From Watts Up With That?

Guest Post by Willis Eschenbach

PART THE FIRST – REAL WORLD

Well, my monkey mind started thinking about the relationship between how much sunshine is absorbed at the surface and the surface temperature. Here’s the CERES satellite data showing the relationship:

Figure 1. Surface temperature and how much solar radiation is absorbed at the surface. Radiation is in watts per square meter (W/m2).

As we’d expect given our daily experience, more sunshine raises the temperature and less sunshine lowers the temperature.

The question naturally arises—just how much does the surface temperature go up for each additional W/m2 of absorbed radiation at the surface?

We can approach this question in three different ways. First, here’s a scatterplot of the monthly values shown in Figure 1, along with the trendline.

Figure 2. Scatterplot, monthly surface temperature versus how much solar radiation is absorbed at the surface. Because there is uncertainty in the monthly averages, I have used Deming regression rather than standard linear regression.

The second way to calculate the relationship between the surface temperature and surface absorbed sunshine is by linear regression on a gridcell basis, weighted by the area of the gridcells. This gives us the same answer, 0.22 °C per each additional W/m2 of absorbed solar radiation.

The third way to examine the relationship looks at the long-term averages of both temperature and absorbed solar radiation as a scatterplot on a gridcell-by-gridcell basis. This allows us to see what is happening at different temperatures.

Figure 3. Scatterplot, gridcell averages, temperature versus average absorbed solar radiation. The slope of the red line shows the trend of temperature with respect to absorbed solar radiation at various temperatures.

There are several interesting things about this graph. First, over most of the earth (central region above), the relationship between absorbed solar and temperature is pretty linear, with an average trend (slope of the red line) being 0.21 °C per W/m2.

To assist in understanding this, here’s a graphic showing how much solar radiation is absorbed at the surface.

Figure 4. Surface absorbed solar radiation (downwelling radiation minus reflected radiation)

You can see the effect of the nearly continuous clouds at the Intertropical Convergence Zone (ITCZ) as a yellow stripe just above the equator.

To return to Figure 3, in the areas where there is little sunlight, the temperature increases very rapidly with increasing sunshine. Here is a map of where those areas are.

Figure 5. Parts of the world where the annual average absorbed solar radiation is less than fifty watts per square meter.

And at the right-hand end of the scale in Figure 3, surprisingly, in areas where average absorbed solar is above about 210 W/m2, increasing the absorbed sunlight doesn’t warm the surface much at all. The average response in the colored areas shown below is 0.03°C per W/m2. Go figure. Here are those locations.

Figure 6. Parts of the world where the annual average absorbed solar radiation is greater than two hundred ten watts per square meter.

The horizontal dotted lines above and below the Equator on the map in Figure 6 show the limits of the tropics. Note that most of the tropical oceans don’t warm much further in response to absorbed solar radiation increasing byond 210 W/m2.

And at the end of that, we have three different estimates of how much temperatures go up when solar goes up and go down when solar goes down. All three of them are on the order of a 0.2 °C temperature change for each 1 W/m2 change in absorbed sunshine. And all three show that temperature varies with absorbed sunshine, going up with more sunshine and down with less sunshine, just as we see every day.

PART THE SECOND – MODELWORLD

After I looked at what is actually happening, I thought I’d take a look at what the models say is happening. The model data is available at the marvelous KNMI website by selecting “Monthly CMIP5 scenario runs. These are from the Fifth Computer Model Intercomparison Project (CMIP5). The surface air temperature is identified as “TAS” (temperature air surface). Downwelling solar at the surface is “RSDS” (radiation shortwave downwelling surface), and reflected surface solar is “RSUS (radiation shortwave upwelling surface). The absorbed radiation is the downwelling solar minus the reflected solar.

I started with the temperature data. I was interested in the historical data, which is essentially identical for the four “Scenarios”, yclept RCP26, RCP45, RCP60, and RCP85. I used the RCP26 data. The historical data ends in 2012. Here’s the CMIP5 mean global historical surface temperature reconstruction compared to the Berkeley Earth global surface temperature.

Figure 7. Berkeley Earth and CMIP5 model temperatures compared.

Well, that’s pretty respectable. The models have done a decent job of emulating the major changes in the historical temperature. (It does bring up the question of how different models with widely differing climate sensitivities can all hindcast the temperature so well, a question I discussed in “Dr. Kiehl’s Paradox” … but I digress.)

Having done all of that, I went to look at the modeled absorbed solar radiation … and my eyes bugged out of my head. Here’s that modeled result. As with temperature, the solar results are basically identical for the four scenarios, so I’m showing RCP26.

Figure 7. CMIP5 RCP26 historical surface absorbed solar radiation anomaly.

YIKES! Temperatures are going up and absorbed sunlight is going down? Say what? How unbelievable is that?

But wait, as they say on TV, there’s more! Here’s the same RCP26 solar data, this time including their projection of absorbed solar at the surface out to the year 2100.

Figure 8. CMIP5 RCP26 historical and projected surface absorbed solar radiation anomaly.

It’s … curious. Modeled surface absorbed solar is decreasing over the historical period all the way right up to 2012, and then it immediately turns around and starts increasing.

Probably just a coincidence.

But consider … if they somehow get rising historical temperatures with falling historical absorbed solar radiation, think of how high their future projections will be with rising absorbed solar radiation. It’s a win-win situation for the alarmists!

And how come I’m the guy who notices these things and not the good folks running the models or the people at CMIP5?

Always new questions.

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Here on the northern California coastal hillside where I live, we are in the midst of an all-too-frequent occurrence … Pacific Gas and Electric, aka PG&E, can’t keep the electricity on. Once again, we’re out of power. Sigh. I just fired up my reliable fossil-fuel-powered Honda i2000 generator, strung the extension cords, and I’m back in business.

But never fear, the geniuses running California have a brilliant solution for the endless outages, brownouts, rolling blackouts, and power shortages.

You ready for their plan? Here it is:

• Increase even further the amount of unreliable, intermittent renewable wind and solar electric generation
• Jack the already outrageous ($0.34/kWh) electrical prices even higher to discourage demand
• Increase the grid load by banning the sale of gas-powered lawnmowers, leaf blowers, garden tractors, chainsaws, etc. by 2024
• Increase the grid load further by banning the sale of gas-powered generators like mine shown above by 2028
• Close the one remaining nuclear power plant, and
• Drive the load on the grid through the roof by forbidding the sale of gas-powered vehicles after 2035 …

Yeah, that’s the ticket. That’ll reduce the brownouts, rolling blackouts, and total outages. Plus it will screw the poor today, but hey, we’re helping the poor in the year 2050 and saving the world, so it’s all for the best in this best of all possible worlds …

Buncha fricken’ rocket surgeons, alright.

My best to all,

w.

You know it but I still gotta say it: When you comment, please quote the exact words you are referring to. This makes everything clear, and avoids the misunderstandings that seem to proliferate on the intarwebs.