5.1 Describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops

- Light penetrates through the glass into the internal surfaces
- Light is absorbed by surfaces inside the glasshouse (eg. Plants, Wood and soil)
- The surfaces would re emitted as heat, heats warm the air
- The heat warms the air, raising its average kinetic energy causing the temperature to increase
- Warm air becomes trapped inside the glasshouse