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Visualizing the Biomass of All the World’s Mammals



Infographic breakdown of the biomass of mammals on Earth

Visualizing the Biomass of All the World’s Mammals

Even as we understand more about the world we live in, certain aspects of it remain undefined or hard to comprehend.

One such example is in the scale and distribution of Earth’s life. What’s the ratio of wild to domesticated animals? How much do all of the world’s humans weigh?

Until recently, such questions were nearly unanswerable. A new report titled The Global Biomass of Wild Mammals helps shed more light on the composition and scale of life on our planet. The research provides an estimate of the biomass of all mammals, globally—including humans.

So, What is Biomass Anyway?

Biomass is simply the weight of living things.

In this study, researchers

created rough estimates for four major categories of mammals: humans, domesticated animals, and those that were found in wild terrestrial and marine environments. A further breakdown of mammal groups are found within each category.

To achieve this, they took the estimated number of species from census data and multiplied it with each species’ average body mass.

One component worth pointing out is that animals contribute very different amounts to the world’s biomass total. For example, whales significantly outweigh rodents in terms of biomass, even though there are fewer species and populations of whales. The fact that whales are so much larger than rodents means that even smaller populations can contribute a meaningful portion to overall biomass.

Mammalian Biomass, Organized Neatly

Each larger cube above represents 20 million metric tons of carbon, and the entirety of the visualization represents all living mammalian life on Earth.

The paper separates mammals into four distinct categories:

CategoryTotal Mass (Mt)Top Sub-Category
Domesticated Mammals651Cattle (416 Mt)
Wild Marine Mammals40Baleen Whales (23 Mt)
Wild Terrestrial Mammals24Even-Hoofed Mammals (11 Mt)

One of the most obvious takeaways from this data is that humans make up one-third of total mammalian biomass.

Perhaps even more strikingly, the animals we’ve domesticated for food, companionship, and labor make up close to 60% of the total weight of Earth’s mammals. Domesticated dogs and cats alone equal the total weight of all other wild land mammals combined.

The world’s sheep, on their own, weigh as much as all the whales and seals in the ocean. Domesticated buffalo such as the water buffalo, a species commonly found in Asia, combine to have the third largest biomass of all mammals.

Finally, there’s one category of mammal that comes way out on top.

Cattle Planet

The global livestock population has risen along with the human population, and cattle are now the top mammal in the world by weight.

In fact, just the United States’ share of cattle matches the biomass of all wild mammals on Earth.

As the standard of living continues to rise for people around the world, beef consumption has been increasing in many developing countries. Of course, raising cattle is a resource and land intensive operation, and there have been very real impacts on a global scale. For one, cows are a major source of methane emissions. As well, in Brazil, which accounts for around 25% of the world’s cattle population, pasture has directly replaced large swaths of rainforest habitat.

Waning Wildlife

At the very bottom of the visualization, dwarfed by humans and domesticated mammals, lies the vast array of wild mammals that live on planet Earth.

It’s sobering to see that the biomass of North America’s human population alone compares closely with that of all terrestrial wild mammals in the world. This includes plentiful creatures like rats and mice, as well as large mammals like elephants and bears.

Below are the top 10 wild mammalian contributors to biomass in the natural world.

RankContributorTotal Mass (Mt)Individuals (millions)
#1Fin Whales80.1
#2Sperm Whales70.4
#3Humpback Whales40.1
#4TAntarctic Minke Whales30.5
#4TBlue Whales30.05
#6White-Tailed Deer2.745
#7Crabeater Seals2.010
#8Wild Boar1.930
#9TAfrican Elephants1.30.5
#9TBryde's Whales1.30.1

In the ocean, whales and seals are the heavyweight champions. On land, deer, and boar come out on top as they are both heavy and plentiful.

Humans have a complicated relationship with large mammals. We feel a very clear connection to these creatures, and they are often the key figures in conservation efforts. That said, even small populations of humans have wiped out large mammal species in the past.

The news that cattle outweigh wild land animals by a factor of 20:1 is a reminder that human influence is perhaps even more powerful than we think.

The more we’re exposed to nature’s full splendor […] the more we might be tempted to imagine that nature is an endless and inexhaustible resource. In reality, the weight of all remaining wild land mammals is less than 10% of humanity’s combined weight. – Ron Milo, Professor of Systems Biology

Where does this data come from?

Source: The global biomass of wild mammals

Data notes: To come up with the numbers above, scientists estimated the total biomass of wild mammals on Earth by manually collecting population estimates for 392 land mammal species, which make up about 6% of all wild land mammal species, and using machine learning to infer the global populations of the remaining 94%. Their estimate includes 4,805 wild land mammal species out of approximately 6,400 known and extant wild land mammal species, excluding low-abundance species for which data are scarce.

