Climate Change book cover

I've written some unorthodox views about climate change before, including my debate with a T-Rex and my suggestions on how to solve climate change. This sparked some climate change debate on my forum.

Given my interest in climate change, Oxford University Press sent me an advanced copy of Climate Change and the Health of Nations: Famines, Fevers, and the Fate of Populations by the late Anthony McMichael. In 2014, McMichael, an Australian public health researcher, died at the age of 72. His two co-authors helped complete his work, which will be published in 2017.

What's the point of the book?

The point of Climate Change and the Health of Nations is to follow the advice of historian Geoffrey Parker, who encouraged us to take the road less traveled: "We have two ways to anticipate the impact of a future catastrophic climate change . . . Either we 'fast-forward' the tape of history and predict what might happen on the basis of current trends; or we 'rewind the tape' and learn from what happened during global catastrophes in the past. Although many experts have tried the former, few have systematically attempted the latter." 

In short, McMichael does what mutual fund managers always tells us not to do: to use past performance to predict future results.

Here are some of the questions that he answers (among many):

  • Did climate change 23,000 years ago hasten the demise of the Neanderthals?
  • How did the prolonged drying of the Sahara 5,500 years ago affect food yields?
  • Did humans in southern Mesopotamia 4,000 years ago suffer due to climate change?

As you would expect, there's plenty of doom and gloom in this book. McMichael reports that "the rate of heating would be about 30 times faster than when Earth emerged from the most recent ice age, between 17,000 and 12,000 years ago." However, there are snippets of refreshing observations. 

The climate has changed rapidly even when SUVs didn't exist

One of the biggest myths about our present-day climate change is that it's the first time in the history of the planet that the climate has changed as fast as it's changing now. The American Institute of Physics proves that's false.

Even McMichael recognizes this when he admits: "While the drying of the Sahara from around 6,000 years ago occurred in unhurried fashion over several centuries, regional changes in climate in the Dead Sea region in the early millennia of the Holocene led to desertification within decades."

It's moments like this that we know that McMichael doesn't have a one-sided argument. Still, he reports, "The last time the planet's temperature rose by 4 degrees was 56 million years ago, but that change occurred over thousands of years, not over a single century."

He's relatively balanced. At times, he's simply brilliant.

The most important sentences in the book

Perhaps the most important two sentences in McMichael's book is when he writes:

"The world's climate is naturally restless; sometimes it changes dramatically, sometimes subtly. Natural influences on the climate system span many tens of thousands of years to a period of months."

This important observation is rarely mentioned in the climate change debate. Most doomsday prophets act as if the climate has always been stable and that it is only recently that it's begun to change. Others will admit that the climate has changed in the past, but they'll insist that it was always glacially slow; now is the only time it's ever been swift. In just two sentences, McMichael demolishes these myths.

Our ancestors always viewed "their" climate as the norm. Despite all the evidence that proves that Earth's climate is ever-changing. 

One of the fascinating ideas he develops is that "climate change is therefore ingrained in our genes, bones, and many cultural practices." The implications of this idea are profound.

McMichael is humble and he reminds us what a wise Frenchman once said:

To be uncertain is disagreeable; but to be certain is absurd.


Is the current climate change human caused or is that the wrong question?

McMichael explains: "Some geologists and paleo-climatologists argue that the recent rise in world temperature is merely business-as-usual for a climatically ever-restless planet; it is not the work of humans. But this 'either-or' argument is spurious. The relevant question is: what additional change to the climate are humans now superimposing on the ever-present natural background changes?"

No matter how you answer his question, you're faced with this situation: "Currently we appear to be heading for around 500-600 ppm by this century's end--and a global temperature that has not existed for at least the last 20 million years."

 It's great that he shatters myths about climate change, on both sides.

Belief in myths allows the comfort of opinion without the discomfort of thought.

John F. Kennedy

One myth is that our current temperature rise is "unprecedented." But digest this statistic: "During the post-glacial thaw between 18,000 and 11,000 years ago the seas rose by around 125 metres, the height of a 40-storey building."

Similarly: "Around 5 million years ago, when the world's prevailing temperature was about 2 degrees C higher than today, the seas were around 10 metres higher than now."

Negative bias

Unfortunately, McMichael makes the same mistake that most climate writers make: emphasize the negative. For example, when diagraming how climate change impacts health he shows that it "influences it," which is the right word. However, then he says that it leads to "property and job loss; displacement; resource conflicts." This, in turn, leads to health impacts: "injury/death; mental/heat stress, infectious diseases, under-nutrition."

