Eight tenths of a degree? Think of the Grandchildren!

Guest Post by Willis Eschenbach

James Hansen and others say that we owe it to our Grandchildren to get this climate question right. Hansen says “Grandchildren” with a capital G when he speaks of them so I will continue the practice. I mean, for PR purposes, Grandchildren with a capital letter outrank even Puppies with a capital letter, and I can roll with that.

In any case Hansen got me to thinking about the world of 2050. Many, likely even most people reading this in 2010 will have Grandchildren in 2050. Heck, I might have some myself. So I started to consider the world we will leave our Grandchildren in 2050.

In a recent post here on WUWT, Thomas Fuller floated a proposal that we adopt a couple of degrees as the expected temperature rise over the century. He says in the comments to his thread that

I think we owe it to the people of the world to give them an idea of how much warming they can expect, so they can plan their buildings, businesses, roads and lives. They matter. They don’t care how much of it is due to CO2 or how much is rebound from a LIA due to forcings we don’t understand. They don’t. They probably shouldn’t.

We have temperature rises that we can almost trust from 1958 that show a trend of about 2 degrees for this century if things go on.

To start with, I don’t think we owe people anything more than the scientific truth as we understand it. And if we don’t understand it, as in the case of what the climate may be like over the rest of this century, we definitely owe it to the people to simply say “We don’t know”. Those three little words, so hard to say … so no, we don’t owe people a number if we don’t have one.

Next, predicting the future by extending a linear “trend” is a bad idea, because it puts a totally false air of accuracy and scientific reliability on something that we haven’t much of a clue about, except we’re very sure it’s not linear … As Mark Twain famously wrote of that kind of extrapolation:

In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oolitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod.

And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three-quarters long, and Cairo and New Orleans will have joined their streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.

So extending linear trends is not a good plan, particularly in our current state of knowledge of the climate. The planet may be warmer in fifty years, or it may be cooler in fifty years, we don’t know.

But let’s set all of those difficulties aside. Here’s Fuller’s proposal graphically, using HadCRUT data. (As an aside, the trend 1958-2010 in the HadCRUT data is actually 1.3° per century, not 2°/century as Fuller states. So his figures are an exaggeration of the historical trend.)

Figure 1. A grapical representation of Thomas Fullers proposal that we decree that expected warming will be 2° over the 21st century. Image Source

However, Fuller’s proposal along with a comment from Michael Tobin got me to thinking. How about that two degrees per century, what if it actually happens? That two degrees has always been the big scare number, the tipping point, the temperature rise that would lead to the dread Thermageddon, the temperature where we fall into planetary immolation. So I got to pondering James Hansen’s statement about the Grandchildren, and also Fullers postulation of a historically unlikely 2°warming this century. Two degrees per century is eight-tenths of a degree by 2050, so my questions were:

What would I do differently if I knew for a fact that my Grandchildren would be eight-tenths of a degree warmer in 2050? Or alternatively, how would I feel if I knew for a fact that I had sentenced my as-yet-unborn Grandchildren in 2050 to live in a world that was eight-tenths of a degree warmer?

And you know, I couldn’t think of one single thing about buildings, or businesses, or roads, or lives, that I’d do differently for eight tenths of a degree by 2050. Not one thing. Even if I knew it was coming, I don’t know what that slight warming will do, so what would I do to get my Grandchildren and Puppies and business and bridges ready for it? How would I know what to do to prepare my buildings and roads and life for eight tenths of a degree of warming?

There might be some adverse outcomes from that eight tenths of a degree of temperature rise threatening my Grandchildren in 2050, but neither I nor anyone else knows what those outcomes might be. We’ll assuredly get an extra flood over here, and one less flood over there, it’s very likely to be drier somewhere and wetter somewhere else, in other words, the climate will do what climate has done since forever — change.

But anyone who says they can predict exactly where the floods and droughts might be in that unknown climate future is blowing smoke. And I don’t know if we could even tell if the average temperature changed by eight-tenths of a degree. Here’s why:

Let’s take a real look at what that means, eight-tenths of a degree. Here is the record for the GHCN climate station nearest to me these days, Santa Rosa, California.

Figure 2. GISS Unadjusted and Adjusted Temperature records, Santa Rosa, CA. Adjusted temperature is shown in transparent red, to show the Unadjusted underneath (blue). Bottom panel shows the amount of the adjustment.

Santa Rosa has pretty good record, mostly complete from 1902 to the present. Now, there are a number of issues with the GISS adjustments to this station. Before adjustment there is a slight cooling, and after adjustment that has become a slight warming. Who knew that the urban heat island might work in reverse? In addition, the adjustment in recent years is very rapid. Seems counterintuitive.

However, none of the details of the adjustment is my issue today. Today, I want to highlight the fact that the adjustment in the Santa Rosa record is about a degree in a century. So the uncertainty in the historical record is at the very least about a degree. And this is a good record.

Now, which one is right, the adjusted or the unajusted temperature? Unfortunately, there’s no way to tell. Why? Because an adjustment of a degree in a century is lost in the noise. We often see winters and summers that are three or four degrees warmer or colder than the preceding year or two. We see warm decades and cool decades. A degree is simply not enough change to notice. The oldest men and women living in Santa Rosa couldn’t tell us whether average temperatures were a degree warmer on average when they were kids than they are now. And our thermometers can’t do any better. We simply don’t know whether the ~ 1°C adjustment to the Santa Rosa record is valid or not.