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What Does A Net Zero Hotel Look Like?

With the travel and tourism industry committing to halving carbon emissions by 2030, net zero hotels could be here sooner than you think.



The following content is sponsored by

What Does A Net Zero Hotel Look Like?

At COP26 in Glasgow, the global tourism industry committed to halving emissions by 2030 and reaching net zero by 2050. In addition, a recent survey found that over three-quarters of travelers say they want to travel more sustainably in the coming year. 

And the accommodation sector is listening.

In this infographic for our sponsor,, we look at how hotels might evolve to meet the climate challenge. 

Saving the Climate, One Light Bulb at a Time

The data in this graphic comes from a recent study by EY-Parthenon (commissioned by that identified a number of existing carbon-saving initiatives that accommodations could adopt right now to reduce their carbon footprint. 

While no single initiative can bring a hotel’s emissions to zero, taken together they add up to big savings. Collectively, the entire sector could reduce their emissions by 48 million tonnes CO2-eq, equivalent to removing 10.7 million gas-powered cars from the road for a year.

Here is the full list of 24 carbon-saving initiatives considered in the report.

InitiativePotential GHG Emissions Reduction (tonnes CO2-eq)
Retrofit efficient HVAC system35-130
Install energy efficient appliances8-30
Install double-pane windows7-25
Install sunshading on windows1-25
Install low-flow fixtures4-19
Use energy efficient lighting3-9
Turn off minibars by default4-8
Opt-out of daily towel & linen changes3-7
Install (more) insulation1-7
Reduce laundry temperature2-4
Electrify vehicle fleet3-4
Recycle waste2-3
Install smart lift software1-3
Install key card switch in guest rooms1-2
Install motion sensors in corridors for lighting0.4-2
Install efficient pool pumps0.8-1
Place a pool cover0.7-1
Install dual flush toilets0.3-1
Introduce paperless procedures~0.7
Limit food waste~0.7
Eliminate disposables0.4-0.6
Collect rainwater0.021-0.033
Develop native gardens0.008-0.013
Install smart irrigation system0.06-0.013

Individual Results May Vary

Not every initiative will apply to every operation, and the actual impact will vary according to the size of the hotel and where it is located. A Canadian hotel would use more heating than one located in the sunny Bahamas, for example.

At the same time, the impact will depend on several scalable metrics, such as the number of rooms or windows.

But to give you some idea of the individual impact, a full-service hotel with 100 rooms, a pool, and a garden, based in a tropical climate, could reduce their carbon footprint by 215 tonnes CO2-eq.

Taking Stock

If you’ve stayed at a hotel recently, you may have seen some of these initiatives in action. 

Energy-efficient lighting, for example, is almost an industry standard and has been implemented in over 80% of accommodations. Pool covers on the other hand, have been implemented in under 30%, perhaps due to the lack of awareness of that option. Overall, the global adoption average is 45%.

But even that rate has already earned a climate dividend. With the current level of adoption, the sector has already eliminated 39 million tonnes CO2-eq in emissions. The 48 million tonne figure quoted earlier, would be on top of that.

OK, But How Much Does it Cost?

The tourism industry and hotels in particular were among the worst hit during the COVID-19 pandemic and are still making up lost ground. International arrivals were still down 37% in 2022, and the hotel and resort sector was worth $1.06 trillion in 2022 according to Statista, down from a 2019 peak of $1.52 trillion. 

Add inflation, a cost of living crisis, and rising energy prices and you can see why hotel owners might balk at the upfront costs of $4,750 per room or $243 billion for the entire sector. 

Even so, it’s worth noting that most of these initiatives could recover their initial investment in energy savings within 15 years. In fact, 76% of the abatement potential is associated with a positive business case. And if you factor in the climate change cachet associated with these initiatives, and the draw that a program like’s Travel Sustainable badge or a certification by the Global Sustainability Travel Council creates for travelers, hotels are beginning to see the merits of investing.

The Journey Ahead

Hotels and accommodations account for an estimated 264 million tonnes of CO2-eq in direct and controllable emissions, also known as scope 1 and scope 2 emissions. So even after all these measures are implemented, there will still be 216 million tonnes of CO2-eq left to tackle. 

And with global average temperatures already 1°C above pre-industrial levels, it’ll be a big job for hotels and other accommodations to eliminate their share in time. But they have a plan on how to get there.

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Click this link to read The Road to Net Zero report and learn more about the sector’s pathway to net zero.

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