This blog post details the creation of a “youtube-style” tutorial that could be used as a resource by teachers and GCSE students on the newly proposed GCSE in Natural History. The specific theme of the lesson is focused on climate change and the effect it is causing to the balance of our ecosystem. The lesson was developed by PhD students, who are part of the NERC funded GW4 FRESH CDT.
The GW4 FRESH CDT is a NERC (Natural Environment Research Council) funded Centre for Doctoral Training (CDT) in Freshwater Bioscience and Sustainability. The CDT brings together world class resources and training from the four Universities of Exeter, Bath, Cardiff and Bristol, to help equip the next generation of freshwater scientists. The CDT currently hosts 37 PhD students, researching a wide-range of topics from water-quality modelling to quantifying the impact of beaver reintroduction on freshwater ecology.
Every year as part of the CDT cohort training programme, we undertake a cross-skills challenge event. During these events we have the opportunity to develop our skill set in a topic of relevance to our education/career, but that is slightly outside the scope of our own research areas. This year the focus was on teaching skills, where we first received some expert tuition before being asked to split into small groups to prepare and then present a short lesson to the rest of our peers.
It was decided that the lessons should be based on themes related to the newly proposed GCSE in Natural History. As a group, we were very enthused to hear about the plans for this new GCSE and very jealous that we didn’t get the same opportunity when we were at secondary school. At a time where the connection with our natural world matters more than ever, where climate change is wreaking havoc with the environment and the economy, and nature-based solutions are becoming ever more necessary, this GCSE, we hope, would help inspire the next generation to tackle these present and future challenges.
The proposed themes for the new GCSE are highly relevant and I’m sure they will provoke many interesting class discussions. We are all PhD students with a keen interest in freshwater sustainability, but we also have a much wider passion for natural sciences and our group has a diverse range of graduate degrees within this field. We therefore welcomed the opportunity to be able to utilise this expertise and develop a learning resource for teachers and the younger generation who are looking to take a GCSE in Natural History. We hope that the lessons we have made will provide teachers and GCSE students with a wider view of their new themes in an easily accessible format and have a lasting impact. We were very pleased with the opportunity to have this public engagement outcome from our cross-skills challenge event and we hope to provide an example to younger students of what academic careers and activities are available to them in the field of Natural Sciences.
Our particular team chose the topic of climate change for our lesson. However, we decided to focus our message on viewing the world, and the ecosystems within it, as a precariously balanced system. Climate change is causing disruptions to the balance of this system and that generally leads to a chain of events that damages the function of the ecosystem. We felt that presenting the lesson from this perspective would leave a lasting and important message for students, that has implications for many areas of natural sciences. We also wanted to deliver the presentation in a format that was refreshing, quirky and memorable. After being inspired by another academic’s presentation, we decided to deliver the lesson as a pre-recorded video of a flip-book of hand-drawings, along with some ‘real-life’ outdoor footage. We were very conscious to keep the presentation very light on words, but tell the story through carefully designed drawings that would keep the viewer engaged. Based on the feedback we received from our peers we believe we achieved this objective. There is also a lot we have learnt from the experience and we will certainly try and incorporate this more engaging style of presenting in our own work.
Below is the video of our lesson and accompanying description, glossary and transcript. Due to limitations of my WordPress account, the video can’t be embedded – please click on the link below to find the video. The lesson was created by Dan Osmond, Costanza Zanghi and Tomo Homan – see a short profile section on each of us at the end of this blog. The blog was written by Tomo. We hope you find this resource useful.
This video is aimed at School Teachers to use during their classes as a support to learning or revision aid for students at GCSE level.
To take part in the interactive sections use tools such as slido (https://www.sli.do/ ), alongside the video or pause the video to allow in-class discussion.
Glossary
Algal Bloom: rapid growth and proliferation of microscopic algae due to optimal environmental conditions.
Atmosphere: layer of gasses surrounding a planet.
Convection currents: water movement in the ocean that is dependent on the temperature and density of the water. Cold and more dense (more salty) water is heavier than warm water, so it is found at the bottom of the ocean, close to the sediments. When this water gets pushed upwards, for example when it flows towards shallower areas, it gets closer to the surface and it warms up so it starts flowing as a top layer over the cold water.
Ecological feedback loop : how changes in one part of a system affect another, and in turn how these feed back to the original source of change.
Ecosystem: flora, fauna and their physical environment.
Emissions: the release into the atmosphere of greenhouse gasses, this can happen through natural processes such as volcanic activity, or by human activities like the burning of fossil fuels.
Fossilised: preserved animal and plant remains over geological eras.
Global processes: the interactions between two or more parts of an ecosystem.
