is high and drives photosynthesis.

Common Pitfalls:
Assuming “sunlight” automatically includes UV transmission through all glazing; in most greenhouses, UV is substantially filtered unless special materials are used.

Final Answer:
A glass greenhouse allows visible sunlight (including ultraviolet) to pass and heat the soil, warming plants inside.