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The first version of this article was produced in 2004/2005, when the interdisciplinary field known as “Earth System Science” was still emerging; it only appeared on Wikipedia in 2009.
At the international scale, establishing programs to define indicators, map, and monitor all systemic risks weighing on the planetary environment is increasingly likely to become a major priority.
It is interesting to observe that, over the years, these risks are gradually being taken into account—especially where long-term societal and economic stakes are monitored (World Forum, UN).
Biodiversity responds to the pressure that the environment exerts on living organisms.
Measuring biodiversity therefore provides an indirect way to measure biological stress.
Given current knowledge and measurement capabilities, it seems difficult to evaluate biodiversity at the scale of entire regions: this can only realistically be done locally. A few methods exist for this:
Biodiversity responds to the environment and to the pressure it exerts. Since, in the context of this study, we are specifically interested in what disrupts biodiversity, it is not necessarily useful to measure it directly; rather, we should focus on the pressures the environment applies.
This can be assessed by identifying sources of biological stress.
Biological stress is expressed through aggressions against the environment; it favors the development of certain species to the detriment of many others. A “stressed” ecosystem will respond with an overall impoverishment in absolute number of species, benefiting a few that will occupy the most impacted—or even vanished—ecological niches.
“abundance”: % of individuals belonging to species i
“biomass”: % of total biomass represented by species i
Listing vulnerabilities is a task that should increasingly concern future generations—especially as they will be confronted more and more with global climate change.
For example, the Environmental Vulnerability Index (EVI) is a measure designed by the South Pacific Applied Geoscience Commission (SOPAC) and the United Nations Environment Programme (UNEP) to characterize the relative severity of various types of environmental problems. EVI results are used to focus on planned solutions to negative environmental pressures, while promoting sustainability.[4]
These vulnerabilities are structured according to a 3-level logic (see the next chapter):
See Environmental Vulnerability Index on Wikipedia.
In all cases, starting from these environmental factors, the goal is to identify measurable indicators and determine the most important factors. These must be measured over sufficiently long durations to be considered “relevant/critical”. For example:
We can classify environmental risks according to their environmental sphere of origin. On U-Sphere, this breakdown was used:
In general, dust or volcanic explosions cause cooling of Earth’s atmosphere, because they reflect part of the Sun’s energy back into space and cool the planet. However, very energetic cosmic rays interact only rarely; when they do, they break molecules in the upper atmosphere—typically CO2. This counteracts the greenhouse effect; furthermore, the broken molecules recombine to form water-vapor clouds that modify the planet’s albedo and can create imbalances.
The Solar System is crossed by objects of various sizes that can represent a major risk for Earth. Until recently, these risks largely escaped any possibility of control; today, space agencies—and NASA in particular—are setting up monitoring programs.
The variability of solar activity—and the limited historical depth of our observations—means this risk is still largely underestimated.
Surface of the Sun
Solar plasma
Interplanetary Magnetic Field EM fields generated by solar plasma (/EUV?)
Essentially an interface for storing aerosols and particles, and transforming them under the effects of temperature and solar radiation.
Here we consider feedbacks linked to the activity of living species in relation to environmental changes and to shifting equilibria.
(These causes are not strictly tied to the hydrosphere alone, but are linked to exogenous human and ecological factors.)
Related markers/variables
It is essential for the biodiversity of species that feed on it, and also to cope with the spatial and temporal variability of environmental constraints. Thus, the quality of a marine ecosystem can be assessed through the quality of its “plankton spectrum” (zooplankton and phytoplankton).
These are markers of past climate and of pollution levels.
Here the goal is to measure systemic footprint through human activities.
The survival of the species and environmental equilibria depends upstream on monitoring the parameters listed above.
The environment acts on humans, and in return humans act on the environment: factors of social evolution must therefore be taken into account.
Likewise, the evolution of scientific and technical means (Technosphere) will shape interactions between humans and their environment, and their ability to modify the environment in which they live.
Here are additional parameters that should be considered:
We draw a parallel here between this kind of monitoring and the monitoring that other intelligent species in the universe might carry out, for the purpose of their survival and/or to understand the ecological systems they may encounter.
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