Category Archives: paleoclimate

Frost fairs and the Little Ice Age

The term ‘Little Ice Age’ refers to a period of cooler temperatures between around 1400 and 1850, although a range of dates are used. This climate feature has been inferred from various types of direct and indirect evidence, but it is still not clear how widespread these cooler temperatures were.

A new article by Lockwood et al explores some of the commonly used indirect evidence such as paintings and the occurrence of ‘frost fairs’ on the Thames. We also address the common assumption that the cooler temperatures were solely due to a reduction in solar activity (the Spörer and Maunder minima). Although this assumption is almost certainly wrong, the two features are sometimes considered to be synonymous.

Continue reading Frost fairs and the Little Ice Age

A world before ice

The Earth hasn’t always been struggling with global warming. Around 34 million years ago at the Eocene-Oligocene Transition (EOT) the Earth was undergoing a period of global cooling. This significant shift in climate led to the formation of the first permanent ice sheets of the Cenozoic Era over Antarctica, as shown by the dramatic shift (in a geologic sense) in the oxygen isotope records [1]. The cooling, likely a result of declining atmospheric carbon dioxide levels but potentially also coinciding with Southern Ocean gateway changes, turned Antarctica from a green forested continent to the land of ice we know today. This is illustrated with an image of how this world might have looked.

Guest post by Alan Kennedy, University of Bristol Continue reading A world before ice