A new study of tree rings in Scandinavia is helping to resolve a longstanding question about the Medieval Warm Period.
A new study of tree rings in Scandinavia is helping to resolve a longstanding question about the Medieval Warm Period.
Past studies of tree rings had indicated that the Medieval period was as warm or warmer than today, but climate models found otherwise. Climate deniers have long pointed to the tree-ring data to suggest the current period of warming is not without precedent.
The new tree-ring study, which used more precise methods than prior research, agrees with the climate models.
For the study, researchers gathered data from 188 Scots pines, both living and dead, in Sweden and Finland. While past studies largely looked only at the width and density of rings, the new study analyzed tree rings at a microscopic level, examining 50 million tree cells to infer changes in temperature — cell walls tend to grow thicker in hotter weather, which is why a darker layer of each ring forms in late summer.
Read more at Yale Environment 360
Photo Credit: 1195798 via Pixabay