My point is that the adjustment is almost a full degree. This is slightly larger than the predicted temperature rise in the scary stories about 2050 and the Grandchildren and the Puppies. And since the adjustment of nearly 1°C in Santa Rosa is so small that we can’t determine if the adjustment is correct, why should I be concerned about eight-tenths of a degree in 2050? We can’t even measure temperature to that accuracy in a site with good historical records, and I should worry about that unmeasurable change?? I don’t think so.

So no, I’m sorry. I refuse to be scared, even by Fuller’s exaggeration of a linear extrapolation of a cherry-picked trend. I have no problem if my Grandchildren have to face a world in 2050 that is eight-tenths of a degree warmer than it is now, more power to them. Without alarmist scientists armed with megaphones and performance-enhancing mathematics, how would we even know if it were eight-tenths of a degree warmer in Santa Rosa in 2050? Our scientists can’t decide if there is a 1° change in the Santa Rosa record, and yet we’re supposed to fear a smaller change by 2050? I think not.

And what catastrophes will eight tenths of a degree bring? We see decadal swings in the Santa Rosa record that are much greater than that, and there are no ill effects. Yes, I know there’s hosts of scientists out there telling me that awful things will happen from Thomas Fullers stipulated warming, but here is my question:

First, let’s assume that the AGW folks are correct, and that global warming will lead to global catastrophes of a variety of types, all the biblical plagues plus a host more.  Increasing temperatures is supposed to lead to more extreme weather and terrible outcomes, a perfect storm of hundreds of bad effects in what I have termed “Thermageddon”.

Next, let’s note that the globe has been warming, in fits and starts but generally warming, since the Little Ice Age. Estimates of the amount of the warming are on the order of one and a half to two degrees C.

And finally, note that since 1958 (to use Fuller’s start point) we have had much faster warming for half a century.

So my questions are … where are all of the catastrophes from that couple of degrees of warming since the Little Ice Age, and from the half century fast warming since 1958? I mean, James Hansen would excoriate the Elizabethans because they bequeathed not only their Grandchildren, but their great-great Grandchildren, a warmer world. I don’t know how the Elizabethans slept at night, after wishing a degree or more of warming on their poor innocent Grandchildren. And puppies. But where are the catastrophes from the couple of degrees of slow warming since the 1600s?

Seriously, people keep saying that the problem with the climate is that we can’t do laboratory experiments. But for the past three centuries we have two excellent natural experiments. In the first we saw warming century after century, and yet we didn’t experience Thermageddon. Where are the catastrophes?

Then in the second natural experiment we have the much faster warming Fuller talked about since 1958, as shown in Figure 1. During that time the Pacific atolls have gotten bigger, and Bangladesh has more hectares of land. People are better fed than at any time in history. There has been no increase in extreme weather events. Where are the catastrophes resulting from those two natural experiments in slow and fast warming?

So no, I don’t worry about eight tenths of a degree warming by 2050. I sleep content, knowing that my Grandchildren might actually get to the point where they could measure eight tenths of a degree of warming and have a scientific reason to agree on the size of the adjustments … I figure they’ll be able to do it, they’ll be smarter and richer and more powerful than we are, with undreamed of technologies. Heck, they may find out that it actually did warm by eight-tenths of a degree between now and 2050. And by then they may actually have found out whether or not CO2 is the main planetary temperature control knob. And likely they will have a variety of other energy sources at that time.

But regarding the eight tenths of a degree of warming by 2050, I just don’t see what catastrophes that will cause in the real world for my Grandchildren. It certainly hasn’t caused catastrophes up until now.

But then people say, never mind the Grandchildren, what about the other species? Won’t their ranges change?

I’m at about Latitude 38 North. The global average temperature change as one goes north or south at that latitude is about one degree per hundred miles.

So under the Thomas Fuller 2°C assumption, the average isotherms will move 80 miles north by 2050. Again, this is lost in the noise. These kinds of changes have been happening in the climate since forever. The world generally doesn’t even notice. Eight tenths of a degree is just too small, it is dwarfed by the daily, monthly, annual, and decadal temperature swings.

Oh, people will say, but the warming in this case will be much faster than in the past, that’s where the problem will come in. But those people forget that all life adapts very quickly. It has to because the temperature changes so much and so quickly. When the temperature often changes by three degrees from one year to the next, either up or down, plants and animals must (and can) adapt to that change in a single year. The idea that plants and animals can’t adapt to eight tenths of a degree by 2050 doesn’t make sense, when they can easily adapt to a three degree swing up or down in a single year. And we have seen that in the rapid warming since 1958 that Fuller highlighted, there haven’t been any catastrophes, either among humans, animals, or plants. So the “fast warming causes catastrophes” claim doesn’t work either.

Final Conclusion? I’m sorry to be so contrary, friends, but I just don’t see that even Thomas Fuller’s exaggerated (by historical standards) 2° per century warming will bring any kind of problems or catastrophes. The IPCC’s greatest projected warming is said to occur in the extra-tropics, in the winter, at night.

And at the end of the day, you can call me a callow, unfeeling neo-Elizabethan brute willing to sentence his Grandchildren to a warmer world, but I’m not going to lose sleep over having less frigid December midnights in Helsinki Finland, or over Thomas Fuller’s possible (not guaranteed but only possible) eight tenths of a degree of warming by 2050. Warming has not caused catastrophes in the past, and if future warming does happen, there is no reason to expect catastrophes from that either.

I know mine is a minority view. But to change my mind, you’ll have to show me that warming in the past has caused catastrophes and huge problems. Until then, I’m not going to believe that warming in the future will cause catastrophes and huge problems, especially warming that we can barely measure.