Extending the human footprint: greening as a hidden contributor to climate change

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Carbon dioxide and other greenhouse gases (GHGs) are not the only causes of climate change. We propose to assess the neglected effect of the 'greening' of lakes and oceans due to pollution (i.e. eutrophication) on the earth-atmosphere energy balance. Our main hypothesis is that greening exacerbates warming and weather events. If proven, this effect means that nutrients should be considered alongside GHGs in defyining the human footprint on climate, potentially leading to a paradigm shift in climate policy. The project aims to explore the correlation between the greening of lakes and oceans (eutrophication) and the earth-atmosphere energy balance. ContextThe primary driver of weather is the sun. However, it is primarily the response of the Earth's surface that generates climate dynamics. Without local variations in irradiation - determined by earth rotation, terrain morphology, water movements - the processes necessary to set into motion the mass of air above us (surface heating differences, evaporation, updrafts, clouds, winds, rain, etc.), would not occur. The atmosphere, with its humidity and composition, plays an addotional role, reflecting significant portions of the heat that the Earth's surface, like any warm body, emits to outer space. CO2, along with methane and other greenhouse gases (GHGs), plays an important part in this process by trapping and redirecting the infrared radiation (IR) emitted by the ground back towards the Earth. However, emissions of CO2 and other GHGs into the atmosphere are not the only human impact on climate change. Urbanisation, deforestation, etc., are additional factors that alter the thermal map of the ground and the climatic balance. There is, however, another factor that is probably undermining climate stability and might be even more impactful. Industrial development and food production (e.g. agriculture and animal farming) to meet the demands of the growing human population have dramatically increased the release of nutrients such as nitrogen and phosphorus into lakes and seas worldwide, causing widespread eutrophication. NoveltySo far, eutrophication has mainly been considered for its effects on aquatic environments. Nutrients occurring in fertilizers, animal waste and human waste, especially nitrogen and phosphorus, have severely impacted vast aquatic habitats on Earth over the last fifty years. This is, for instance, evident in the state of several Swiss lakes, which show algal blooms, fishery losses, and deoxygenation, as well as all coastal areas affected by urbanisation, intensive agriculture or animal farming, such as the Romagna Riviera and the Gulf of Naples. On a much larger scale, other areas affected are the Gulf of Mexico, the Baltic Sea, and Chesapeake Bay on the Atlantic coast of the USA.The effects of eutrophication are not confined to aquatic habitats. From another perspective, eutrophication and the consequent algal growth can alter the energy exchanges between the hydrosphere and the atmosphere, thus influencing the climate.The “greening” of the surface layers of lakes and seas caused by algal growth prevents solar radiation from penetrating deeply into the water column. The energy that would normally spread over tens of meters in a transparent (blue) water column is concentrated into the surface layers, substantially raising their temperature and increasing evaporation at the water-air interface. We hypothesize that these green areas create thermal currents charged with humidity, which inevitably draw in air masses from colder regions, causing increasingly intense weather events. The scientific literature has surprisingly neglected the potential relationship between eutrophication and atmospheric events. However, the energy involved is potentially massive, because we estimated that the increase in evaporation produced by a 1°C rise of the ocean’s surface has a GHG effect equivalent to that of 25% of the annual global CO2 emissions. AimsThe proposed project aims to develop a new interdisciplinary research and conduct an innovative study into the linkages between agri-food production and human population on one side and weather events on the other side. Thanks to the support of Innovation Booster Energy Lab, we will focus on two key correlations: (1) the correlation between water-surface colour (‘greening’) and water-surface temperature, and (2) the subsequent correlation between water and the air overhead in terms of heat exchange and evaporation. The analyses will be based mainly on data from Switzerland and northern Italy, as well as on a review of the literature related to eutrophication in general. The proposed research will be groundbreaking: the results, in addition to contributing to a better understanding of our biosphere, could susbtantially expand policy approaches to tackle climate change. Future developmentsIn the future, to complete our vision, we would like to analyse data on sea surface temperatures and eutrophication levels, inferred based on sea and lake colour data from satellite images, superimposed with information on the density of zootechnical and ichthyocultural installations, to analyse the links between food production and greening. Mapping the effects of the agri-food system, both in terms of plant and animal food production, in relation to eutrophication and linking it to climate change could become, like measuring CO2, a fundamental parameter for developing a new concept of sustainability. SignificanceIf the coupling between greening and weather events is supported, the effects of the agri-food production (through nutrient inputs or eutrophic load) should be considered alongside those of CO2 and other GHGs, adding a fundamental parameter for developing a new concept of human footprint on climate (e.g., a “eutrophication label”). Timeline 0-4 months: Analysis of selected Swiss and Italian lakes (case studies) to examine the association between surface colour and surface water temperature4-8 months: Simulation of the effects of water temperature on air temperature and evaporation using numerical models8-12 months: Disseminating the findings to different educational levels, fostering public awareness of the complex interconnections between human activities, eutrophication, and climate changeFuture: Developing a model with weighted parameters; expand the research trough research calls, Foundations, Governmental entities, Universities and Enterprises associations. TeamPaolo Giorgetti, lecturer researcher at SUPSI; aerospace systems engineer; expert in systems approaches and member of the technical secretary of the AQST (Environmental protection of Lake Varese).Camilla Capelli, Hydrobiologist; researcher in the Freshwater Ecology Group of SUPSI; expert in phytoplankton ecology, in particular algal blooms and the environmental factors that favour their proliferation in lake systems; satellite data analystCristina Carcano, Communication lecturer at SUPSI; member of Startup Garage SUPSI; Communication consultantFabio Lepori, Head of SUPSI's Freshwater Ecology Team. Researcher, lecturer and consultant in lake ecology and stream ecology; expert on lake eutrophication and the effects of climate change, with a focus on Lake LuganoFederica Rotta, Hydrobyologist; PhD student in the Freshwater Ecology Group of SUPSI, with expertise in the monitoring of plastic pollution in freshwater ecosystemsDaniele Strigaro, geo-informatics; researcher in the Geomatic group at SUPSI; expert in developing custom monitoring systems for sensing the environment and in analyzing and managing weather and climatic data.