Global warming: the rise of the average temperature of the Earth’s surface.
Greenhouse gasses: all the gasses involved in trapping heat into the atmosphere. These can be naturally or human-derived.
Phenology: The study of the timing of life cycle events in animals and plants.
Photosynthesis: the process happening inside plants and other organisms (like phytoplankton) where sunlight, carbon dioxide and water are transformed in oxygen and glucose – Glucose is a sugar needed for the plant growth.
Phytoplankton: microscopic algae.
Primary production: organisms responsible for the primary production are called primary producers, these are organisms (such as plants) that use compounds found in the atmosphere like CO2 and sunlight as a food source. They are the first link in the food chain as they are eaten by the secondary consumers and so on.
Sink (e.g. carbon sink): anything that absorbs more (carbon or heat) than what it emits. For example, carbon and heat is absorbed by the sea, and kept away from the atmosphere.
Upwelling: movement of cold and nutrient rich water from the depth of the ocean towards the surface.
Ocean stratification: is the phenomenon in which the water column develops two discrete layers of water of different temperatures: warm and less dense on top and cold and hence more dense waters below.
Transcript:
Hello everyone, today we want to talk about Climate Change. In the last couple of years lots of people have been talking about Climate Change, but what does it actually mean? How is the climate changing and how does it affect us? Before digging into the topic have a look at your chat box and follow the link you find there. Enter a few words that you associate most with “Climate Change”. With this word cloud we are building together a picture of what Climate Change means to us. During this lesson we are going to talk about the importance of BALANCE in the ecological processes happening on our planet, we will discuss how human activities are affecting this balance and then we will take a closer look to some of these processes. By the end of the lesson you should be able to describe what ecological feedback loops are, discuss which human activities impact the planet and how, and you should be able to link global processes to local events. Let’s go find out together how it all works. I always find it easier to learn about something new if we start by looking at the bigger picture. So we are going really big: Here is planet Earth, you may be familiar with it. Earth is a great system where all living things share spaces and try very hard to find BALANCE with the natural elements and this has been going on over thousands and thousands of years. The idea that planet Earth is a complex and INTERACTIVE system was introduced by a cool guy called James Lovelock, he is an English scientist and environmentalist who in the 1970s came up with this GAIA Theory basically saying that planet Earth works together with its biological inhabitants to SELF-REGULATE to maintain an environment that is
favourable to life. This works in the same way as when you go out for a walk and get too warm, you REGULATE your temperature by taking off your jumper, then when you cool down and start to feel chilly again, you may want to put that jumper back on. A very interesting way in which our planet does exactly that is through PHYTOPLANKTON. These are tiny unicellular algae which float in the oceans and although we can’t even see them with the naked eye, they produce 50% of all the oxygen we breathe! Well, these guys very much like the summer and when temperatures go up and they get a lot of sunshine they start to BLOOM, which means they multiply exponentially, so much that you can actually see them FROM SPACE! Beside oxygen production, phytoplankton is very important because it also releases into the atmosphere a very special gas called dimethyl sulfide DMS, and DMS is a key ingredient for making CLOUDS! And as we all know clouds are great, they shield the Earth’s surface from further solar irradiation while allowing extra heat from Earth to disperse into space. As the temperature cools down, phytoplankton blooms die off, we get some more lovely sunny days and the cycle starts all over again. This is what we call a FEEDBACK LOOP, where events are triggered one after the other with very little external intervention. Another example of a feedback loop is when you are bored and open the fridge door, remember you are actually not that hungry and anyway there is nothing you’d want to eat, close the fridge door, to do it all over again 15 min later. Now, the very important bit here is that when the planet gets too hot, cloud cover is important because it stops the Earth surface from overheating, by shielding some of the sun light and allowing heat from the surface to escape into space providing a very much needed cooling effect. Now this LOOP of cooling and warming has been going on planet Earth for a long long time, yet it can be disrupted. There are two key elements here that are at risk, one is the phytoplankton presence… if the phytoplankton is not there, no DMS and bye bye clouds. Why would phytoplankton not be there?? You may ask, well, human activities are impacting the oceans causing a lot of problems, we will talk about some of them later on in this lecture so stay tuned! The other risky element is found up in the atmosphere. GREEN-HOUSE GASSES found there act as a barrier THE OPPOSITE WAY of clouds, they let the heat in, but don’t let it out… you see where this is going… But let’s take a step back. What are greenhouse gasses? These are a lot of different compounds many of which are found naturally in the atmosphere, like carbon dioxide, methane and water vapour. The normal biological processes of all living things, plus stuff like volcanoes are natural sources of these gasses, and in fact, volcanic activity on early Earth is believed to have kick- started the building of the atmosphere we live in today! So a little greenhouse gasses is pretty good and technically what makes Earth a living planet and Mars a lot of cold rocks! THE PROBLEM is that since WE got involved, the level of greenhouse gasses in the atmosphere has gone through the roof!
