Friday, January 17, 2020

Climate Change: A Concise Assessment of What we are Risking.

The text below is a translation of a post that I published in the Italian newspaper "Il Fatto Quotidiano" about two months ago. The idea was to provide a concise statement on the climate situation (no more than 650 words allowed).  I tried to emphasize the risks involved with the "climate tipping points" and criticize the common idea that, since "the Earth's climate has always been changing,"  there follows that "human activities can't affect climate". I can't really say what impact this article may have had -- normally my posts on "Il Fatto" score a few thousand clicks. But, if you have the time to read the comments (78 in total), you may notice that many commenters were not even vaguely touched by my arguments and continued repeating their typical statements, "where is the proof?" "These are just models," "Nobody knows exactly what's the climate sensitivity factor," "The Club of Rome made wrong predictions," etc.  And so it goes....

The failure of the Madrid climate negotiations, the Cop25, was not really unexpected. Even today, very few people, be they politicians or citizens, understand the risks of what's happening, and those who do are accused of "alarmism". But how long can we carry on as if nothing is happening? What do we risk if we do nothing?

The answer is that we risk much more than we can afford. Many studies tell us
this, among others also a recent article published in Nature titled "Climate tipping points — too risky to bet against." Even without going into the details, the title is clear enough to understand that the matter is becoming dramatic. But why so much concern among scientists?

We can summarize the problem in one short sentence: the Earth's climate is unstable. It is something that is emerging with ever greater force from all studies in climate science. Of course, the fact that the climate always changes is a favorite argument of those who deny climate science. Their reasoning is: "the climate has always changed, therefore man has nothing to do with it." Wrong, very wrong: what we learn from past climate changes is instead that the Earth's climate changes easily and, therefore, is not so difficult to change it. And that's where the risk is.

Today the climate seems stable to us because human civilization has developed over a period of about 10,000 years of modest changes in temperature. Some people enjoy speculating about these small variations, for instance discussing how Hannibal's elephants could cross the Alps. Maybe, at the time, it was a bit warmer than today, but they must have had quite some problems with freezing trunks.

But, if we go further back in time, we see that the Earth's climate has seen real, strong, and dramatic changes. In the past, over a span of about a million years, our planet has seen episodes of intense glaciation interspersed with relatively warm periods, such as the one we live in today. In the more distant past, the Earth saw much more radical and catastrophic changes.

To push the Earth from a glacial period to an interglacial one does not take much: small perturbations are enough, the so-called "Milankovitch cycles", related to asymmetries of the movement of the earth around the sun. But what humans are causing with their greenhouse gas emissions and other factors is a much stronger perturbation that drives us to a warmer, much warmer, planet.

What could happen then? There is talk of temperatures
high enough to destabilize the ice caps at the poles and make them disappear. It would not be the first time that the Earth has no ice at the poles, on the contrary, it is a condition that has occurred commonly in the distant past. But, if the biosphere can live even without ice, our civilization has developed with icecaps at the poles, in climatic conditions that have made possible agriculture, trade, maritime transport, and more.

To create enormous damage to us, we don't even need that the icecaps disappear completely. It is enough to lose an important fraction of the ice to change everything: the sea level would rise to submerge existing ports, then we would see acidification and oceanic anoxia, desertification, mass extinctions and a few more effects that would imperil the survival of human civilization difficult, if not actually of our species.

This is the reason for the great concern: it is not so much the fact that the temperature increases, it is that we face the risk of jumping sharply from one climatic state to another without knowing where we will end up. However, we continue to discuss without taking action: few realize that we risk much more than we can afford.


  1. A very good "elevator speech" on the risks. If you'd had more space, maybe you would have added this: Not only the adaptability of our civilization is in jeopardy, but also the adaptability of large portions of the biosphere itself, insects and phytoplancton being two important examples. After all, co2 rise rate during the permian extinction were not higher than today, although it went on much longer than it will this time around. But rate of change, and the strains this puts on evolution's ability to adapt, is an important issue in itself.

  2. permian extinction were not higher than today, although it went on much longer than it will this time around. Ajman Free Zone
    Ajman Media City Free Zone

  3. I'm more concerned about energy depletion compared to climate at the moment, feel more worried about closing the availability of energy compared to the proposal of Cop25: i hoped for a clear action toward pooling around alternative energy sources proposal and implementation compared to the bargain about how polluting country can be.
    Climate and CO2 availability are triggering algae blooming, with issues related, but capturing huge amount of carbon ( ), another interesting evolution is the discovery of a good tech for clear oceanic plastic ( ). Something is still moving, still we have chances but still we need energy!

    1. If your house was threatened 6 times by a bushfire only 500 meters away as mine was in the recent Australian fires you might feel differently.

  4. Climate sensitivity has been grossly underestimated;

  5. Nate and DJ tell us an interesting metaphor to describe "the precautionary principle. The risk of your pants suspenders failing is some slight embarrassment. While if your parachute harness breaks it will be very bad. So we design parachute harnesses with much more strength and caution to err on the side of safety. Right now many people still have an inverted precautionary principle view of Carbon pollution demanding proof that something bad is happening before making any changes.

