by Eric McLamb
(Updated August 1, 2022)

There are many threats facing life on our planet today.  There always have been since life first began to evolve some 3.8 billion years ago.  This is natural and will not change.   There have been countless extinctions, including the five major mass extinctions which wiped out at least half and as much as 96% of all life on the planet in one event. 

Just think that all life today has evolved from 4% of the species that were alive prior to “The Great Dying” at the end of the Permian period about 252 million years ago.  Naturally, more are likely over the course of Earth’s lifespan.

Fact: Were it not for these extinctions, humans would not exist today.

However, mass extinctions notwithstanding, there are real-time threats that can and will change human life today as we know it.  Although totally lethal, they may possibly spare some human life; but, they can push humanity back to virtual prehistoric conditions.    

To be clear, Earth as a planet is not in danger of obliteration by these threats.  Just ask any scientist.  Earth will continue to live out its projected eight-billion-year life span which is indelibly intertwined with the Sun’s own life cycle. 

In the next roughly five billion years, the Sun will burn up all the rest of its hydrogen and expand to a red dwarf which will totally engulf the inner planets Mercury, Venus, Earth and Mars. 

But life on Earth will be long gone before that happens because the planet is heating up.  It is a natural process.  The habitable life span of Earth is expected to last just about another one billion years from now… if we can avoid deathly catastrophes in the meantime. 

Both man-made and natural threats face humankind every day.  Humans are ultra-resilient and can find a way to deal with most threats we face; but, it is the real life-decimating singularities – many of which are created by humans –  that pose the most imminent threats to life as we know it.The following Top Five Threats Facing Earth and Humanity may surprise you, but they are ranked based on their probability of occurring combined with the level of impact they can or will have if and when they occur.  In every case, it most certainly is not a question or if, but when and how.  Here are Earth’s Top Five Threats Facing and Humanity.

# Five:  Extreme Global Climate Change

Warming Earth NASA

The key word here is extreme.  Climate change is definitely at the top of practically every list of the most important issues facing our planet today.  While this issue primarily focuses on global warming, changes in precipitation, air quality, biodiversity, “habitable” zones and many other areas are part of and affected by climate change.

But let’s face it, Earth has been evolving climatically for 4.5 billion years since its formation.  It certainly has continued to change and evolve since life first appeared over three billion years ago and since the appearance of the first humans a mere 200,000 years ago. 

Human activity has affected global climate change in recent history, but its influence pales in comparison to the global scale of climate change.

However, it is extreme global climate change that would result in epic disruption if not outright decimation of the human species and most life as we know it today. We have already seen the death and destruction wreaked by monster typhoons and hurricanes, unexpected (and expected) volcanic activity, monsoons, extreme heat and extreme cold systems.

So why is it #5 on the list and not at the top?  It is because history has demonstrated for over three billion years that life can adapt and new species can and will evolve, including humans.  Humans are highly adaptable, and they are roaming and nomadic.  The same goes for many lifeforms – fauna and flora — which we have seen migrate as weather conditions and trends change.  There are other earth-threatening phenomena that pose far greater challenges to humanity than global climate change.

According to the United Nations Office for Disaster Risk Reduction, over 600,000 deaths worldwide have been directly attributed to extreme weather over the past 20 years, with another 4.1 billion people “left wounded, displaced or in need of emergency assistance.”  Most of those impacted are in the regions of the United States, Indonesia, China, India and the Philippines.  So virtually no place on Earth is immune from this. 

With Earth’s hottest temperatures normally hovering at 115°F (46.1°C) and reaching as high as 136°F (57.8°C) in the middle east and western portions of the United States and the coldest temperatures averaging around -50°F in Asia where humans live (see Oymyakon, Russia), there is potential for that perfect storm to trigger multiple extreme weather conditions worldwide.  Still humans may survive, but the species could be seriously emaciated and unable to sustain itself.  We cannot change it or prevent it, but we can find ways to survive it. 

# Four:  Pandemic

The Ebola virus, or filovirus, that causes severe hemorrhagic fever in humans and primates, as seen under a microscope. (Image: CDC)

Worldwide, infectious diseases are the leading cause of death in children and adolescents and one of the top three causes of death in adults, according to the World Health Organization (WHO).  One estimate puts the number of identified infectious diseases at 100,000 worldwide.  While there are cures and treatments for most diseases we know of, most deaths occur because such remedies are not available to populations with the greatest needs. 

