Let’s Try This One More Time
- Global warming (or climate change or whatever I am supposed to call it) is real.
- Doubling of CO2 concentrations should increase temperatures by 1 degree C absent feedback.
- The “expert” consensus on the ECS is something between 1.5C and 4.5C, but really, it is hard to nail down a precise answer.
- CO2 concentrations have increased by over 120ppm since 1880. Most of this is surely due to human emissions.
- Average global temperatures (ignore the challenges and variation issues) have increased over 0.8C-0.9C over the time period of 1880-today (for fun, compute the implied climate sensitivity here, virtually no one does this simple exercise).
- Half of the temperature increases have come from the 1950s, with half coming before (mass industrialization really picked up after WW2).
- Scientists expect that over half of the late-20th century warming is due to humans. For sake of argument, say ALL of it is. So, the 0.2 to 0.3 of warming at start of period to WW2 happened in a time of much lower industrial activity, the rest in a time of increased human activity.
- Humans continue to emit not only CO2, but also other GHGs, and global CO2 concentrations can be reasonably expected to rise, and quite considerably, over the next century.
- This additional warming will cause sea level rise, ocean acidification, changes in growing patters, insect vectors, water vapor concentrations, more intense storms (though not more frequent), as among the most widely accepted causes.
- These changes will impose real financial and human costs, but not equally so, they will be different in different parts of the world.
- There is tail risk – in both directions, that is really hard to model.
Without going into detail on any of that, I would argue that this is the accepted climate consensus (actually, what is popularly referred to as consensus is much more limited than this, but let’s just go with it).
OK, so what is the reason I am writing all of that? Well, it seems that no matter how many zillions of times you make all of the above clear, you are accused of being a gun-toting, bible-bashing, world-hating Republican who doesn’t even believe the planet is warmer today than in the past. I kid you not. It is quite literally not possible to speak of anything except insane catastrophe and massive original-sinism on this topic.
So, where am I going here? Well, given all of this, I am definitely of the opinion (hopefully folks will grant me the possibility that it is informed via many years of study of both the climate stuff and doing the economics) … that …
- It’s not going to kill you
- It’s just not that big a deal (I can write 100s of pages on this)
- On the other hand, even if the costs of unabated climate change are “not that big a deal” … SO TOO are the costs of well-crafted policies (folks will conveniently ignore that I wrote the latter part).
- If climate change is going to kill us all, it is going to be because we let the far more serious risks that we are used to end up wreaking huge amounts of damage. Just to remind people, the number of suicides in China each year are anywhere from 100,000 to 250,000. The number of young children who die of diarrhea each year exceeds 800,000. The number of people around the globe who die from indoor and outdoor air pollution is 7 million. The number of people around the globe who die from infectious diseases is 10 million. There is not a single climate scenario that gets global annual deaths from climate change (for fun, ask exactly HOW climate change is expected to kill people) anywhere near being relevant in comparison to the latter numbers on this list. The World Health Organization uses a very high estimate that over the next century, climate change will kill an additional 250,000 people per year. My reading of the literature is that nowhere near that number will happen, but just go with it and place it in perspective. This is saying that around the globe, even as billions of people emerge from poverty, and even as the siren call of warning about climate has been sounded year after year after year after year, we are going to having 250,000 people dying in storms, droughts, floods and starvation over and above the baseline levels of suffering. EVEN IF you do not want to challenge any of that, and it is very challenge-able, that number (and enacting policies to reduce it by directly dealing with climate change) is simply not very large when compared to the myriad global risks we already face and also the potential risks that are out there such as global pandemics, biological and nuclear warfare and the like.
- The point is, that climate change is real, can be costly, will not impact people equally … YET, it is just not going to be a “big deal” (yes, go ahead, feel free to interpret that out of context), And no, that doesn’t mean that smart and aggressive policies ought not be followed now – for I believe there are several good no-regrets policies out there. But it is high time for folks to stop telling my kids that they have destroyed mother earth, that this is the gravest threat humanity has ever faced, and that we are doomed. We know how that movie ends.
If I did not have to spend dozens of hours of my life making these points, maybe I’d have a few minutes to actually put the work in to finish the climate economics book – it is sorely needed.