Why must it always be bad news? When the earth warms, won't that create more jobs in Canada and Alaska? Won't the nutrition in Siberia improve as denizens are more likely to have fruits and veggies? 

Scientists use the term climate change because some parts of the earth will get wetter and/or colder. And those areas won't necessarily be moving always in the "wrong" direction. In other words, dry areas might get wetter and hot places may get colder. 

It also declares, "Around 100 million years ago the world of dinosaurs was 8-10 degrees celsius hotter than now; not a place that primates like us could inhabit." Really? The T-Rex I debated would disagree.

McMichael continues with the bad news: "Climate change often acts as a risk multiplier, amplifying existing health problems such as diarrhoeal disease, workplace heat-related disorders, and child stunting." 

Can't climate change also act as a benefit multiplier? For example, when the globe warms, won't those in Greenland and Siberia enjoy better health and fewer frostbite injuries? 

McMichael argues: "Humans do not suffer alone; plants and animals are vulnerable to heat extremes."

True. But humans around the arctic poles will probably end up suffering less overall. Meanwhile, plants and animals that live a meager existence there will flourish too. 

The author loses my respect when he says, "Today's sixth extinction, in which the loss of species and ecosystems is occurring as fast or faster as during those earlier natural extinction events...."

He dares to write this when he just finished talking about the K-T extinction event! Later, he mentioned the Toba super-volcanic eruption 74,000 years ago, which is the largest in the last 2 million years and nearly killed all humans. Both of those events were far faster and graver than what we are experiencing now.

His book focuses on lots of negative events in human history. He has the self-awareness to realize why that is:

"Changes in climate over the past 10,000 year have brought good times and bad times. Human life expectancies have fluctuated, fertility rates likewise. The historical record, however, is asymmetric; adversity receives more detailed treatment."

 In that spirit, one of the annoying aspects of the climate change debate is how most people focus on the negative. I prefer a more balanced approach:

"Every modification of climate, every disturbance of soil, every interference with the existing vegetation of an area, favours some species at the expense of others."

Joseph Hooker


Will malaria make a comeback?

Malaria comes from Italian, mal aria, meaning "bad air." It's a pathogen that's been detected in Egyptian mummies from 5,000 years ago. "Molecular analyses have identified remnants of the malarial plasmodium in the opulently entombed mummy of King Tutankhamen. The boy-pharaoh died in 1324 BCE at age 19, stricken with multiple lower-limb and spinal deformities attributed to his strongly inbred genetic inheritance; his royal-divine parents were apparently brother and sister. With a weakened immune system, his death may have been due to severe cerebral malaria, the lethal calling--card of falciparum malaria."

Will more people die of malaria now that the earth is warming? Certainly, malaria favors tropical zones. If the USA becomes tropical, will malaria return? McMichael doesn't make predictions, but here's the benchmark:

"Each year 200-300 million cases occur, causing 700,000 deaths, including about one-fifth of all child deaths in sub-Saharan Africa. 

There's a silver lining if malaria returns to the Western world. Once it becomes our problem (again), we'll put far more resources to come up with a solution. Other tropical regions will ultimately benefit. McMichael mentions: "One benefit of this drier period in sub-Saharan Africa was the decline of the deadly infectious disease, sleeping sickness."

Homo sapiens genes

As I try to understand Africa and how civilizations evolved there, I've delved into genetics. I was glad to see McMichael discuss this topic too. 

For example, a couple of years ago, we learned that 3-4% of non-African humans have Neanderthal genes. Neanderthals gave homo sapiens red hair, a skin type attuned to the prevailing chilly environment, and an immunity-related gene enabling detection of 'foreign-looking' amino acids, other genes that make some susceptible to liver cirrhosis, Crohn's disease of the bowel, and type II diabetes.

The Denisovans also may have interbred with Homo sapiens, particularly the branch that then spread through Oceania.

Overall, an estimated 3-4 percent of the average individual human genome in populations outside Africa comes from interbreeding with those other two Homo species. In total, it appears that around one-third of all Neanderthal and Denisovan genes were passed on to Sapiens humans.

