Humanity’s consumption comes at a cost to a wide variety of planetary systems that depend on each other for sustainability. Like dominoes, instability in one leans heavily on others in line, creating a series of boundaries that can cause serious problems if they are crossed.
Previous studies have warned that our appetites have pushed at least some of these limits to a breaking point. But as useful as it is to interpret our global ecology in this way, it fails to take into account the accessibility we have – and often don’t – to necessary resources.
Key components of our planet’s life support systems fail when fairness and justice are considered for every area, not just for a few boundaries, but for at least seven counts out of eight, according to a new report from a large international team of researchers. .
Thanks to us, the Earth’s climate, biosphere, water cycle, atmosphere and nutrient cycle are already dangerously out of control for a large part of the world’s population.
But when fairness is taken into account, some scenarios begin to affect parts of our planet much earlier, setting much tighter boundaries. For example, aerosols endanger the health of millions of people around the world, of “where vulnerable groups are disproportionately affected and pollute less.”
The idea of ’secure planetary boundaries’ was explored in 2009 by some of the same researchers behind this latest analysis, including climate scientist Johan Rockström of the Potsdam Institute for Climate Impact Research.
At the time, Rockström and his colleagues thought only about the “safe” biophysical boundaries that the Earth had crossed. By adding a threshold of equity, this new approach takes into account human access to water, food, energy, health and a clean environment.
Needless to say, it’s far from an improved image. The updated report is rather disturbing, to put it mildly.
“The science clearly shows that we risk destabilizing the entire planet,” Rockström said told the ABC.
And yet the world continues to burn fossil fuels, produce synthetic chemicals, deforest land, extract groundwater, destroy rivers and pollute the environment with fertilizers, plastics, forever chemicals, radioactive waste, heavy metals and antibiotics.
All that needs to change, scientists say, and climate action needs to be a top priority.
To stay within ‘safe’ and ‘just’ limits for everyone, Rockström and his colleagues argue that global warming should be limited to 1°C above pre-industrial levels.
That is well below current climate targets and well below our projected reality of about 1.2 °C global average for 2023. Above 1.5°C or 2.0°C warming, researchers participation “the probability of triggering tipping points increases to high or very high, respectively”.
At this point, the damage to the biosphere and the risk of triggering further climate feedback loops increases significantly. And the most vulnerable, poor and marginalized people will be the first to be put at risk.
At 1.5°C (the current target of the Paris Climate Agreement), an estimated 200 million people could experience extreme temperatures and 500 million people could be exposed to long-term sea level rise.
“This number of injuries vastly exceeds the generally accepted ‘leave no one behind’ principle and undermines most sustainable development goals,” the report’s researchers said. to writereferring to a United Nations mission.
Phosphorus and nitrogen are two other safe limits that stand out in the current report. These nutrients are leached into the environment through agriculture and can cause plant and algal blooms that can harm animals, collapse fisheries or pollute drinking water.
Some scientists earlier this year warned we were moving towards ‘phosphogeddon’ by our misuse of phosphorus, which is used to grow crops but is being depleted worldwide at an alarming rate.
The number of crises people are facing at once is overwhelming. These are included in only the last month a food crisis in the Horn of Africa, heat deaths in India, catastrophic floods in Italy, a deadly cyclone in Burma, huge forest fires in Canada and much more. These are all connected to the consequences of our planetary frontier shift and ignoring them will not make them go away or stop happening.
Hundreds of millions of people are at immediate risk and parts of our planet may never be the same again.
“Nothing less than a just global transformation in everything [Earth’s safe boundaries] is necessary to ensure human well-being,” the report said concludes.
“Everything indicates that this will not be a linear journey; it will require a leap in our understanding of how to advance justice, economics, technology and global cooperation in the service of a secure and just future.”
The study is published in Nature.