Project Idea Metadata

• Project Idea Name: Extending the human footprint: greening as a hidden contributor to climate change
• Date: 8/15/2023 4:36:56 PM
• Administrators:
  • paolo giorgetti

Project Idea Description

The project aims to explore the correlation between the greening of lakes and oceans (eutrophication) and the earth-atmosphere energy balance.

Context

The primary driver of weather is the sun. However, it is primarily the response of the Earth's surface that generates climate dynamics. Without local variations in irradiation - determined by earth rotation, terrain morphology, water movements - the processes necessary to set into motion the mass of air above us (surface heating differences, evaporation, updrafts, clouds, winds, rain, etc.), would not occur.

The atmosphere, with its humidity and composition, plays an addotional role, reflecting significant portions of the heat that the Earth's surface, like any warm body, emits to outer space. CO₂, along with methane and other greenhouse gases (GHGs), plays an important part in this process by trapping and redirecting the infrared radiation (IR) emitted by the ground back towards the Earth.

However, emissions of CO₂ and other GHGs into the atmosphere are not the only human impact on climate change. Urbanisation, deforestation, etc., are additional factors that alter the thermal map of the ground and the climatic balance. There is, however, another factor that is probably undermining climate stability and might be even more impactful. Industrial development and food production (e.g. agriculture and animal farming) to meet the demands of the growing human population have dramatically increased the release of nutrients such as nitrogen and phosphorus into lakes and seas worldwide, causing widespread eutrophication.

Novelty

So far, eutrophication has mainly been considered for its effects on aquatic environments. Nutrients occurring in fertilizers, animal waste and human waste, especially nitrogen and phosphorus, have severely impacted vast aquatic habitats on Earth over the last fifty years. This is, for instance, evident in the state of several Swiss lakes, which show algal blooms, fishery losses, and deoxygenation, as well as all coastal areas affected by urbanisation, intensive agriculture or animal farming, such as the Romagna Riviera and the Gulf of Naples. On a much larger scale, other areas affected are the Gulf of Mexico, the Baltic Sea, and Chesapeake Bay on the Atlantic coast of the USA.

The effects of eutrophication are not confined to aquatic habitats. From another perspective, eutrophication and the consequent algal growth can alter the energy exchanges between the hydrosphere and the atmosphere, thus influencing the climate.