Most diseases are contained within the regions where they originate, but there have been numerous pandemics – infectious diseases that spread throughout multiple populations and across multiple regions – that have caused global human health concerns.  The most overwhelming – and the most well-known – pandemic the world has known is the Black Plague of 1350, also known as the Black Death

Between 1347 and 1351, the Black Plague originated in Central Asia and spread throughout the rest of Asia and Europe, spreading an untreatable bacterium called Yersinia pestis which affects both humans and animals.

The global influenza outbreak of 1918, also known as The Spanish Flu (it is still not known exactly where this disease originated), infected a third of the global population at that time from 1918 to 1919 with mortality estimated at 50 million people.

The SARS-CoV-2 virus that caused the Covid-19 pandemic. It is only 50-200 nanometers in size. (Image: CDC)

However, the world learned its greatest lesson from the Covid-19 pandemic outbreak from late 2019 to 2022 which infected close to 554.3 million people worldwide, resulting in close to 6.35 million deaths, according to the World Health Organization (WHO). Never in recorded human history has a pandemic literally pushed the global reset button on all human activity everywhere and anywhere while the human race fought to bring it under control.

No nation was spared, no region was missed, and no human was exempted from this pandemic. This submicroscopic (very, very, very, very, very small) virus brought our human society to its knees and created what historians are referring to as the new Era of the Great Adaptation.

Other recent history pandemics before Covid-19 have included smallpox (declared eradicated in 1980 by WHO), HIV/AIDS, tuberculosis and various strains of influenza.  Modern medicine can treat and cure most and at least keep these diseases contained.  Even incurable diseases such as the often-fatal Ebola, polio and even the common cold have treatments.

But it is the really super potent diseases that we have yet to discover – or strains of known diseases that can rapidly spread throughout all populations and can be transmitted by air, water and food –  that would have a devastating impact on humans and all life as we know it. Covid-19 has its variants that could well over-power the vaccines made for its original strains. But there are more virulent threats that could make Covid-19 seem like a mere common cold.

Take superbugs, for instance, strains of bacteria that have become resistant to antibiotics and known effective treatments.  There is also the zika virus for which the Centers for Disease Control (CDC) has declared no vaccine or preventative drug is available to treat it.  All these diseases are easily transmitted throughout human populations and can easily mutate into massive strains and impact significantly large populations of humans. 

Then there are the diseases which are in the evolutionary stage and can emerge at any time for which humans may have no answer.  Humans are already in protect mode with regard to the world’s deadliest diseases, and we attempt to prepare for any eventuality, spending billions of dollars each year on cures, treatments and preventive research.  But, as the saying goes, we are only human.

# Three:  Population

billion people

This issue is usually listed as the number one environmental issue of all.  And for good, solid reasons.  Our human population trends away from sustainability and continues to place strains on systems and resources that people depend on to live healthy lives and survive.

There are nearly 8 billion people currently living on Earth (Source: United Nations DESA), taking up 43% of the planet’s land surface, according to the Center for Sustainability and Global Environment at University of Wisconsin – Madison. 

By 2100, the United Nations Population Division (UNPD) projects the human population could swell to as many as 11.3 billion people.  That is a 52.7 percent increase over today’s numbers and over 1100% since the 1800s.  The world human population reached one billion by 1804 and has increased seven-fold in the 200 years since.  If humans take over all of Earth’s living surface, there will be no room to provide for itself, let alone room for any other living plant or animal populations.

But human population will never reach that point.  If human populations continue to balloon unabated, it will essentially eradicate itself with disease, starvation, harmful and detrimental living conditions and psychological deterioration.  When asked during a lecture series at the University of North Carolina – Wilmington, USA, as to how many people the Earth can sustain, the university’s professor and founding chair of Environmental Studies, Dr. Jack Hall, answered: “That is a very good question.  It depends on how wise we are and how lucky we get.  We really just don’t know.”

With so many people taking so much land that also is needed for biodiversity, agriculture and food production, transportation, healthy living and natural habitats, the question necessarily becomes, “What is going to give?” 

