Researchers from WP1 of the Tipping Points project, ‘Rapid Neo-glacial transitions in the North Atlantic’, are embarking on a quest to collect artefacts (such as non-biting midges and pollen grains) that will be used to reconstruct past temperature records in order to reveal what the climate was like thousands of years ago. This is the first trip that researchers will make to recover samples for the project.
Above is a map showing the part of Greenland the team will be travelling to. The reason for choosing this part of Greenland to do field research is because it is adjacent to the North Atlantic where a rapid cooling event occurred about 5000 years ago after a warm period known as the Holocene Climatic Optimum (also known as the Holocene Thermal Optimum). It is this period of rapid cooling that is of most interest to Tipping Points researchers.
Fortunately, Greenland is not incredibly cold this time of year, but scientists travelling to the field sites will be walking great distances and living without any modern conveniences beyond their technical equipment. The artefacts they will be collecting are important indicators of past climate. Non-biting midges (chironomids), for example, are incredibly sensitive to water temperature, which is influenced by air temperature, but also other factors such as insolation (amount of incoming solar radiation). The goal is to find the temperature dependencies of midges located in different areas around the North Atlantic. Using chironomids to reconstruct past climate has been used by other researchers such as entomologist Dr Steve Brooks at the Natural History Museum, who is collaborating with Tipping Points.
While there are challenges involved in using chironomids for this purpose, they are still one of the best indicators available for reconstructing past temperature records.
Below is a chart showing the different reconstructions of temperature that have been done in the past for the Holocene. As you can see, not all of them provide the same smooth curve, so an average is taken (black line). This chart is merely an example of how scientists have reconstructed temperature for the Holocene. More information about it is available here.