Whilst this greenhouse effect is essential to sustain life on earth as we know it, our actions as societies can and have altered this balance. Much of our modern society has been built, beginning in the industrial revolution of the 1800’s, by the development of large-scale fossil fuels, including oil, coal and natural gases,
powering heavy industry. These fuels are made of the fossilised remains of plants and small animals, which have locked away the element carbon underground for millions of years, releasing this carbon into the earth’s atmosphere as the greenhouse gas carbon dioxide when these fuels are burned. Other human activities have introduced greenhouse gases to the atmosphere. Flourinated refrigerant gases (CFC’s, HFC’s and HCFC’s), commonly used in fridges, freezers and air conditioning, commonly leak when these appliances are thrown away. These refrigerant gases are many more times more potent than carbon dioxide, up to thirteen thousand times more potent per kilo of gas, have contributed to 11% of historic warming. Land use too has altered the balance of greenhouse gases in the atmosphere. Methane is produced in the gut of cattle during digestion and by anaerobic bacteria in paddies flooded for rice production. Methane is a powerful greenhouse gas, over 20 times more potent than carbon dioxide and is the second most influential driver of human induced climate change after CO2. The earth is now, on average, over one degree hotter than it was 150 years ago during pre-industrial levels. Temperatures have been rising rapidly as a result of rapidly increasing greenhouse gas emissions, with carbon dioxide levels increasing 100 times more quickly than during natural climatic cycles at the end of the last ice age and now at 417ppm in the atmosphere – the highest it has been for 4 million years. Global warming is now predicted by scientists to reach 1.5 degrees above pre-industrial levels, even with measures to reduce emissions, and will exceed two degrees within your lifetime if current trends do not change. We have already seen that the climate and global ecosystems interact and influence one another. How then will these changes to global temperatures and weather patterns impact ecosystems?
One area where climate change has a significant impact on our ecosystems is in our oceans. The ocean acts as a huge heat and carbon sink and plays an instrumental role in regulating our climate. Oceans help regulate atmospheric CO2 concentrations. CO2 is absorbed in cooler waters and released in warmer waters, but most importantly phytoplankton take CO2 out of the atmosphere during photosynthesis and produce oxygen for the air that we breathe. This organic carbon then gets stored in the food chain and as animals die and decay becomes buried in deep sea sediments. In total the oceans absorb about 25% of the CO2 we produce, which is equivalent to the amount of carbon that would be stored in a hundred and fifty billion trees. The oceans also have the capacity to absorb a lot of heat. In fact since the 1970s the oceans have absorbed more than 90% of the excess heat energy trapped by greenhouse gases (equivalent of 5 nuclear bombs exploding every second since 1990). This has raised the sea surface temperature by 0.13 degC per decade over the last 100 years, which may not seem like much, but it is hugely significant. Without the oceans absorbing this excess heat the earth would be approximately 36 degC hotter. One effect of warmer oceans is Coral bleaching. Coral are extremely sensitive to temperature rises and an increase of just one degree celsius can cause them to bleach – meaning they spit out the algae that live inside them, which not only gives coral those vibrant colours, but also provides them with much of their energy. Coral reefs are often referred to as the rainforests of the
ocean supporting a diverse ecosystem and home to an estimated 25% of all marine species. Heavily bleached or damaged coral reefs resemble a ghost town. As we have seen, the ocean plays a vital role in mitigating the effects of climate change through acting as a carbon and heat sink. As Co2 emissions continue to rise this risks upsetting this delicate balance. Further Co2 emissions will result in further ocean warming. A warmer ocean reduces convection currents as warmer and hence less dense surface waters will sit on top of denser cooler waters. This is known as stratification. This warmer stagnant layer will have a reduced capacity for absorbing O2 and CO2, which will result in more CO2 in the atmosphere and therefore more global warming creating a positive feedback loop. Stratification will also prevent the upwelling and mixing of nutrient rich waters from below, supporting fewer phytoplankton at the surface. Again further reducing the amount of CO2 that can be absorbed by the ocean. Phytoplankton are primary producers and so a reduction in their numbers will have a knock on effect for the entire food chain. All these changes will alter the distribution, abundance and productivity of many marine species.
