Once again, we find ourselves in unchartered territory as sapiens pushes the planet's viability to sustain life to the brink.
Chemical pollution threatens you and me by damaging the biological and physical processes that keep life around the world alive. A new study found that deadly chemical pollutants (a/k/a novel entities) that humans have unleashed on the earth have passed the safety limit of the planet. The study was published in the scientific journal Environmental Science and Technology.
The study focuses on the "The scientific rationale behind the planetary boundary concept is that Earth's climate stability and ecosystem resilience, seen throughout ∼10 000 years of the Holocene, are the result of dynamic biophysical interactions that can now be radically altered by human activities.."
The concept has nine "delicately interconnected and specific threshold conditions. They are: Climate change, the speed of biodiversity loss (both terrestrial and marine), interrupted cycles of nitrogen and phosphorous, the depletion of ozone in the stratosphere, ocean acidification, the use of freshwater supplies, the unrelenting changes in natural lands diverted to human use, chemical use, and increasing aerosols in the atmosphere.
As of 2021, the first five thresholds have been passed, according to The Guardian.
The cocktail of chemical pollution that pervades the planet now threatens the stability of global ecosystems upon which humanity depends, scientists have said.
Plastics are of particularly high concern, they said, along with 350,000 synthetic chemicals including pesticides, industrial compounds and antibiotics. Plastic pollution is now found from the summit of Mount Everest to the deepest oceans, and some toxic chemicals, such as PCBs, are long-lasting and widespread.
The study concludes that chemical pollution has crossed a “planetary boundary”, the point at which human-made changes to the Earth push it outside the stable environment of the last 10,000 years.
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“There’s evidence that things are pointing in the wrong direction every step of the way,” said Prof Bethanie Carney Almroth at the University of Gothenburg who was part of the team. “For example, the total mass of plastics now exceeds the total mass of all living mammals. That to me is a pretty clear indication that we’ve crossed a boundary. We’re in trouble, but there are things we can do to reverse some of this.”
The Conversation interviewed one of the study authors, Patricia Villarrubia-Gómez.
When did humanity breach this limit?
It is difficult to say specifically when humanity breached the planetary boundary for chemical pollution. Unlike other boundaries, this one deals with thousands of different entities.
We know there has been a 50-fold increase in the production of chemicals since 1950. This is projected to triple again by 2050. Plastic production alone increased 79% between 2000 and 2015.
There are 350,000 synthetic chemicals in production globally, and only a very small fraction of these is assessed for toxicity. We know little about their cumulative effects or how they behave in a mixture. This is important, as we are all exposed to (often) small concentrations of thousands of substances over our entire lives. We are only beginning to understand the large-scale, long-term effects of this exposure.
We judged that the boundary had been transgressed because the rate at which these pollutants are appearing in the environment far exceeds the capacity of governments to assess the risk, let alone control potential problems.
What is very important to us is that this study highlights the global scale and severity of chemical pollution. Not only because of the effects of producing and releasing such huge volumes of these substances into the environment on a daily basis, but also because it puts into perspective the consequences of human activity on a geological scale. These changes, led by humans, will have persistent and cumulative effects long after we have gone and industries have stopped pumping them out.
What are some of the possible consequences of exceeding this planetary boundary?
We have observed the problems and risks associated with chemicals and plastics during their entire life cycle. Currently, this is largely linear: from extraction, to production, to use, to waste and, finally, to release into the environment.
Damage can occur at all of these stages. For example, fossil fuels are extracted by processes that can lay waste to entire habitats. These raw materials then give rise to plastics and pesticides which take lots of energy and generate lots of climate-warming gases during manufacture. They are used to wrap food or are applied to farm fields, and then they end up in the soil or in rivers and, eventually, the ocean.
Their environmental impacts might be easiest to visualise according to their effect on other planetary boundaries. Plastics are tightly connected to the climate – approximately 98% of all plastics are made from fossil fuels and will release CO₂ when burned as garbage. Chemicals and plastics both affect biodiversity by adding additional stress to already beleaguered ecosystems. Some chemicals interfere with animal hormone systems, disrupting growth, metabolism and reproduction in wildlife.
It’s right there above you; just look up (with lyrics)