The more time passes, the more our planet is in danger. The good old Earth that we have populated for several million years and which is around 4.5 billion years old is on borrowed time, as scientists unfortunately too often remind us. Despite this, there has still been too little progress, so much so that a new limit has just been crossed and will further undermine our ecosystem.
The concept of “planetary boundaries”
By 2050, the earth’s population is expected to approach 10 billion human beings. Let’s say it clearly, our planet will become overpopulated and the resources essential to our well-being will diminish more and more significantly. According to many researchers and scientists, the Earth is already dying and it will soon be too late to reverse the trend. And if you think the only problem is climate change, it’s far from it.
In 2009, a group of 26 international researchers evoked the concept of “planetary limits”, since more or less unanimously accepted among the scientific community. These limits constitute thresholds that humanity must not cross, on a global scale, in order to avoid too sudden changes in our environment and thus help ensure the stability of our ecosystem.
However, one of these limits, the sixth, has just been crossed.
Fresh water “out of the safe zone”
If the different values of quantities emitted or extracted from the environment have been refined over time for each limit, however, these have remained the same and are nine in number: climate change (the best known), the integrity of the biosphere, the disruption of the biochemical cycles of nitrogen and phosphorus, changes in land use, the introduction of new entities into the environment (crossed earlier this year), the decrease in the stratospheric ozone layer, the acidification of the oceans, the concentration of atmospheric aerosols and, finally, the use of fresh water.
Until then, it was believed that “only” the first five limits had been crossed. However, the last of them would have been exceeded in its turn lately, according to a study published in the journal Nature. Data on freshwater use (overall consumption of surface water and groundwater per year) indicate that it is now “outside the safe zone”. This includes precipitation, soil moisture, or evaporation.
Green water in danger
But it is more particularly green water, that resulting from atmospheric precipitation and absorbed by plants, which is concerned. The scientists behind the study believe that this type of fresh water has not been properly taken into account until now, although it is essential for life on Earth: “The Amazon rainforest depends on soil moisture for its survival. But there is evidence that parts of the Amazon are drying out. The forest is losing soil moisture due to climate change and deforestation,” can we read in particular Nature.
Suffice to say that this is therefore very bad news for our planet and that, as one might expect, we are the first responsible, since we would have pushed “green water far beyond the variability the Earth has experienced for many thousands of years”. It is therefore our entire ecosystem that could be disrupted in the coming years, and more.
