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Human consumption and production patterns have already exceeded up to five of the nine "planetary limits" or "safe barriers for the proper functioning of the Earth," the conservation director of the World Wide Fund for Nature (WWF Spain) has warned EFE. Enrique Segovia.
Climate change, the rate of extinction of species, changes in land use and biogeochemical fluxes of phosphorus and nitrogen are the subsystems that have already been exceeded, illustrating the increasing risk of human activities on the planet.
Some scientific evaluations point to the possibility that a fifth limit, that of the use of fresh water, has also seen its safety threshold violated.
Segovia acknowledges that "it is not yet clear" what is the range of the safe operating space in this case, although "the Freshwater Living Planet Index shows that between 1970 and 2012 81% of species populations have been lost" that, in addition, they are "the most altered and have suffered a huge impact" during this time, above the land and sea.
Planetary boundaries concept
The concept of planetary limits is "another way of measuring the capacity of nature to absorb the impact of human development", since there are physical and biological characteristics that the Earth has maintained stable for a long time, so if these patterns are distorted "we could enter an uncertain future with irreversible changes for the resources on which we depend."
Despite this, there is scientific uncertainty about the biophysical and social effects of exceeding the limits "and some of them do not yet know how to measure them".
Thus, while the limit of climate change is measured by the concentrations of CO2 in the atmosphere, “there are others such as the loss of ecological functions or that of new products -genetically modified organisms, microplastics or radioactive waste-, whose measurement has not yet been completed. it is clear “, has recognized Segovia.
Biodiversity and climatic conditions, keys
Although all limits are interrelated, this expert points out biodiversity and climatic conditions as "the two factors that maintain stable living conditions on the planet" and those that could withstand "much better" the impact on others.
In other words, a strong ecosystem - with a large number of species - can better resist transgression and deterioration in the other limits.
Some changes in planetary boundaries could be reversed “with drastic measures and enough time”, as has happened with the reduction of the hole in the ozone layer after the Montreal Protocol and the measures to eliminate chlorofluorocarbons (CFCs) from the cooling systems and aerosols.
In other cases, the problem can only be stopped but recovery as such is not possible, as occurs with the extinction of species.
Furthermore, attempts to fix the situation can also be negative because “if, for example, to fight against climate change renewable energies are promoted by installing solar plants or energy crops everywhere, this can also generate important transformations in the use of the I usually".
Responsible food and energy systems
Segovia has insisted on pointing out the food and energy systems as the main responsible for the "excess of the planet's biocapacity" since "a third of the food is wasted and 45% of what is produced in the fields is destined for direct human food “, while 33% is for livestock feed.
For the WWF expert, "we are still not very aware of what is happening ..., only that we are entering an uncertain future in which the human being is the great actor that changes environmental conditions".
Capture of WWF's Living Planet Report 2016, with planetary boundaries. WWF