Warming waters, evolution, and the future for fisheries policy

By Neema Tavakolian, 2021 IIASA Science Communication Fellow 

Young Scientists Summer Program (YSSP) participant Lyndsie Wszola explores how human interactions with warming freshwater systems have affected the evolution of fish species through the lens of the North American walleye. 

© Justinhoffmanoutdoors | Dreamstime.com

The effects of climate change have intensified over the past few years, especially in our oceans, and human based activities contributing to it are now being taken more seriously. While the warming of our oceans is indeed troubling, many forget that freshwater systems are also being influenced, and that this is affecting the growth and evolution of the species that reside in them.

2021 YSSP participant Lyndsie Wszola wants to explore changes in freshwater systems using human-natural modeling systems at IIASA.

© Lyndsie Wszola

Growing up with a conservation officer father, Wszola is a second-generation conservationist. Knowing she wanted to enter this field at an early age, she realized that she had to get into research and academia first. Her main interests while studying at the University of Nebraska have been the interactions between humans and wildlife.

While researching the relationships between hunters and ring-necked pheasants, she discovered an affinity for quantitative research. This curiosity went even further after she discovered literature on harvest induced evolution and mathematical ecology specifically pertaining to fish populations. Together, this initial desire to explore human and wildlife interactions and her newfound interest in mathematical ecology, led Wszola to take a closer look at North American freshwater systems and how we as humans are influencing its ecology. Her research specifically delves into the growth and evolutionary changes seen in the North American walleye (Sander vitreus) – a popular fish in Canada and the United States. The reason for its fame is its palatable taste as a freshwater fish and its status among anglers, making it both a commercially and recreationally fished species.

Walleye was chosen as the subject of Wszola’s research for many reasons. First, walleye, like many fish, are ectotherms meaning that their body processes and behaviors are directly linked to their body temperature, which is in turn directly linked to the temperature of the water. Unlike other fish however, there is already plenty of research and data on the relationship between the walleye’s growth and temperature. This information makes it much easier to simulate the walleye’s eco-evolutionary growth dynamics in the context of human driven harvests in warming waters. Wszola will also be working with very large datasets spanning multiple latitudes ranging from Ontario, Canada down to Nebraska, USA. The datasets include up to six million fish with four million of those being walleye.

“My goal is to model the influence of temperature on fish harvests based on size. Due to their ectotherm nature, we can observe the changes in body size in annual harvests. As waters warm, walleye grow much faster. We also know that intensely harvested fish often evolve to reach maturation at smaller sizes. When coupled with rising temperatures, this relationship between harvest induced and temperature induced evolution can be fascinating, as we now have two sources working together to change the growth evolution of this fish,” she explains.

Due to warming temperatures, many natural resources are at stake with some of the most sensitive being aquatic in nature. Research like this is important as it allows us to look at our relationships with the environment to be able to react accordingly.

“I hope that the research I do yields fascinating enough results so that from a practical standpoint, future fisheries policies can include climate change dynamics in addition to fish and human dynamics,” Wszola concludes.

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Science across closed borders – the quest for restoring forests in North Korea

By Fanni Daniella Szakal, 2021 IIASA Science Communication Fellow

Despite the political challenges, 2021 YSSP participant Eunbeen Park is researching ways to restore forests in isolated North Korea.

© Znm | Dreamstime.com

North Korea is somewhat of an enigma and getting a glimpse into what transpires behind its borders is a difficult task. Based on our limited information, it however seems that its once luscious forests have disappeared at an alarming rate in the last few decades.

Deforestation in North Korea is fueled by economic difficulties, climate change, and a lack of information for effective forest management. As forests are recognized as important carbon sinks that are invaluable when working towards the climate goals established in the Paris Agreement, finding a way to restore them is imperative. Forests are also essential in solving food insecurity and energy issues, which is especially relevant in the face of the current economic hardship in North Korea.

