From Watts Up With That?

Guest Post by Willis Eschenbach (@WEschenbach on X, my personal blog is here)

For the usual unknown reasons that are so common in my life, I got to thinking about sunshine hours.

Several people have noted that the decreased total albedo in the CERES dataset not only provides the additional energy necessary to explain a quarter-century of warming. It also gives changes in the total absorbed solar radiation (ASR, incoming solar radiation minus reflected solar radiation) that match up very nicely with the warming.

Now, a problem with the CERES data is that it only covers the last 25 years. So in place of albedo, I thought I’d look at “sunshine hours” instead. This is the percentage of the daylight hours of a day, week, month, or year during which the sun is shining. It’s not albedo, but it’s related. Some research showed that the longest dataset we have is from Oxford in the UK. Here is that record.

Hmmm, sez I … most interesting. Although this isn’t the same as ASR, it’s most definitely increasing.

Next, I looked at Europe. Copernicus has a dataset showing sunshine hours there. It’s shorter, starting only in 1983. Figure 3 shows the Copernicus data.

So I kept looking. My next dataset was from the US. Before ~ 1900, coverage is sparse, but after 1900, there are over 100 stations that record sunshine hours. So I didn’t try to area- weight them, I just took a straight average.

[UPDATE] An alert reader, JohnC, located a sunshine hours graph for the entire UK here. This is their graph.

Having seen that the percentage of sunshine hours was increasing in all the datasets I could find, and having seen that the CERES absorbed solar radiation was increasing, I turned back to the CERES dataset. Recall that “ASR”, the absorbed solar radiation, is the top-of-atmosphere solar radiation minus the solar reflections from the clouds, aerosols, and the surface. Here’s what’s happening with the ASR, shown along with the theoretical increase in forcing due to CO2.

Now, bear in mind that one of the core arguments of the advocates of the idea that CO2 alone causes the recent global warming is that there is no natural explanation for the warming. Here’s the IPCC making that argument, that if the models are only given natural forcings, they can’t replicate the increase in temperature.

But as the ASR data above shows, the change in albedo provides enough solar power to explain the temperature increase without greenhouse gases.

However, note that this does NOT mean that greenhouse gases have no role in setting the temperature. It only means that they are merely part of the story. As I showed in my recently published peer-reviewed study entitled “Computational implementation and empirical validation of a Constructal climate model“, you need both the albedo and the greenhouse gases to explain the changes in the Earth’s temperature.

Blue springtime skies today, lots of sunshine hours, and plenty of outside maintenance calling me … my best regards to all on this most awesome planet.

w.

As Is My Wont: I ask that when you comment, you quote the exact words you are discussing. It keeps the thread from getting lost in misunderstandings.