Today's Tibetans have acquired from the Denisovans a gene variant that enhanced oxygen uptake by red blood cell hemoglobin, facilitating human survival at high altitude. The Sapiens immune system was a particular beneficiary of this interbreeding since both the Neanderthals and Denisovans had been adapting to Eurasian environments and their particular microbes for several hundred thousand years before coming into contact with the newly-arrived Homo sapiens.

Africans never invented the wheel nor an ocean-worthy vessel, which astonishes me. However, they were not alone. As McMichael documents, the Mayans were a "civilization without wheels, metal tools, sails or beasts of burden, living in an environment with rainforest soils of mediocre fertility, few navigable rivers, and limited freshwater supplies."

The elephant in the room isn't an elephant

It's our population growth. Those who want to diminish climate change point to many possible solutions. However, they rarely point to the one that would have the most long-term impact: our population growth.

In 2012, The Royal Society declared, "rapid and widespread changes in the world's human population, coupled with unprecedented levels of consumption, present profound challenges to human health and wellbeing, and the natural environment."

It's one of the rare statements that population growth impacts health and the ecosystem.

Early farming emerged 10,000 years ago, when there were only 5 million humans. Today, with 1,400 times as many people on Earth, total global energy use has gone up 20,000 times. Meanwhile, Niger's population will go from 17 million today to 55 million by 2050; that's the fastest growing country on Earth. 

There is almost no environmental problem that wouldn't be substantially improved if we depopulated. We could all live as lavishly as Donald Trump if there were only 1 million humans. It's an extreme example, but it's true. Even if dropped to 3 billion or 1 billion, so many environmental problems would get fixed. Don't breed, if you want to save the earth.

When your only tool is a hammer...

...everything looks like a nail.

Jared Diamond is an expert geographer. One of the flaws of his book, Guns, Germs, and Steel, is that he uses geography to explain why some regions on earth did better than others. Although he doesn't claim that geography is the only reason, some careless readers may jump to that conclusion since Diamond doesn't remind the reader often enough to avoid blaming geography for everything under the sun.

McMichael makes a similar error in his book. Instead of geography being his main lens, it's climate change. Therefore, he has a tendency to claim many of the world's big events on climate change:

  • The rise of the ancient Egypt? Climate change did that.
  • The Roman Empire? Was graced with a warm period during its boom centuries.
  • Bubonic plague? Climate changed contributed.
  • The Nazi 1942 defeat in the USSR? An unusually cold winter.

And so on. Just like Jared Diamond doesn't explicitly claim that geography is the sole tool that we should consider, McMichael isn't claiming that climate change explains everything. For example, he states, "The decline and then collapse of the Classic Maya civilization was neither a single-cause event nor a synchronised process."

Similarly, he writes that "we will encounter increases in hunger and starvation, infectious disease outbreaks and violent conflict, all due in part to the climatic changes, environmental stresses, and social turbulence...." [my emphasis]

I wish he would caution the lazy reader more often from using one tool to explain all of history. Instead, he fuels that notion by providing a mountain of evidence.

Still, one has to wonder if McMichael's correlations prove causation. At times, it may simply be a coincidence that a change in climate coincided with the rise or fall of a civilization. Or perhaps climate played a minor contributing role to the ultimate outcome and was not the main driver. What about economics? Politics? Philosophy? Morality? 

Despite the book's flaws, the exercise of looking at past climate change to help us plan for future climate change is an excellent idea. 

The bottom line is that correctly predicting the future, especially the future climate, is nearly impossible. That doesn't mean we should throw our hands up in the air and give up, nor does it mean that we should ignore all predictions. It just means that we should remain humble and open-minded when considering climate predictions. And realize that the only real important action that we can take is lowering our population growth rate. All other actions are helpful, but not nearly as powerful.

Moreover, let's remember that the warming of the planet will probably be a good thing overall for humanity, as long as it happens slowly. Canadians, Russians, and Scandinavians will celebrate. McMichael observes: "We accept gradual changes that we would reject if they happened abruptly."

The last paragraph of the book begins with these two astute sentences: 

Yet our species has not been tested collectively, globally, like this before. Human ingenuity and imagination may flourish as never before.

VERDICT: 8 out of 10 stars.

Before you go, watch the last 5 minutes of this video (jump to minute 45). Geologists estimate how the earth will look like 50, 100, and 250 million years in the future when the tectonic plates will have shifted all over the map. The climate implications are biblical. And they will happen whether we primates are here or not. 


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