Seven out of nine ‘safe limits’ for life on Earth have been exceeded by humans, scientists warn 

Humans have crossed almost all boundaries that make Earth a safe and just environment, researchers say.

In quantifying the limits of the planet’s life support systems, a team of more than 40 international scientists has found that humans have crossed seven of the eight Earth System Boundaries (ESBs) they identified.

They said social and economic systems based on unsustainable extraction and consumption of resources are causing rapid changes that undermine these systems and push the Earth toward irreversible destabilization.

The scientists published their work in the journal Nature and analyzed climate, biodiversity, fresh water and various types of air, soil and water pollution.

They defined safe and equitable limits as those that regulate the state of the planet, protect other species, reduce significant harm to humans, and support inclusive human development.

Only in the category of aerosol pollutants has this limit not been exceeded, with the climate exceeding the appropriate limit of 1C, but not the safe limit of 1.5C above the pre-industrial average global temperature.

The scientists, who work under the Earth Commission, said “significant societal impacts” are already being felt, with tens of millions of people already affected by the changing climate.

Professor Johan Rockstrom of the Potsdam Institute for Climate Impact Research and lead author of the study said: ‘The results of our health check are quite alarming.

‘Within the five domains analysed, several boundaries are already being crossed, on a global and local scale.

This means that unless a timely transformation takes place, it is very likely that irreversible tipping points and widespread impacts on human well-being will be inevitable.

“Avoiding that scenario is crucial if we are to ensure a safe and just future for current and future generations.”

Since 2015, UN member states have agreed to limit global temperature rise to 1.5°C and to protect biodiversity in 30% of the world’s land, sea and freshwater areas.

The Earth Commission scientists said we are not on track to meet these goals and that “nothing less than a just global transformation of all ESBs is needed to ensure human well-being.”

These transformations must also be systemic, addressing the economic, technological and political drivers of Earth’s degradation and “ensuring access for the poor through reduction and redistribution of resource use,” they said.

Since 2015, UN member states have agreed to limit global temperature rise to 1.5°C and to protect biodiversity in 30% of the world’s land, sea and freshwater areas. The Earth Commission scientists said we are not on track to meet these goals

Co-author Professor Joyeeta Gupta from the University of Amsterdam said: ‘Justice is a necessity for humanity to live within planetary boundaries.

This is a conclusion seen by the entire scientific community in multiple heavyweight environmental assessments.

It’s not a political choice. Overwhelming evidence shows that a just and equitable approach is essential for planetary stability.

“Without justice, we cannot have a biophysically safe planet.”

The researchers said their work is for companies, cities and governments to set science-based targets in addressing human exposure to climate change, biodiversity decline, water shortages, ecosystem damage from fertilizer overuse combined with lack of access elsewhere and health damage from air pollution.

Prof Gupta said: ‘Potential future tipping points are not the only risks we are considering, millions of people are already being harmed by 1C of global warming.

“Our Climate-Earth System boundary exposes the inequity in current targets and underscores the urgency to phase out fossil fuels immediately and accelerate work from all directions to meet the goals of the Paris Agreement.

“By setting our climate-earth system boundary at 1C, we are not advocating for the world to adopt this ambitious target, but are exposing the injustice inherent in current global goals.”