The “greening” of the surface layers of lakes and seas caused by algal growth prevents solar radiation from penetrating deeply into the water column. The energy that would normally spread over tens of meters in a transparent (blue) water column is concentrated into the surface layers, substantially raising their temperature and increasing evaporation at the water-air interface. We hypothesize that these green areas create thermal currents charged with humidity, which inevitably draw in air masses from colder regions, causing increasingly intense weather events. The scientific literature has surprisingly neglected the potential relationship between eutrophication and atmospheric events. However, the energy involved is potentially massive, because we estimated that the increase in evaporation produced by a 1°C rise of the ocean’s surface has a GHG effect equivalent to that of 25% of the annual global CO2 emissions.

Aims

The proposed project aims to develop a new interdisciplinary research and conduct an innovative study into the linkages between agri-food production and human population on one side and weather events on the other side. Thanks to the support of Innovation Booster Energy Lab, we will focus on two key correlations: (1) the correlation between water-surface colour (‘greening’) and water-surface temperature, and (2) the subsequent correlation between water and the air overhead in terms of heat exchange and evaporation. The analyses will be based mainly on data from Switzerland and northern Italy, as well as on a review of the literature related to eutrophication in general. The proposed research will be groundbreaking: the results, in addition to contributing to a better understanding of our biosphere, could susbtantially expand policy approaches to tackle climate change.

Future developments

In the future, to complete our vision, we would like to analyse data on sea surface temperatures and eutrophication levels, inferred based on sea and lake colour data from satellite images, superimposed with information on the density of zootechnical and ichthyocultural installations, to analyse the links between food production and greening.

Mapping the effects of the agri-food system, both in terms of plant and animal food production, in relation to eutrophication and linking it to climate change could become, like measuring CO₂, a fundamental parameter for developing a new concept of sustainability.

Significance

If the coupling between greening and weather events is supported, the effects of the agri-food production (through nutrient inputs or eutrophic load) should be considered alongside those of CO₂ and other GHGs, adding a fundamental parameter for developing a new concept of human footprint on climate (e.g., a “eutrophication label”).

Timeline

• 0-4 months: Analysis of selected Swiss and Italian lakes (case studies) to examine the association between surface colour and surface water temperature
• 4-8 months: Simulation of the effects of water temperature on air temperature and evaporation using numerical models
• 8-12 months: Disseminating the findings to different educational levels, fostering public awareness of the complex interconnections between human activities, eutrophication, and climate change
• Future: Developing a model with weighted parameters; expand the research trough research calls, Foundations, Governmental entities, Universities and Enterprises associations.

Team

• Paolo Giorgetti, lecturer researcher at SUPSI; aerospace systems engineer; expert in systems approaches and member of the technical secretary of the AQST (Environmental protection of Lake Varese).
• Camilla Capelli, Hydrobiologist; researcher in the Freshwater Ecology Group of SUPSI; expert in phytoplankton ecology, in particular algal blooms and the environmental factors that favour their proliferation in lake systems; satellite data analyst
• Cristina Carcano, Communication lecturer at SUPSI; member of Startup Garage SUPSI; Communication consultant
• Fabio Lepori, Head of SUPSI's Freshwater Ecology Team. Researcher, lecturer and consultant in lake ecology and stream ecology; expert on lake eutrophication and the effects of climate change, with a focus on Lake Lugano
• Federica Rotta, Hydrobyologist; PhD student in the Freshwater Ecology Group of SUPSI, with expertise in the monitoring of plastic pollution in freshwater ecosystems
• Daniele Strigaro, geo-informatics; researcher in the Geomatic group at SUPSI; expert in developing custom monitoring systems for sensing the environment and in analyzing and managing weather and climatic data.

Carbon dioxide and other greenhouse gases (GHGs) are not the only causes of climate change. We propose to assess the neglected effect of the 'greening' of lakes and oceans due to pollution (i.e. eutrophication) on the earth-atmosphere energy balance. Our main hypothesis is that greening exacerbates warming and weather events. If proven, this effect means that nutrients should be considered alongside GHGs in defyining the human footprint on climate, potentially leading to a paradigm shift in climate policy.