How Growth In Population And Consumption Drives Planetary Change

How Growth In Population And Consumption Drives Planetary Change Rapid population growth and increased consumption are now seen as the main drivers of environmental changes. from www.shutterstock.com, CC BY-ND

The growth of the human population over the last 70 years has exploded from 2 billion to nearly 8 billion, with a compounding net growth of over 30,000 per day. We all breathe out carbon dioxide with every breath. That equates to about 140 billion CO₂ breaths every minute. Isn’t it logical that atmospheric carbon will continue to increase with the birth rate regardless of what we do about fossil fuel reduction?

This question touches on the core of our impact on planetary change. It highlights the exponential growth in the human population, but also homes in on the potential direct input of carbon dioxide from humans, through respiration.

As I explain in more detail below, our breathing does not contribute to the net accumulation of carbon dioxide in the atmosphere. But population growth, combined with an increase in consumption, is now seen as the main driver of change in the Earth system.

Humans: a moment in geological time

Earth has been around for 4.56 billion years. The earliest evidence for life on Earth comes from fossilised mats of cyanobacteria that are about 3.7 billion years old.

From around 700 million years ago, and certainly from 540 million years ago, life exploded into its present myriad forms, from molluscs to lung fish, reptiles, insects, plants, fishes and mammals – culminating in hominids and finally Homo sapiens. Genetic studies suggest hominids evolved from primates around 6 million years ago, with the oldest hominid fossil dating from 4.4 million years ago in East Africa.

Our species appeared around 200,000 to 300,000 years ago, a blink of an eye in geological terms. From Africa, Homo sapiens migrated through Europe and Asia and spread across the world, at lightning speeds.

Part of the question is about a putative link between human biological functions and climate. Homo sapiens is one of more than 28 million living species today, and some 35 billion species that have ever lived on Earth. There has always been a link between life and Earth’s atmosphere, and perhaps the clearest indicator is oxygen.

Life, carbon and climate

Cyanobacteria were the first organisms to master photosynthesis and began adding oxygen to Earth’s early atmosphere, producing levels of 2% by 1 billion years ago. Today oxygen levels are at 20%.

While people inhale oxygen and exhale carbon dioxide (billions of tonnes each year), this does not represent new carbon in the atmosphere, but rather recycled carbon that had been taken up by the animals and plants we eat. Furthermore, the hard parts of human skeletons are potential carbon stores, if buried sufficiently deep.

There is a constant cycling of carbon between geological, oceanographic and biological processes. Homo sapiens is part of this carbon cycle that plays out at the Earth’s surface. Like all living organisms, we derive the carbon we need from our immediate environment and give it up again through breathing, living and dying.

Carbon is only added to the atmosphere if it is taken out of long-term geological stores such as carbon-rich sediments, oil, natural gas and coal.

Planetary impact of humans

But the remarkable growth in human population is surely the critical issue. Ten thousand years ago, there were 1 million people on Earth. By 1800, there were 1 billion, 3 billion by 1960 and almost 8 billion today.

When these figures are plotted on a graph, the growth line looks almost vertical from the 1800s onwards. Population growth may eventually flatten out, but only at around 10-11 billion.

Alongside the unprecedented population growth of humans has been the loss of many non-human species (10,000 extinctions per million populations per year, or 60% of animal populations since 1970), the rapid loss of wilderness habitat and consequent growth in farmed land, over-fishing (with up to 87% of fisheries fully exploited), and a staggering growth in global car numbers (from zero in the 1920s to 1 billion in 2013 and a projected 2 billion by 2040).

The world production of copper is an instructive proxy for human global impacts. As with many commodity curves, the trend from 1900, and particularly from the 1950s, is exponential. In 1900 around half-a-million tonnes of copper was produced worldwide. Today it is 18 million tonnes per year, with no sign of lowering consumption rates. Copper is the feedstock for much of modern-day and future green technologies.

Most parts of the world now experience material consumption as never before. But serious inequality remains, with over 3 billion living on less than US$5.50 a day, and a tiny percentage who own so much.