Earth is finite. Earth’s resources are finite. So, populations cannot be infinite; however, the global population continues to grow, taking more and more land, using up more and more resources, demanding more and more energy and housing, and creating more and more humans.  In this way, the human species is its own enemy, perhaps innocently, but an enemy nonetheless.  Zero Population Growth is attainable and is even projected as early as 2150, but we just don’t know. 

# Two:  The Unknown Unknowns

Comet Storm NASA

Pure logic tells us that there is something lurking out there that we have no clue about.  Many things in fact.  We just don’t know.  Why is this number two on the list?  It’s because what we don’t know can and will happen at any moment in time, and it could be so fast and potent that we may well not know what hit us.  Humans are the most intelligent lifeforms on planet Earth (as far as we know).  But we are not that smart nor do we possess the clairvoyance to know all things that could hit us in the blink of eye.

Such unknowns can range from man-induced origins (such as nuclear terrorism or an accidental release of biological Armageddon) to any naturally occurring causes. We just don’t know.  One previous unknown is the debris from the remnants of two giant stars that died in supernova explosions several million years ago not far from Earth that continue to hit the planet today.  While these have no harmful impact that we know of on the planet or its inhabitants, it goes to show anything can be lurking out there.  Just consider the interstellar neighborhood.

Despite the billions of dollars spent on research both within and beyond our planet looking for those unknowns, we will never possess the capability to know them all. But we do know this: there are inestimable powers of the universe and right here on Earth that dwarf humanity’s capabilities to endure.  Inherently, we have no idea what the probability is for this occurring.  But it is real and we would be foolish to think that what we see is what we get.  But we know this as well:  Whatever may happen to humanity, Earth itself will likely continue to live and evolve with diverse life.

# One:  Coronal Mass Ejections


Yes, this can happen to humanity on Earth… it has happened before!  The very source of life for humanity is, indeed, our greatest threat.  Coronal mass ejections (CMEs) are violent ejections of solar gas, plasma and electromagnetic radiation that can propel more than ten billion tons of solar matter outward from the sun’s atmosphere with the power of over a billion hydrogen bombs. 

If Earth were to take a direct hit from a massive CME, it would decimate the global technological society on which the human population depends for survival, from all business activity and communications, to food production and food/water security, medicine, energy and transportation.  It would immediately shut down the infrastructure of our society and plummet living back to before the start of the Industrial Revolution.

Depending on where we are in the 11-year solar cycle of high and low activity, the Sun will discharge one CME per week or as many as two to three CMEs per day.  But most of them miss Earth’s orbit with only about 70 of them hitting Earth each year, most of them small and almost all of those skimming the surface. 

It would take a direct, head-on hit from a very massive CME to fry human society’s technological infrastructure, and we can thank the planet’s magnetic field for providing us at least that level of protection.  The presence of these CMEs and other solar activity can be seen through the Aurora Borealis – or the Northern and Southern Lights – which are created by their interaction with Earth’s magnetic field. 

A direct hit from a very, very large CME is a one-in-100-year event according to solar research at NASA and the European Space Agency.  That makes the probability of a CME-induced threat very high.  Still, in the overall scheme, the chances of a massive CME directly hitting Earth is pretty low, “but still it could happen at any time,” says NASA’s Heliophysics scientist Dr. Jeffrey Newmark. But if and when a CME hits Earth head on, he says, the results would be catastrophic to modern human society.

The Nature of Life and the Universe

While these are indeed real threats to human ecology, they are also simply facts of existence.  There are just some issues we can do nothing about other than to live as responsibly and sustainably as possible.  The latter is where we need to have the most focus… the things we can do something about, but also to be prepared for anything we can think of that would threaten us. 

Population we can control.  Climate change we cannot, but we can impact it both negatively and positively.  Diseases we can only control or manage but so far, as well as prevent what we know bout.  But the unknowns, well, it’s interesting to contemplate them and even figure a few out, but we never will conquer them. 

That is the nature of life and the nature of the universe.  Our concerns are best focused on what we can do and how we can apply our actions to healthy and sustainable living.  Earth will take care of itself and will continue to see the evolution of many new life forms in its very long, yet finite lifetime.  Whatever humanity does as one of millions of Earth’s lifeforms past, present and future, in the final analysis, Earth itself will be fine.  Humanity controls its own destiny as far as it can. EP