Neighboring South Korea serves as a benchmark for a successful reforestation campaign after having restored most of its forest cover in the last half a century. South Korean researchers and NGOs are keen to support afforestation efforts in North Korea and it seems that the North Korean government is also prioritizing this through a 10-year plan announced by North Korean leader Kim Jong-Un in 2015. The strained relationship between the two Koreas however, often hinders effective collaboration.

‘’We are close to North Korea regionally, but direct connection is difficult for political reasons. However, many researchers are interested in studying North Korea and there are currently many projects for South and North Korea collaboration supported by the Ministry of Unification,” says Eunbeen Park, a participant in the 2021 Young Scientists Summer Program and a second year PhD student in Environmental Planning and Landscape Architecture at Korea University in Seoul, South Korea.

North Korean countryside © Znm|Dreamstime.com

Modeling afforestation scenarios in North Korea

Park specializes in using remote sensing data for environmental monitoring and detecting changes in land cover. During her time at IIASA, she will use the Agriculture, Forestry, and Ecosystem Services Land Modeling System (AFE-LMS) developed by IIASA to support forest restoration in North Korea.

First, Park will use land cover maps dating back to the 1980s to map the change in forest cover. She will then identify areas for potential afforestation considering land cover change, forest productivity, climate, and different environmental variables, such as soil type. She will also develop different afforestation scenarios based on forest management options and the tree species used.

According to Andrey Krasovskiy, Park’s supervisor at IIASA, when selecting tree species for afforestation we need to take into account their economic, environmental, and recreational values.

“From a set of around 10 species we need to choose those that would be the most suitable in terms of resilience to climate change and to disturbances such as fire and beetles,” he says.

Challenges in data collection

A major challenge in Park’s research is obtaining accurate information for building her models. If there is relevant research from North Korea, it is not available to foreign researchers and without being able to enter the country to collect field data in person, her research has to rely on remote sensing data or data extrapolated from South Korean studies.

Fortunately, in recent years, remote sensing technology has evolved to provide high-resolution satellite data through which we are able to take a thorough look at the land cover of the elusive country. Park will match these maps with yield tables provided by Korea University based on South Korean data. As the ecology of the two Koreas are largely similar, these maps are thought to provide accurate results.

Is there space for science diplomacy?

“Research shouldn’t have any boundaries,” notes Krasovskiy. “In reality however, the lack of scientific collaboration between research groups in South and North Korea poses a major obstacle in turning this research into policy. Luckily, some organizations, such as the Hanns Seidel Foundation in South Korea, are able to bridge the gap and organize joint activities that provide hope for a more collaborative future.”

Despite the diplomatic hurdles, Park hopes that her work will find its way to North Korean policymakers.

“I expect my research might make a contribution to help policymakers and scientific officials establish forest relevant action in North Korea,” she concludes.

Can seaweed be the solution to our land problems?

By Neema Tavakolian, 2021 IIASA Science Communication Fellow

Young Scientists Summer Program (YSSP) participant Scott Spillias explores how the adoption of offshore seaweed farming could affect land use.

Seaweed farming in the clear coastal waters of Zanzibar island © Ecophoto | Dreamstime.com

Since the start of the industrial revolution, the Earth’s population has grown exponentially, and it is still growing every year. In addition to heavy population growth, human advances in medicine, science, and technology have allowed people to live longer lives as well. As more countries industrialize, the demand for land extensive commodities like meat and dairy have also increased. Deforestation has risen worldwide making way for cattle and other livestock grazing, and more of the food we grow is being dedicated towards livestock rather than human consumption.

With problems like unsustainable land use, climate change, and suburban sprawls in places like the United States and Australia decreasing available arable lands, this poses the question: is there any way we can feed a growing population without further damaging ecosystems and contributing to climate change? In addition to achieving this goal, we simultaneously want to promote equitable and just societies. 2021 YSSP participant Scott Spillias believes he might have a solution: seaweed.

