THEY were tiny and lived – briefly – thousands of years ago.
THEY were tiny and lived – briefly – thousands of years ago. But midges which flitted over lakes in Greenland in the deep past are providing North East experts with insights into how our climate may change in the future.
Antony Long, professor of geography at Durham University, and Dr Eleanor Maddison are studying the remains of midges trapped in sediment samples from lake beds on the edge of the Greenland ice sheet from between 6,000 and 3,000 years ago.
The colleagues are part of the Tipping Point team at the university’s Institute of Hazard, Risk and Resilience.
The five-year Tipping Point project is examining, among other areas, how aspects of the natural world can change abruptly from one state to another – including climate.
“We are looking to see if any lessons or patterns emerge, as early warning tipping signs,” says Prof Long.
The team has made several trips to Greenland and northern Norway to focus on the 6,000-3,000-year time window in the past when the world’s climate seems to have “tipped” from warmer to cooler.
The aim is to establish what caused that tipping and how the data can be used to predict future climate change.
This includes factors such as the rate of ice sheet and glacier melting, and links with ocean and air temperatures, the Gulf Stream and Jet Stream, and how this influences our climate.
Prof Long says: “Some species of midge like cold conditions and others prefer warm and through this we can track how climate has changed.”
As well as the midges, other natural “climate thermometers“ are being examined, like snowflakes, tree rings and pollen grains, which show what was growing on the land at that time around the lakes, and so what the climate was like.
“The remains of the midges which flew out of the lake surface in Greenland thousands of years ago, snowflakes which fell on the ice sheet and the pollen from the tundra on the edge of the lake – these are natural records of climate change,” says Prof Long.
“We are looking at the mystery of the rapid cooling which took place in the climate and our task is to gather evidence of past climate in the form of midges and pollen.
“This will help us to discover how the climate system may change in the future.
“It is a case of how we can unravel these climate signals. We have to make sure we get right because the stakes are very high.”
Prof Long said that there was no evidence of external forces such as volcanic activity or solar energy changes behind the cooling.
Dr Maddison, who is working on the sediment samples, says: “They are an archive of what happened in the lakes in the past.
“We are looking at the biological elements in the core sediment samples to determine how the environment has changed.
“The midges are an important tool for us in looking at the climate. They are everywhere in large numbers, with each species having a specific set of environmental conditions in order to thrive, including temperature.
“This work is really exciting because it gives us a real insight into the climate system. By looking at these smaller animals and plants we can use them to reconstruct past climates.
“We can tease apart records from the sediment that tells us about the climate.
“It gives us the ability to go back and essentially read the sediment like a book from cover to cover.
“It is exciting to see what happened in the past and very important that we understand how these systems worked because if we don’t we will not be able to get to grips with the potential changes in the future.”