Up to our eyeballs in 💩💩💩 - Julian Cribb

AUTHOR Julian Cribb AM is an Australian science writer and author of seven books on the human existential emergency. His latest book is How to Fix a Broken Planet (Cambridge University Press, 2023)

Every day humans produce more than a megatonne of excrement and then distribute half of it around the Earth without treatment. We are literally poop-bombing the planet, and every human we add contributes to the pile-on.

Little wonder that our rivers, lakes, harbours and marine parks are becoming dangerously unusable, undrinkable, unswimmable and infested with blooms of toxic algae, disease-causing bacteria, parasites and other noxious lifeforms. We are up to our eyes in the brown stuff.

The average person is said to produce 128g of faeces a day, so 8 people produce a kilo, and 8 billion produce a billion kilos of ordure, a million tonnes a day, or 365 megatonnes every year. The rich, of course, produce a lot more poop than do the poor, as the average rich person swallows 35,000 more meals over their lifetime than does a poor person, besides having larger serves. This tends to emerge in the World Obesity Index.

Treated, partly-treated or untreated, most of our sewage or its nutrient-rich effluent, ends up in the local river, creek or groundwater, and thence flows into the nearest ocean according to a survey by the universities of Utrecht and the United Nations.

Broadly speaking, this is what we do with poo:

• High-income countries: ~74% of wastewater is treated
• Upper-middle-income countries: ~43% treated
• Lower-middle-income countries: ~26% treated
• Low-income countries: ~4.3% treated,

which, geographically, looks like this: 

Figure 1. World wastewater treatment rates.
Source: UNU

However, what looks superficially like an unsavoury local water issue is rapidly emerging into something much bigger – a major planetary pollution threat. The poop-bombing of the Earth.

The world’s rivers are in crisis. The International Rivers website and Global Rivers Report list the following rivers as having the poorest water quality on the planet, the pollution usually including raw sewage as well as industrial waste:

Mekong (SE Asia), Citarum (Indonesia), Ganges (India), Yamuna (India), Buriganga (Bangladesh), Marilao (Philiipines), Sarno (Italy), Yellow (China), Tiete (Brazil), Jordan (West Asia), Columbia (USA), Dvina (Europe), Neva (Russia), Amu-Darya (Central Asia), Tocantins (Brazil) Mississippi (USA), Orinoco (South America), Sao Francisco (Brazil), Wisla (Poland).

Figure 2. World’s most polluted rivers and their catchments.
Source: State of the World’ s Rivers 2026

The 2025 Rivers report notes that, even in countries where sewage is treated “In many cities, raw sewage flows directly into rivers due to old, leaky, or nonexistent treatment systems.“ This is increasing global contamination levels.

“Cities like Delhi (22m), Dhaka (10m), and Manila (13m) treat less than 30% of their wastewater. Combined with stormwater, this floods rivers with pathogens, pharmaceuticals, and microplastics. For example, the Yamuna River in India receives more than 800 million litres of untreated sewage per day from Delhi alone.”

The result is a rise in cases of cholera, typhoid, hepatitis, eye and skin diseases. Over 100,000 deaths a year are attributed to polluted water in the Ganges and Yamuna rivers alone.

One area that is becoming heavily polluted, according to a team of Australian scientists, are coastal marine parks, the cornerstone of global ocean conservation. Coral reefs, seagrass beds, mangroves and other vital fish nurseries are being overloaded with nutrients from human sewage and wastewater, they say.

Studying water quality in 1,855 marine parks worldwide, the researchers found that the parks were consistently more polluted than unprotected areas of sea, pointing to careless human waste management. Around 55% of the world’s coral reefs and 88% of its seagrass ecosystems are exposed to wastewater pollution, they said.

The main pollutant is nitrogen, which acts as a fertiliser in freshwater and marine ecosystems, promoting the growth of algal blooms and seaweeds which smother the corals. Climate change has accelerated problem, providing the warmer conditions and stratification of the water column that, with added nutrients, cause algae to explode.

Fuelled by human waste and fertiliser runoff, toxic algae are taking over lakes, rivers, reservoirs and coastal zones around the Planet, such as the Great Lakes of North America, and picturesque Lake Windermere in Britain. In a worst case scenario, this process could return the Earth to its state two billion years ago when algae ruled the planet and conditions were unfit for higher life-forms.

Britain is a shocking example of the sewage dilemma, where the privatisation of public water authorities led to reckless profiteering by the private corporations that now run it, and a massive increase in the discharge of human waste into its rivers, 84% of which are now in poor health.

It is not just nutrients, either. The discharge of human waste includes steroid oestrogens – female sex hormones – which have been shown to cause male fish to change sex, While it is not the only cause, the clumsy management of human waste is now a primary suspect in the feminisation of human males worldwide. The effects may include crashing sperm counts, growth of male breasts, increased risk of breast cancer in men, changes in sexual preference and loss of male secondary sexual characteristics.

The average human produces 4.5 kg of nitrogen (N), more than a half kg of phosphorous (P), and 1.2 kg of potassium (K) a year in their waste (urine and faeces). This is an invaluable resource that is hardly used globally today, except as an environmental pollutant.

The world fertiliser industry produces around 100 million tonnes of raw N per year, worth over $40 billion, without which a human population of 8.3 billion could not possibly be sustained. Fertilisers are the primary reason that humans have overpopulated the Earth.

However, we also produce 37 million tonnes of raw N in our waste, which is mostly thrown away into the environment where it causes untold harm. If converted to fertiliser this would be worth around $15 billion, and feed nearly three billion people. Unfortunately, this colossal waste is increasing, not decreasing.

Figure 3. Nutrient flows are among the most serious threats to a habitable Earth.
Source: Stockholm Resilience Institute 2025.

The Stockholm Institute’s Safe Planetary Boundaries (above) show that nitrogen and phosphorus (‘biogeochemical flows’) are among the most dangerous assaults humans are making on a habitable Earth – worse even than climate change or extinctions.

It’s not that humans are adding any extra N and P to the Earth system, but rather we are massively concentrating these pollutants in both space and time, to the point where they are going to start rendering the planet uninhabitable, either by us or other large animals. In this we risk turning our world back onto a place fit only for microbes and algae.

What will be history’s verdict on a civilisation that can invent artificial intelligence – but hasn’t the brains to manage and recycle its own waste?

Nature’s verdict is already plain. It is telling us we cannot survive in the long run if we continue to sh*t in our own nest.

Julian Cribb Articles

• Plasticide: a crime against humanity Our Rising Oceans
• Will climate change put women in the ascendant?
• When the water runs out...
• The great dying
• Australia issues ‘terrifying’ climate warning
• 'Died of a delusion': the fate of modern civilisation?
• Collapse is near, scientists warn
• De-icing the Earth: a fatal human choice. 
• Rivers of Death
• Unlike politicians, thermometers do not lie
• Welcome to BunkerWorld: Home of the rich and fearful
•  Wisdom of the elders
•  The black work of Big Oil
•  Stealing the Breath of Life
•  The Earth Uncloaked - a catastrophe in slow motion 
  
•  Military experts warn of climate wars
•  Tackling the Earth Emergency
•  A distracted world marches steadily towards catastrophe