Week 9: Planetary Boundaries Framework Pt. 4 - Post 2
Planetary Boundaries Framework Pt. 4
Planetary boundary framework outlines in-depth ideas and science behind each of the nine, large scale, Earth systems that have an impact on the current stable state. While seven boundaries are well defined, two are broad enough that scientists do not have a specific quantity set: atmospheric aerosol loading, and novel entities.
Aerosol loading is an important boundary because it interlinks with other boundaries. Aerosols are defined as very, very small liquid droplets or particles that are suspended in the atmosphere. They absorb and reflect light, so they are important in Earth's heat balance and the climate system. Tiny aerosols made of dust and other substances are used as a condensation nucleus points; water condenses on the particles and clouds are formed. Aerosol particles are also used as natural micro-surfaces for chemical reactions in the atmosphere, heavily influencing atmospheric chemistry. An example is the depletion of the ozone that happened due to clouds that formed on stratospheric ozone aerosols in the upper atmosphere. Aerosols are a planetary boundary because of the affect human activities have on both direct and secondary aerosols. Direct, or primary, aerosols are emitted directly in the atmosphere through natural systems like the oceans, volcanoes and dust. Secondary aerosols are formed through chemical processes in the atmosphere. For instance, when vegetation emits an organic compound that reacts in the atmosphere to make small particles. Humans affect aerosols through land use change and combustion processes. Activities like global transportation and the industrial process also change emissions of a large number of precursor gases, which become aerosols in the atmosphere. Unfortunately, the human impact is not as simple an anthropogenic increase in aerosols in the atmosphere, or aerosol loading. In some instances human activities remove or relocate aerosols. There is risk of setting off physical and ecological tipping points when atmospheric chemistry is anthropogenically changed. As Dr. Sarah Cornell states "Aerosols are a vital part of the Earth system, and a dynamic part, and also there is a huge amount of variability in their local and regional patterns." Due to this vast variability there is no single boundary that incorporates all the kinds of aerosols globally. Fortunately, there is a strong case for specific sub-boundaries to be defined for particular aerosol systems to maintain a functioning and stable Earth system.
Novel Entities carry significant value for safekeeping humanity's well being. Novel entities are defined as human engineered fundamentally new entities which have integrated into the Earth system but, have not co-evolved with nature. When looking at the dangers of novel entities scientists are concerned about the chemicals and toxins which have bypassed normal ecological and co-evolutionary processes. Unlike natural elements which have toxic effects like salt or snake venom, that are dissipated in the environment because organisms were able to co-evolve with them, these entities have not evolved with nature so living organisms cannot interact safely with them. A commonly known example is DDT, a synthetic pesticide. The pesticide is used to kill agricultural pests and mosquitos, but it kills many other organisms too. It collects in fatty tissue so it is easily carried through the food chain effecting all trophic levels. It also persists for years in soils and sediments. The creation and use of DDT has fundamentally changed the way certain ecological processes happen. Like DDT, dangerous novel entities all have similar traits: toxicity, persistence, global transportation, systemic effects, and risk of irreversibility. Due to the novelty of the synthetic entities science is still trying to pin down specific boundaries. However, one must always apply the precautionary principle here. "Where there is threat of significant reduction or loss of biological diversity, lack of scientific certainty should not be used as a reason for postponing measures to avoid or minimize the threat". Finding the novel entities boundary will require new interactions between science, policy, business, and society. Everyone is exposed to these new global risks so they must be dealt with collectively.
Planetary boundary framework was theorized to safeguard the Earth's desired Holocene like state. Science has already recognized that the Holocene like state is the only known state that can support the modern world, and is optimal for growing populations. By determining which Earth system processes regulate this state, members of the Stockholm Resilience Center have defined the nine planetary boundaries. For further understanding the nine boundaries are broken up into three categories. There are three core systems with large scale tipping points: climate change, ocean acidification, and stratospheric ozone depletion. Then there are four slow systems that operate within the core boundaries allowing them to remain stable: Land use change, freshwater use, biodiversity loss, and global nitrogen and phosphorous cycles. Lastly, there are two processes which are the most heavily effected by human activity: aerosol loading, and novel entities. By analyzing these nine planetary boundaries one can look at global sustainability from a viewpoint of possibility. Global sustainability is the overall goal, and as Professor Johan Rockstrom states "It is about a safe space, by biophysical terms, but also it is about recognizing equity, fairness, and just distribution of the remaining ecological space on Earth to enable a world of soon nine billion people to develop and prosper." The planetary boundaries are exciting developments that enable global sustainability to be operationalized at the local level, for business, industry and for national policies in order to stay within the safe operating space of the Holocene.