On land, the stability of our ecosystems is also very sensitive to climate change. To understand how, we first need to learn a few definitions: What is phenology? Phenology is the study of the timing of life cycle events and how are plants and animals respond to the weather and climate. Can you think of any changes that occur in our natural world as we go through the seasons? A Phenological mismatch occurs when the interacting species change the timing of their regularly repeated life cycle events at different rates in response to a change in climate. To understand this better we will look at a specific example of the relationship between blue tits, caterpillars and oak trees: The favourite food of blue tit chicks are caterpillars, with some eating up to 100 in a day. The caterpillars love to munch on oak tree leaves. Ordinarily oak tree leaves start to open around the end of April and in to May. The caterpillars that feed on the oak tree leaves appear soon afterwards and the Blue tit time their breeding in April so the hatching of the chicks coincide with the abundant food supply of caterpillars. However, climate change is causing spring to arrive earlier causing trees and flowers to bloom earlier. The caterpillars also appear earlier as oak trees and caterpillars have similar sensitivities to temperature increase. However, the blue tits don’t have the same capacity to rapidly adapt and so more and more blue tit chicks are hatching too late when the food supply is diminished and unfortunately this means that more and more broods are failing. Since 1999, spring has arrived, on average, 6 days earlier than in the first part of the 20th century. This may not seem like much, but within the intricately balanced life cycle of our wildlife this can make a big difference. Another example is our mountain hares in Scotland that moult from a dark coat in summer to a white coat in winter so they maintain camouflage against snowy landscapes. However climate change is causing milder winters and earlier springs, meaning that there are less snowy days and earlier snowmelt. This creates a mismatch for our mountain hares seasonal camouflage, making them more exposed to predators such as birds of prey and changing the dynamic of the ecosystem. It’s not necessarily all doom and gloom though. Climate change for some species presents an opportunity. Milder winters in the UK are
causing some species of birds, such as the blackcap and chiffchaff, to over winter in the UK rather than migrate south. The blackcap is already showing signs of adapting their feeding habits to exploit human-provisioned food in gardens. Those that don’t migrate see an increase in fitness and there is evidence to suggest that blackcaps wintering in Britain fledge more chicks. The species that can adapt the quickest to the changing climate will be the most successful.
Profiles
Tomo Homan – NERC FRESH PhD Student, University of Bath
I am in the second year of my PhD, based at the University of Bath. My research is focused on developing a high temporal and spatial resolution in-stream fate and transport model of key water quality pollutants of concern. The model will then be used to investigate the high resolution dynamics of the system, to understand where and when the greatest risks occur and to inform the most appropriate management decisions. The catchment area I am focused on is the Frome and Piddle catchment in Dorset, where elevated nitrate and phosphate levels cause issues associated with excessive plant and algal growth in areas of important nature conservation value. I also have a keen interest in emerging contaminants that are entering our waterways such as pharmaceuticals and pesticides, that have been shown to subtly change the behaviour and population dynamics of our freshwater organisms. I would like to apply the model to better understand the risks of these contaminants also, as well as the impact of sewage storm overflows on river ecology. I have a MEng in Biochemical Engineering from the University of Bath.
Daniel Osmond – NERC FRESH PhD Student, University of Exeter and Game and Wildlife Conservation Trust.
My PhD research focusses upon understanding how the commonly distributed freshwater fish, the brown trout, responds and adapts to a post-industrial legacy of heavy metal pollution within our rivers. Present across much of the UK, from upland acidic tarns of the highlands to lowland chalkstreams in Southern England, brown trout have also been seen to persist and apparently continue to thrive in severely toxic metal polluted environments. Utilising whole genome sequencing of metal impacted populations across the British Isles, we can understand the impacts of this pollution on population structure and genetic health, and identify putative functional pathways responsible for metal adaptation.
Costanza Zanghí – NERC GW4 FRESH PhD Student, University of Bristol
Through my research I aim to observe and quantify changes in fish behaviour due to environmental change. Specifically I am interested in predator-prey interactions and see how the combined effect of multiple stressors such as increased temperature and turbidity affects anti-predator behaviour in prey and foraging behaviour in predators. To do so, I design laboratory experiments where I manipulate the environmental variables and observe how fish respond to the change, while I also set-up cameras in rivers and lakes to observe the foraging behaviour of fish in the wild. From previous research we know that warmer temperature affects fish in several ways, primarily it causes their metabolism to speed up, so fish need to forage more to stay fit and maintain good energy levels. At the same time higher temperature affects the speed of fish movement through the water, usually resulting in fish being more active and prey more conspicuous to predators. When this is coupled with increased turbidity, some fish predator may have more difficulties in securing prey as turbidity acts as a visual barrier in the water. It is important to understand how these stressors interact with each other because ecosystems are being subject to them simultaneously and their interaction could tip the balance of an ecosystem with negative consequences for biodiversity and wildlife.
PhD Life - Watered Down 