Spillias has a background in marine biology and sailing. After years of sailing the world, he could see the alarming state of our oceans. Wanting to be part of the solution, he moved to Australia to study oceanic food systems, environmental economics, and environmental decision making at the University of Queensland.

Scott Spillias © Scott Spillias

“We live on an ocean planet, yet almost all of the food we grow comes from land. When it comes to the sea, we are essentially just unsustainably hunting and gathering from our oceans. I want to know what it would look like if instead, we tried to farm them,” Spillias explains.

Spillias says that seaweed as an agricultural product is already useful with its range of uses including food, livestock feed, fuel, fertilizer, and multiple products in the form of hydrocolloids. Hydrocolloids, more commonly known as “gums”, are extracted from plants like seaweeds and algae; they are used as setting and thickening agents in a variety of products including foods and pharmaceuticals, often increasing shelf life and quality.

A University of California, Davis study found that incorporating seaweed in cattle feed could reduce methane emissions from beef cattle by as much as 82%. Moreover, seaweed’s broad range of uses can hypothetically decrease land usage in favor of sea usage. Seaweeds also serve many ecological roles such as filtering ocean waters, serving as nurseries for small fish and crustaceans, and protecting sea floors.

There are two types of seaweed farming in use today. In parts of China, South Korea, and Japan there is floating offshore seaweed production, where the seaweed is grown and harvested while floating in deep waters. Another form of seaweed farming seen in Indonesia, Tanzania, and the Philippines involves a different approach, where the seaweed is grown and farmed closer to the coast in shallower waters, or the intertidal zone. Both provide ecosystem services, jobs, and food for local populations.

As part of his YSSP project this summer, Spillias hopes to use the IIASA Global Biosphere Management Model (GLOBIOM) to determine land-use changes brought about by large-scale seaweed production.

“We are going to assume that the seaweeds we are growing will be for food, feed, and fuel. We are also taking certain constraints into consideration, such as the inability to place seaweed farms in high traffic shipping areas or marine protected zones. Getting rough estimates of seaweed production can then give us an idea of land commodities we can replace, for instance, corn used for biofuel,” he says.

Spillias hopes that this research can provide results that can influence policy.

“Locally, seaweed farming will either be beneficial or destructive – it depends on where you put it and how you do it. Zooming out and understanding how these tradeoffs relate to terrestrial production will give policymakers a clearer idea of whether to promote or restrict the practice.”

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Matching human movement to climate change

By Greg Davies-Jones, 2020 IIASA Science Communication Fellow

Greg Davies-Jones sits down with 2020 IIASA Young Scientists Summer Program (YSSP) participant Lisa Thalheimer to discuss how attribution science can play a leading role in addressing disaster displacement.

We live in the era of the greatest human movement in recorded history – there are more people on the move today than at any other point in our past. Despite the common misconception that most migrants cross borders, a lot of migration actually occurs internally. According to the Internal Displacement Monitoring Center, a staggering 72% of internal migration is linked to displacement due to natural hazards or extreme weather.

Pinpointing the finer details of how human mobility might evolve remains a complex undertaking. Contemporary migratory movements reflect the complex patterns of social and economic globalization – they flow in all directions and affect all countries in one way or another. It is clear that given the rising global average temperatures, natural hazards and extreme weather events will increase in frequency, intensity, and duration, adversely effecting many parts of the globe. A better understanding of how human-induced climate change influences disaster displacement will undoubtedly be essential in addressing future human mobility and informing the debate on climate and migration policies.

Figure: Climate-related displacement on an axis of forced to voluntary human mobility. Thalheimer (2020)

 

The focus of 2020 YSSP participant Lisa Thalheimer’s research is on internal displacement in East Africa, in particular, Somalia. As part of her YSSP project, Thalheimer hopes to determine whether, and to what extent, human-induced climate change altered the likelihood of extreme weather-related displacement in Somalia by conflating econometric methods and Probabilistic Event Attribution (PEA).