Some argue that it is not the numbers of people on Earth that count, but rather the way we consume and share. Whatever the politics and economics, the gross consumption level of billions of humans is, surely, the main cause of planetary change, especially since 1950. Present-day atmospheric levels of carbon dioxide are one of many symptoms of human impact.The Conversation

About The Author

Michael Petterson, Professor of Geology, Auckland University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

books_causes

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook icontwitter iconyoutube iconinstagram iconpintrest iconrss icon

 Get The Latest By Email

Weekly Magazine Daily Inspiration

LATEST VIDEOS

The Great Climate Migration Has Begun
The Great Climate Migration Has Begun
by Super User
The climate crisis is forcing thousands around the world to flee as their homes become increasingly uninhabitable.
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
by Alan N Williams, et al
The latest report from the Intergovernmental Panel on Climate Change (IPCC) states that without a substantial decrease…
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
by Toby Tyrrell
It took evolution 3 or 4 billion years to produce Homo sapiens. If the climate had completely failed just once in that…
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
by Brice Rea
The end of the last ice age, around 12,000 years ago, was characterised by a final cold phase called the Younger Dryas.…
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
by Frank Wesselingh and Matteo Lattuada
Imagine you are on the coast, looking out to sea. In front of you lies 100 metres of barren sand that looks like a…
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
by Richard Ernst
We can learn a lot about climate change from Venus, our sister planet. Venus currently has a surface temperature of…
Five Climate Disbeliefs: A Crash Course In Climate Misinformation
The Five Climate Disbeliefs: A Crash Course In Climate Misinformation
by John Cook
This video is a crash course in climate misinformation, summarizing the key arguments used to cast doubt on the reality…
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
by Julie Brigham-Grette and Steve Petsch
Every year, sea ice cover in the Arctic Ocean shrinks to a low point in mid-September. This year it measures just 1.44…

LATEST ARTICLES

green energy2 3
Four Green Hydrogen Opportunities for the Midwest
by Christian Tae
To avert a climate crisis, the Midwest, like the rest of the country, will need to fully decarbonize its economy by…
ug83qrfw
Major Barrier to Demand Response Needs to End
by John Moore, On Earth
If federal regulators do the right thing, electricity customers across the Midwest may soon be able to earn money while…
trees to plant for climate2
Plant These Trees To Improve City Life
by Mike Williams-Rice
A new study establishes live oaks and American sycamores as champions among 17 “super trees” that will help make cities…
north sea sea bed
Why We Must Understand Seabed Geology To Harness The Winds
by Natasha Barlow, Associate Professor of Quaternary Environmental Change, University of Leeds
For any country blessed with easy access to the shallow and windy North Sea, offshore wind will be key to meeting net…
3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
by Bart Johnson, Professor of Landscape Architecture, University of Oregon
A wildfire burning in hot, dry mountain forest swept through the Gold Rush town of Greenville, California, on Aug. 4,…
China Can Meet Energy and Climate Goals Capping Coal Power
China Can Meet Energy and Climate Goals Capping Coal Power
by Alvin Lin
At the Leader’s Climate Summit in April, Xi Jinping pledged that China will “strictly control coal-fired power…
Blue water surrounded by dead white grass
Map tracks 30 years of extreme snowmelt across US
by Mikayla Mace-Arizona
A new map of extreme snowmelt events over the last 30 years clarifies the processes that drive rapid melting.
A plane drops red fire retardant on to a forest fire as firefighters parked along a road look up into the orange sky
Model predicts 10-year burst of wildfire, then gradual decline
by Hannah Hickey-U. Washington
A look at the long-term future of wildfires predicts an initial roughly decade-long burst of wildfire activity,…

 Get The Latest By Email

Weekly Magazine Daily Inspiration

New Attitudes - New Possibilities

InnerSelf.comClimateImpactNews.com | InnerPower.net
MightyNatural.com | WholisticPolitics.com | InnerSelf Market
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.