The Greenhouse Effect

Introduction

Greenhouses allow gardeners to grow plants in cold weather. This is because the air inside the greenhouse stays warmer than the outside air. Short wavelength radiation from the sun passes through the glass, warming the interior of the greenhouse. The longer-wavelength radiation emitted does not pass through glass and is trapped in the greenhouse. This, along with the lack of mixing between the inside and outside air, keeps the greenhouse consistently warm.

On a larger scale, the greenhouse effect helps keep our planet warm. Short wavelength radiation from the sun passes through the atmosphere, warming the Earth. The longer wavelength energy is then trapped by certain gases called greenhouse gases. The greenhouse gases most responsible are water vapor, carbon dioxide, methane, and nitrous oxide.

In this experiment, you will use two Temperature Probes to measure and compare the temperatures in model greenhouses under various conditions. In Part I, you will investigate the role of a plastic covering over the top of the model greenhouse. In Part II, you will investigate the effect of increased levels of two greenhouse gases – water vapor, H₂O, and carbon dioxide, CO₂.

Objectives

In this experiment, you will

• Use Temperature Probes to measure temperatures in a model greenhouse and a control.
• Use the results to make conclusions about the greenhouse effect.