“Econometrics is essentially the application of statistical methods to quantify impacts and PEA is a way of examining to what extent extreme weather events can be linked with past man-made emissions. By combining the two methods we hope to quantify the ramifications of extreme weather and displacement in East Africa,” she explains.

This is no mean feat, as PEA itself is a relatively new science and many challenges still exist in the field of event attribution  ̶  a field of research concerned with the process by which the causes of behavior and events can be explained. In this instance, the idea was to study each extreme weather event individually to determine if human-induced climate change may have added to the intensity or likelihood of the event occurring. PEA is a growing science within this field and relies on the availability of long-term meteorological observations and the reliability of climate model simulations. In terms of migration and the accompanying econometric methods, the complexity of this work is mainly in data capturing.

“The difficulty with migration data capturing is at the start – before you can capture anything, you must ascertain how the data is defined, as different countries define mobility in different ways. For instance, it could be time – where did you live one year ago as opposed to five years ago? That’s the first complexity. Then you must work out who collects data on who – in Europe, we have fundamental freedom of movement within the EU, so unless you file for residency, your movement is not recorded. Another complexity is because we want to see if climate change is part of the driver  ̶  directly or indirectly. We need to know not just where people are now, but where they have been and where they came from, so we can match the climate with their movements. All of this highlights how difficult it is to carry out this type of analysis,” Thalheimer adds.

In Somalia, the team relied on previously collected forced migration data, for example, from the UN High Commissioner for Refugees (UNHCR). These UNHCR datasets collected in Somalia were comprehensive and included not only origin and destination information but also a categorization of the primary reason for the displacement.

© Aleksandr Frolov | Dreamstime.com

The investigation homed in on one extreme weather case study in the region: The April 2020 heavy rainfall in Southern Ethiopia, which led to several severe flooding events in South Somalia. In this particular case, however, no appreciable connection could be made between human-induced climate change and the resultant displacement. Despite this somewhat chastening outcome, the achievement of this study is not proving a definitive attributable link between human-induced climate change and the April 2020 rainfall, but rather the construction of the adjustable attribution framework presented that can be applied directly to other events and displacement contexts.

As previously mentioned, there are, however, limitations to this novel methodology, especially in regions like Somalia that lack exhaustive observational weather and displacement data. According to Thalheimer, exploring ways of effectively applying this framework in countries vulnerable to climate change will be particularly important going forward.

“Event attribution studies do not usually form the basis of climate migration analysis, disaster risk reduction, or adaptation strategies. Yet, to respond appropriately to these impacts and affected populations, we must develop a comprehensive and detailed understanding of the nature of these impacts, as well as knowledge on how these might evolve over time. Event attribution is a tool we can employ to do this,” she concludes.

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Exploring co-benefits of green cooling in China

By Xu Wang, IIASA Young Scientists Summer Program (YSSP) alumnus and Assistant Professor at Beijing University of Technology and Pallav Purohit, researcher in the IIASA Air Quality and Greenhouse Gases Program.

Xu Wang and Pallav Purohit write about their recent study in which they found that accelerating the transition to climate-friendly and energy-efficient air conditioning in the Chinese residential building sector could expedite building a low-carbon society in China.

© Shao-chun Wang | Dreamstime.com

China saw the fastest growth worldwide in energy demand for space cooling in buildings over the last two decades, increasing at 13% per year since 2000 and reaching nearly 400 terawatt-hours (TWh) of electricity consumption in 2017. This growth was largely driven by increasing income and growing demand for thermal comfort. As a result, space cooling accounted for more than 10% of total electricity growth in China since 2010 and around 16% of peak electricity load in 2017. That share can reach as much as 50% of peak electricity demand on extremely hot days, as seen in recent summers. Cooling-related carbon dioxide (CO2) emissions from electricity consumption consequently increased fivefold between 2000 and 2017, given the strong reliance on coal-fired power generation in China [1].

