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.
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.
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.
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.
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.
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.
“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.
“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.
By Prakash Khadka, IIASA Guest Research Assistant and Wei Liu, Guest Research Scholar in the IIASA Equity and Justice Research Group
Prakash Khadka and Wei Liu explain how unbridled, unplanned infrastructure expansion in Nepal is increasing the risk of landslides.
Worldwide, mountains cover a quarter of total land area and are home to 12% of the world’s population, most of whom live in developing countries. Overpopulation and the unsustainable use of these fragile landscapes often result in a vicious cycle of natural disaster and poverty. Protecting, restoring, and sustainably using mountain landscapes is an important component of Sustainable Development Goal 15 ̶ Life on Land ̶ and the key is to strike a balance between development and disaster risk management.
Nepal is among the world’s most mountainous countries and faces the daunting challenge of landslides and flood risk. Landslide events and fatalities have been increasing dramatically in the country due to a complex combination of earthquakes, climate change, and land use, especially the construction of informal roads that destabilize slopes during the monsoon.
According to Nepal government data, 476 incidents of landslides and 293 fatalities were recorded during the 2020 monsoon season – the highest number in the last ten years, mostly triggered by high-intensity rainfall – a trend which is increasing due to climate variations. According to one study, by mid-July 2020, the number of fatal landslides for the year had already exceeded the average annual total for 2004–2019.
Figure 1: A map of landslide events in Nepal from June to September 2020. Source: bipadportal.gov.np
Landslides are not a new phenomenon in the country where hills and mountains cover nearly 83% of the total land area. While being destructive, landslides are complex natural processes of land development. The Gangetic plain, situated in the foothills of the Himalayas, was formed by the great Himalayan river system to which soil is continually added by landslides and deposited at the base by rivers. Mountain land changes via natural geo-tectonic and ecological processes has been happening for millions of years, but fast population growth and climate change in recent decades substantially altered the fate of these mountain landscapes. Road expansion, often in the name of development, plays a key role.
Many mountain areas in Nepal are physically and economically marginalized and efforts to improve access are common. Poverty, food insecurity, and social inequity are severe, and many rural laborers opt to migrate for better economic opportunities. This motivates road network expansion. Since the turn of the century, Nepalese road networks has almost quadrupled to the current level of ~50 km per 100 km2, among which rural roads (fair-weather roads) increased more than blacktop and gravel roads.
Figure 2: Mountains carved just above Jay Prithvi Highway in Bajhang district of Sudurpaschim province to build a road
Nepalese mountain roads are treacherous and subject to accidents and landslides. Rural roads, which are often called “dozer roads”, are constructed by bulldozer owners in collaboration with politicians at the request of communities (also as part of the election manifesto in which politicians promised road access in exchange for votes and support to win), often without proper technical guidance, surveying, drainage, or structural protection measures. In addition, mountains are sometimes damaged by heavy earthmovers (so-called “bulldozer terrorism”) that cut out roads that lead from nowhere to nowhere, or where no roads are needed, at the expense of economic and environmental degradation. Such rapid and ineffective road expansion happens throughout the country, particularly in the middle hills where roads are known to be the major manmade driver of landslides.
To tackle these complexities, we need to rethink how we approach development in light of climate change. This has to be done with sufficient investigation into our past actions. The Nepalese Community forestry management program, which emerged as one of the big success stories in the world, encompasses well defined policies, institutions, and practices. The program is hailed as a sustainable development success with almost one-third of the country’s forests (1.6 million hectares) currently managed by community forest user groups representing over a third of the country’s households. Another successful example is the innovation of ropeways and its introduction in the Bhattedanda region South of Kathmandu. The ropeways were instrumental in transforming farmers’ lives and livelihoods by connecting them with markets. Locals quickly mastered the operation and management of the ropeway technology, which was a lifesaver following the 2002 rainfall that washed away the road that had made the ropeway redundant until then.
These two examples show that it is possible to generate ecological livelihoods for several households in Nepal without adversely affecting land use and land cover, which in turn contributes to increased landslide risk in the country, as mentioned above.
A rugged landscape is the greatest hindrance to the remote communities in a mountainous country like Nepal. It cannot be denied that the country needs roads that serve as the main arteries for development, while local innovations like ropeways can well complement the roads with great benefits, by linking remote mountain villages to the markets to foster economic activities and reduce poverty. Such a hybrid transportation model is more sustainable economically as well as environmentally.
It is a pity that despite strong evidence of the cost-effectiveness of alternative local solutions, Nepal’s development is still mainly driven by “dozer constructed roads”. Mountain lives and livelihoods will remain at risk of landslides until development tools become more diverse and compatible.
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.
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 .
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 .
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 . 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.
 IEA (2019). The Future of Cooling in China: Delivering on Action Plans for Sustainable Air Conditioning, International Energy agency (IEA), Paris.
 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]
 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).