When we talk about anthropogenic changes, those derived from human activity, The first thing that usually comes to mind is the climate. Much has been said about the impending catastrophe that is rising temperatures, and it is even repeated over and over again that the “safe limit” is 1.5°C higher than in the pre-industrial era. This means that if the planet’s temperature exceeds this limit, the consequences can be devastating for life. However, we are not yet past that limit, and we have already started to notice these changes. In other words, many populations have seen their livelihoods affected due to climatic events derived from the rise in temperatures.
So even though we know that safe limit for ecosystems, what is the fair limit? That is, from what moment do human beings experience damage derived from these changes? When do you stop having access to the resources necessary for a dignified life? For the first time, an international team of 40 researchers has defined the concept of “fair limit”, and has modeled, quantified and incorporated into scientific analysis.
And as Professor Johan Rockström, co-chair of the Earth Commission, director of the Potsdam Institute for Climate Impact Research and lead author of the study, comments: the results are worrying.
WELCOME TO THE ANTHROPOCENE
There are three things in life: Health money and love. And while this popular phrase may make sense for human life, it falls far short of what we understand as “life” on our planet. If we leave our world’s orbit for a moment and stop to observe it from the tranquility of space, we will see rain clouds drenching the mainland, coasts battered by waves, columns of smoke from fires that destroy the environment, and a long list of events. that affect the plants, animals and other living beings that inhabit it.
Among these events we will note that not all the changes are of natural origin: there is a bipedal mammal that has influenced practically all the ecosystems on Earth. And it is that humans have been modifying the environment for centuries to adapt it to their needs and, thus, maintain a constantly growing population. The modifications of the human being have created profound imbalances in the different nutrient cycles to such an extent that they could be irreversible. In fact, the changes are so noticeable that The word “Anthropocene” has been around for a long time. to refer to the geological epoch in which we find ourselves in the present.
Entering the Anthropocene is much more nuanced than it might seem. It means that we left the Holocene, which began 12,000 years ago and which is the only time that we know for sure can sustain current ecosystems. But reality shows us that we are getting further and further into unknown territory, especially due to post-industrial age activities. These changes have caused so many imbalances so quickly that they can trigger a reaction that endangers the planet’s ability to support life as we know it.
How to quantify the unquantifiable
Anthropogenic activities do not only affect temperature. They also alter nutrient cycles, such as phosphorus or nitrogen, exploit surface and groundwater, affect biodiversity and cause aerosols. Therefore, for future actions to be effective, it is necessary to quantify and know the limits of all these frontiers.
To put the figures on the table, the following aspects have been taken into account in the study: uuse of fertilizers, access to drinking water, biodiversity, climate and aerosols. The only ones where we are still within safe limits are temperature and aerosols, which are difficult to quantify globally.
What the data says
In fertilizers, the safe limits are situated at a maximum agricultural surplus of 61 million tons per year for nitrogen and between 4.5-9 for phosphorus. Beyond these limits, it is dangerous for the environment due to the eutrophication of the waters. Currently the use of nitrogenous fertilizers exceeds 257 million tons per year and 10 for phosphorus. The just limits are even stricter, so they were outclassed long before.
Regarding drinking water, researchers divide it into river systems and groundwater. The safe limit for river water ecosystems is less than 20% alteration. This limit has been significantly exceeded, since at present more than a third of the channels are altered by dams, drainages or other types of interventions. In groundwater, the limit is that the replacement limit is not exceeded, that is, that more water always enters the system than is extracted. Unfortunately, this is not fulfilled in 47% of the lands that contain groundwater. Again, fair limits are stricter.
Regarding natural spaces, it is estimated that at least between 50 and 60% of the global surface of the planet should be covered by nature and that it was not altered by human activities. Currently this limit has been exceeded, since it is estimated that only 45% of terrestrial ecosystems are natural. In addition, the researchers state that at least 25% of the territory of functional landscapes (such as cities) should be allocated to semi-natural ecosystems, such as parks, which is only true in a third of cases.
Aerosols at global levels are difficult to quantify, but their presence can affect human health and also alter rainfall patterns in the terrestrial hemispheres, so it is necessary to continue with the studies.
And, finally, the temperature has already exceeded the fair limit (which researchers place at 1°C more than in the pre-industrial era) and, located at 1.2°C, we are dangerously close to the safe limit of 1.5°C. The consequences of exceeding these temperatures can lead us to a point of no return. In this scenario, the thawing of the permafrost and the change in ocean currents could cause a domino effect that would release the enormous amounts of greenhouse gases that are trapped by natural barriers, speeding up the process substantially.
Analyzes show that several of the limits have been exceeded both on a global and local scale. This means that they can most likely no longer be avoided. many of the irreversible impacts on the well-being of humanity. Therefore, there is a need to accelerate action to fairly meet existing sustainability goals, including the Paris Climate Agreement, the Kunming-Montreal Global Biodiversity Framework, and the 2030 Sustainable Development Goals.
The measure of the world’s sustainability is evaluated based on the 17 SDGs that the United Nations and its 193 member countries adopted in 2015 to achieve, by 2030, eradicate poverty, fight inequality and injustice and curb the climate change, among other things. There are 17 global challenges that include 169 goals to consolidate a transforming vision of human society.
However, although the message of the article can set off alarm bells due to an environmental cataclysm, it also leaves a message of hope, since it is in everyone’s hands to reverse these trends. Therefore, to complete the three things in life, it would be convenient to add a fourth: health, money, love… and awareness.
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