In our recent publication in the journal Environmental Science and Technology, we used a bottom-up modeling approach to predict the penetration rate of room air conditioners in the residential building sector of China at the provincial level, taking urban-rural heterogeneity into account. Our results reveal that increasing income, growing demand for thermal comfort, and warmer climatic conditions, could drive an increase in the stock of room air conditioners in China from 568 million units in 2015 to 997 million units in 2030, and 1.1 billion units in 2050. In urban China, room air conditioner ownership per 100 households is expected to increase from 114 units in 2015 to 219 units in 2030, and 225 units in 2050, with slow growth after 2040 due to the saturation of room air conditioners in the country’s urban households. Ownership of room air conditioners per 100 households in rural China could increase from 48 units in 2015 to 147 units in 2030 and 208 units in 2050 [2].

The Kigali Amendment to the Montreal Protocol on Substances that Deplete the Ozone Layer will help protect the climate by phasing down high global warming potential (GWP) hydrofluorocarbons (HFCs), which are commonly used as refrigerants in cooling technologies [3]. Promoting energy efficiency of cooling technologies together with HFC phase-down under the amendment can significantly increase those climate co-benefits. It is in this context that we assessed the co-benefits associated with enhanced energy efficiency improvement of room air conditioners (e.g., using efficient compressors, heat exchangers, valves, etc.) and the adoption of low-GWP refrigerants in air conditioning systems. The annual electricity saving from switching to more efficient room air conditioners using low-GWP refrigerants is estimated at almost 1000 TWh in 2050 when taking account of the full technical energy efficiency potential. This is equivalent to approximately 4% of the expected total energy consumption in the Chinese building sector in 2050, or the avoidance of 284 new coal-fired power plants of 500 MW each.

Our results indicate that the cumulative greenhouse gas mitigation associated with both the electricity savings and the substitution of high-GWP refrigerants makes up 2.6% of total business-as-usual CO2 equivalent emissions in China over the period 2020 to 2050. Therefore, the transition towards the uptake of low-GWP refrigerants is as vital as the energy efficiency improvement of new room air conditioners, which can help and accelerate the ultimate objective of building a low-carbon society in China. The findings further show that reduced electricity consumption could mean lower air pollution emissions in the power sector, estimated at about 8.8% for sulfur dioxide (SO2), 9.4% for nitrogen oxides (NOx), and 9% for fine particulate matter (PM2.5) emissions by 2050 compared with a pre-Kigali baseline.

China can deliver significant energy savings and associated reductions in greenhouse gas and air pollution emissions in the building sector by developing and implementing a comprehensive national policy framework, including legislation and regulation, information programs, and incentives for industry. Energy efficiency and refrigerant standards for room air conditioning systems should be an integral part of such a framework. Training and awareness raising can also ensure proper installation, operation, and maintenance of air conditioning equipment and systems, and mandatory good practice with leakage control of the refrigerant during the use and end-of-life recovery. Improved data collection, research, and cooperation with manufacturers can equally help to identify emerging trends, technology needs, and energy efficiency opportunities that enable sustainable cooling.

References:

[1] IEA (2019). The Future of Cooling in China: Delivering on Action Plans for Sustainable Air Conditioning, International Energy agency (IEA), Paris.

[2] Wang X, Purohit P, Höglund Isaksson L, Zhang S, Fang H (2020). Co-benefits of energy-efficient air conditioners in the residential building sector of China, Environmental Science & Technology, 54 (20): 13217–13227 [pure.iiasa.ac.at/16823]

[3] Purohit P, Höglund-Isaksson L, Dulac J, Shah N, Wei M, Rafaj P, Schöpp W (2020). Electricity savings and greenhouse gas emission reductions from global phase-down of hydrofluorocarbons, Atmospheric Chemistry and Physics, 20 (19): 11305-11327 [pure.iiasa.ac.at/16768]

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis (IIASA).