  6. Nice link to brush up my italian a bit, BTW.

    For me, food - or the lack of - is the most important aspect of climate warming. Houses can be rebuilt, cities can be relocated (at an appalling cost, though), some percent of GDP grwoth can be shrugged but food scarcity (as it is called in UN-speak, some old fashioned people call it still "hunger") is no joke.
    And it might not the great famine of a continent, but the spread of medium sized hunger crisis', inextricably entangled with issues of social dysfunction, bad governance, population growth, wars and desease.
    We are currently seeing an increase in hunger stricken population, after a very long decrease. This is a multicausal effect, but climate warming worsens the boundary conditions of societal and economic development, if not being directly (via droughts and floods) responsable.

  7. Interesting stuffs, and a couple of hard question, to the prof and even to all blog readers.

    1-what do you think about Von der Leyen green new deal for Europe for the next decades?!

    2-Do you think 1000 millions of Euro for the green new deal will save the planet Earth or what else?

    3-Talking about probability, what are che probability in your opinion, all european gas serra reductions will be sterilized by India, south America, USA, China and even Africa gas serra emissions in the next decades?!

    4-Talking about probability, what are che probability in your opinion, all european gas serra reductions will be sterilized by the melting of methane hydrate in Siberia/Alaska in the next decades, turning the climate change megatrends from bad to worse?!

    5-Instead of investing 1000 millions of Euros for the european green deal, do you think CED-DeGasperi (alias USE Army, USE Navy, USE Airforce) should be a much important investiment for european nations rather than the Von der Leyen green new deal?

    Thanks a lots

    1. We have to make a start otherwise no one will do anything. A transition to a green economy can increase wealth and lifestyle through new industries.

    2. Sorry, I don't buy that.

      Europe will waste time and money but the destiny of th world will not turn elsewhere.
      Europe will not build an Continental Defence.
      Europe will not finance via ONU any political of demographic control in Africa.
      The african demographic bomb will raise at 2.4 Billion.
      Overpopulation issue in Africa will tie itself in an insoluble way with climate change damages.
      Punic Wars will detonate in the Mediterranean area on 2050, and Europe won't have any european defence.
      Europe will be surprise by the Punic Wars II.
      Yellow Buffer Zones and Italian and greek penisula will suffer massive armed migrations from Chartago: lethal urban warfighting, climate change damages, epidemic diseases and ethnic genocides, PIL/productiviy collapsing, and massive civil war in italian penisula.
      NATO B61 warheads will stop the caos in the italian and the invasion in the greek penisula, for saving the rest of the Europe area.
      Europe can accept to use italian and greek penisulas as buffer zones for stopping the future regional war from Africa.

      Yellow Buffer Zones (Malta, Crete and greek islands, Cyprus), Italy and Greece nations can't accept to be erased in the XXI century, by urban wars and epidemic diseases & etnic genocides for massive migrations from Africa, italian civil wars and finally B61 nuclear tactics warheads or M51 missiles. That's why, IMHO the CED DeGasperi is more important than Von der Leyen green new deal.

      Talking about climate change and overpopulation, for me it is as talking about the need of CED De Gasperi right now! because for sure in the future Italy will not be able to live on its pubblic debt as Italy did, since 1980. An italian financial collapsing before the explosion of Punic Wars, it will means a small italian nation without the power of doing nothing. An italian exit from Euro, it will mean a super inflation fire and the dissolution of the italian national state, because firms & business always dead in hyper inflation: new middle age will wait for us, if Italy come back to Lira.

      Finally is the time factor: time is running out because the 2020s decade is just started...

  8. Is it permissible to reblog your post in its entirety? The best statement is the second boldface portion.

    Athanasius’ concern over meeting energy demand seems to me typical of a carpe diem attitude toward today’s wants (or to a far lesser degree, needs) and concomitant willingness to sacrifice the future to get them. I judge that much of our collective energy consumption is actually squandering a destructive resource wantonly: too much travel to and fro, ubiquitous lighting 24/7, fashions and fads that create artificially short commodity cycles, heating and cooling of mostly unoccupied indoor spaces, entirely optional entertainments that require massive amounts of money, energy, and effort to goose our senses for roughly two hours, etc. Undoubtedly, global civilization has reliably delivered these things in the past, and many expect to extend these bounties to those few remaining places not yet brought under dominion. However, the costs are racking up and we’re discovering that many weren’t really necessary in the first place. Only 150 years ago, people got along with much, much less. It’s a different world now, and soon will be again.

  9. Wet-bulb temperatures will extinguish the global food supply, long before heat stress kills most mammals (including humans), thus global starvation will occur FIRST as plant production and crops plummet, somewhere between 2050 and 2100 most likely. Human population will massively crash as disease vectors and starvation drastically increase. Civilization as we know it will cease to exist. We are among the very last generation of humans that will remember what it once was. Not long now. ~Survival Acres~



Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)