Aerosol loading is an important boundary because it interlinks with other boundaries. Aerosols are defined as very, very small liquid droplets or particles that are suspended in the atmosphere. They absorb and reflect light, so they are important in Earth's heat balance and the climate system. Tiny aerosols made of dust and other substances are used as a condensation nucleus points; water condenses on the particles and clouds are formed. Aerosol particles are also used as natural micro-surfaces for chemical reactions in the atmosphere, heavily influencing atmospheric chemistry. An example is the depletion of the ozone that happened due to clouds that formed on stratospheric ozone aerosols in the upper atmosphere. Aerosols are a planetary boundary because of the affect human activities have on both direct and secondary aerosols. Direct, or primary, aerosols are emitted directly in the atmosphere through natural systems like the oceans, volcanoes and dust. Secondary aerosols are formed through chemical processes in the atmosphere. For instance, when vegetation emits an organic compound that reacts in the atmosphere to make small particles. Humans affect aerosols through land use change and combustion processes. Activities like global transportation and the industrial process also change emissions of a large number of precursor gases, which become aerosols in the atmosphere. Unfortunately, the human impact is not as simple an anthropogenic increase in aerosols in the atmosphere, or aerosol loading. In some instances human activities remove or relocate aerosols. There is risk of setting off physical and ecological tipping points when atmospheric chemistry is anthropogenically changed. As Dr. Sarah Cornell states "Aerosols are a vital part of the Earth system, and a dynamic part, and also there is a huge amount of variability in their local and regional patterns." Due to this vast variability there is no single boundary that incorporates all the kinds of aerosols globally. Fortunately, there is a strong case for specific sub-boundaries to be defined for particular aerosol systems to maintain a functioning and stable Earth system.
Novel Entities carry significant value for safekeeping humanity's well being. Novel entities are defined as human engineered fundamentally new entities which have integrated into the Earth system but, have not co-evolved with nature. When looking at the dangers of novel entities scientists are concerned about the chemicals and toxins which have bypassed normal ecological and co-evolutionary processes. Unlike natural elements which have toxic effects like salt or snake venom, that are dissipated in the environment because organisms were able to co-evolve with them, these entities have not evolved with nature so living organisms cannot interact safely with them. A commonly known example is DDT, a synthetic pesticide. The pesticide is used to kill agricultural pests and mosquitos, but it kills many other organisms too. It collects in fatty tissue so it is easily carried through the food chain effecting all trophic levels. It also persists for years in soils and sediments. The creation and use of DDT has fundamentally changed the way certain ecological processes happen. Like DDT, dangerous novel entities all have similar traits: toxicity, persistence, global transportation, systemic effects, and risk of irreversibility. Due to the novelty of the synthetic entities science is still trying to pin down specific boundaries. However, one must always apply the precautionary principle here. "Where there is threat of significant reduction or loss of biological diversity, lack of scientific certainty should not be used as a reason for postponing measures to avoid or minimize the threat". Finding the novel entities boundary will require new interactions between science, policy, business, and society. Everyone is exposed to these new global risks so they must be dealt with collectively.
Planetary boundary framework was theorized to safeguard the Earth's desired Holocene like state. Science has already recognized that the Holocene like state is the only known state that can support the modern world, and is optimal for growing populations. By determining which Earth system processes regulate this state, members of the Stockholm Resilience Center have defined the nine planetary boundaries. For further understanding the nine boundaries are broken up into three categories. There are three core systems with large scale tipping points: climate change, ocean acidification, and stratospheric ozone depletion. Then there are four slow systems that operate within the core boundaries allowing them to remain stable: Land use change, freshwater use, biodiversity loss, and global nitrogen and phosphorous cycles. Lastly, there are two processes which are the most heavily effected by human activity: aerosol loading, and novel entities. By analyzing these nine planetary boundaries one can look at global sustainability from a viewpoint of possibility. Global sustainability is the overall goal, and as Professor Johan Rockstrom states "It is about a safe space, by biophysical terms, but also it is about recognizing equity, fairness, and just distribution of the remaining ecological space on Earth to enable a world of soon nine billion people to develop and prosper." The planetary boundaries are exciting developments that enable global sustainability to be operationalized at the local level, for business, industry and for national policies in order to stay within the safe operating space of the Holocene.
How can we help people better understand Novel Entities? This was brand new learning for me that really stood out when you presented.
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