Planetary boundaries

Context

As per the recent study, six of 9 planetaryboundaries which arenecessary to maintain Earth’s stability and resilience have been breached because of human activities.

What are Planetary Boundaries?

Planetary boundaries are thresholds within which humanity can survive, develop and thrive for generations to come.
They are divided intonine boundaries, which are created a safe operating limit for survival.

The nine planetary boundaries are;

Stratospheric ozone depletion
Loss of biosphere integrity (biodiversity loss and extinctions)
Chemical pollution and the release of novel entities.
Climate Change
Ocean acidification
Freshwater consumption and the global hydrological cycle
Land system change
Biogeochemical flows (nitrogen and phosphorus),
Ocean acidification,
Atmospheric aerosol pollution,
Release of novel chemicals

The planetary boundaries framework helps scientists to track and communicate how these rising pressures are destabilizing our planet.

About the study:

This is the third iteration of the framework carried out by 29 scientists from eight different countries.
As per the assessment six of 9 planetary boundaries have been exhausted.
It mentioned that the six boundaries include;
- Climate change,
- biosphere integrity (genetic diversity and energy available to ecosystems),
- land system change,
- freshwater change (changes across the entire water cycle over land),
- biogeochemical flows (nutrient cycles), and
- Novel entities (microplastics, endocrine disruptors, and organic pollutants).
The researchers set the planetary boundary for atmospheric carbon dioxide concentration and radiative forcing (represents the size of the energy imbalance in the atmosphere) at 350 parts per million (ppm) and 1 Watts per square meter (Wm−2), respectively.
Currently, this has reached 417 ppm and is 2.91 W m−2.
The planetary boundary of novel entities was calculated to be zero. This means humans have transgressed this limit as well.

It is estimated around one million of the 8 million plant and animal species are threatened with extinction, and over 10 per cent of the genetic diversity of plants and animals may have been wiped out over the last 150 years.