Bring me sunshine in your spores | Susannah Lydon

Ultraviolet radiation can have huge effects on our planet's climate, but what has it done the past? The fossil record can tell us about UV through the study of pollen and spores

In the middle of winter (in the northern hemisphere at least), it is comforting to think about sunshine. Sunshine is what allows life on this planet. The sun spews out electromagnetic radiation around 93m miles (149m km) away here on Earth, life responds, on all sorts of timescales.

The most obvious type of solar radiation to reach us, and to all the other species which have evolved eyes over the last half a billion years, is visible light. Infrared radiation, with a lower frequency than the red end of the visible light spectrum, and which more or less corresponds to thermal radiation, is also a large component of the sun's radiation. Finally, there is ultraviolet (UV) radiation, with a higher frequency than the violet end of the visible spectrum. This form of radiation enables our mammalian bodies to make vitamin D (good), but can also cause sunburn, and damage to DNA (bad).