When we mention insects, we tend to think of flies, mosquitos, and those pesky cockroaches ruining a perfect summer night.

However, insects and all other arthropods, such as spiders and centipedes, play a very important role in the environment. Arthropods may be responsible for pollinating flowers, controlling plants and other insect populations, as well as aiding in the decomposition of dead animals and decaying plant material. Because of this, arthropods can indicate the state of health of an ecosystem.

Climatologist James Ciarlo` is currently working on project PALEOSIM (PALEOclimate modelling of Small Islands in the Mediterranean and possible impacts on arthropod habitats).

This research focuses on the climate impacts on arthropod habitats of small islands using a Regional Climate Model. A climate model is a computer program that represents known atmospheric physics and chemistry in a virtual environment, using power supercomputers to run simulations of our world’s climate. The Regional Climate Model provides the possibility to study small islands such as the Circum-Sicilian islands, which include Malta and Gozo, and predict variation in arthropod habitats induced by climate change.

Climate change is not just a recent phenomenon. During the last ice age, about 21,000 years ago, glaciers extended as far south as modern-day London. This caused sea levels in the Mediterranean to drop by more than 110 metres when compared to today’s level. Consequently, Europe had a cooler climate, and Malta was a peninsula connected to Sicily. Animals, including insects, were able to spread down to Malta. As the ice age ended, the glaciers receded, sea level rose, and Malta became isolated, drier and warmer.

The PALEOSIM project, which is funded by the Marie Skłodowska Curie Postdoctoral Fellowship programme, is using the state-of-the-art Regional Climate Model, RegCM5, to simulate the climate of the Circum-Sicilian islands for eight time periods between 21,000 years ago (last ice-age) and future global warming scenarios.

Researcher James Ciarlo'.

These simulations shed light on the role humanity has played in the ecological changes of these small islands and improve our understanding of past climate changes. The project will also provide new insights into possible future habitat changes for arthropods and potentially mitigate the destruction of these fragile ecosystems. The arthropod’s ability to adapt depends greatly on the number of pressures applied to them at the same time, such as rapid climate change coupled with habitat changes due to land development. It is envisaged that the loss of key species may heavily impact agriculture and the economy, while on the other hand, some species, often pests like the Tiger mosquito, are very quick to adapt and start spreading into new regions carrying diseases with them.

The PALEOSIM project will run until January 31, 2025.

For further information about this ongoing research, visit https://www.um.edu.mt/projects/paleosim.

FAQ

What is PaleoClimate? The term “paleo” is a Greek term meaning “ancient”. Paleoclimate or Palaeoclimate, describes ancient climates, such as the last ice age.

How are insects important to our ecosystem?

Insects (and all other arthropods) play vital roles in the ecosystem, and hence act as indicators of ecosystem integrity. That means they can help with things like population control of plants and other insects, pollination of plants, and decomposition of dead animal/plant material.

We hear a lot about climate change happening today. But what happened in the past?

During the last ice age (21,000 years ago) glaciers extended as far south as modern-day London, which caused sea levels in the Mediterranean to drop by more than 110 m (compared to today’s levels). As a result, Europe had a cooler climate, and Malta was a peninsula connected to Sicily, allowing animals (including insects) to spread down to Malta. As the ice age ended, the glaciers receded, sea levels rose, and Malta became isolated, drier, and warmer (similar to the climate our grandparents were used to).

What is a climate model?

A climate model is a computer program that represents the known atmospheric physics and chemistry in a virtual environment. These programs make use of power supercomputers to run simulations of our world’s climate. In these programs, the world map is divided into grid boxes. The size of these boxes determines how detailed a simulation will be, for example, grid boxes of 100x100km cannot adequately represent the complex terrain of Europe and the Mediterranean, but smaller boxes require significantly greater computational resources.

Regional Climate Models provide the possibility of studying a smaller region with much smaller grid-boxes. The current state-of-the-art climate models provide the possibility to use grid boxes of 3x3km.

The climate is continuously changing. How can scientists study the climate of the past? How far back? How accurate? What resolution?

The recent past can be studied by using the numerous types of meteorological observations taken from weather stations, weather balloons, aeroplane and ship readings, satellite data, and sometimes even hand-written data logs.

As we start looking further back in time, the sources of direct observations diminish. Beyond this point, we rely on indirect information from the world’s climate - these are called “proxy measurements”. Tree rings, sediments, stalactites & stalagmites, and glaciers are examples of natural sources for these “proxy measurements” as they “trap” information that has a strong relationship with the climate at the time of their formation. With these measurements, we can build a picture of past climates dating back millions of years.

This information however, is not equally spread across the globe, and does not describe every year in the past, and hence it is difficult to build a detailed picture of the climate of a complex region such as the Mediterranean with these tools alone.

Climate models provide a solution here as well, as we can apply modifications to the terrain and orbital conditions of our planet that correspond to the period of interest, and run a paleoclimate simulation.

How can man-made climate change influence the habitat of insects, and why does it matter?

All living organisms are adapted to a specific range of climate conditions and when this changes, the organisms must either adapt or move to a new area.

If this is not possible, then it's more than likely that they will go extinct in that area. This may add pressure to an already stressed environment. As an example, the Sand Cricket (Brachytrupes megacephalus) which lives in sandy areas, is already threatened due to habitat loss due to human interference.

The methods developed in PALEOSIM will give an indication of how climate change will impact the habitats of species like the Sand Cricket, as well as others like our wild bees.

James Ciarlo` is a climate change specialist using supercomputers to derive climate models on small regions (such as Europe). Following his PhD studies at the University of Malta, he spent 4 years working at the Abdus Salam International Centre for Theoretical Physics in Trieste, Italy where he was part of the research efforts that contributed to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change.

This article is edited by Christian Borg and brought to you by the Malta Chamber of Scientists https://mcs.org.mt.