Most people, including too many scientists, who place utter faith in climate models tend to be blissfully unaware of their limitations. They are not, in fact, infallible crystal balls. They are glorified spreadsheets. Like all computer models they are only as good as the assumptions built into them and should never be taken as close analogues of the real world.
One of the worst assumptions of climate models, aside from their inability to model clouds, is that they treat solar output as a constant. In fact, the Sun is a variable star and the amount of energy it emits varies on cycles ranging from months to centuries.
This is kind of a biggie, given that the Sun is the ultimate source of almost all the energy hitting the Earth’s surface. In fact, 99.9 per cent of the energy in the Earth’s climate system comes from the Sun.
Despite this, climate change alarmists insist that the Sun is only a minor driver of climate change on Earth.
The IPCC and NASA are convinced that changes in the Sun have very little effect on climate. They rely on two arguments. The first is that changes in solar activity are very small. We measure them with satellites because they cannot be measured from the surface, and we know that the radiant energy coming from the Sun varies by only 0.1%. The magnitude of the changes is better appreciated when we use the full scale. Many scientists believe that such a small change can only produce small changes in climate.
The second argument is that the evolution of temperature does not coincide with the evolution of solar activity. Since the 1990s, solar activity has decreased while warming has continued.
This is a fallacious argument, because it only underscores what we so-called ‘deniers’ already emphasise: the climate is the result of many factors, not just solar output, and not just atmospheric CO₂. The climate alarmists insist that human-emitted CO₂ is the big culprit. Yet, there have been massive climate upheavals in the past, aeons before humans even lit their first coal fires.
These abrupt climate events of the past have been studied and identified by paleoclimatologists. Of all of them, we will focus on four of the most important ones. The Boreal Oscillation, the 5.2 kiloyear event, the 2.8 kiloyear event, and the Little Ice Age.
The four are separated by multiples of 2,500 years and form a cycle that I have called the Bray cycle because that was the name of the scientist who discovered it in 1968.
What was the Sun doing, during these changes? Tree-ring growth can be correlated to the strength of cosmic rays from the Sun entering Earth’s atmosphere.
When we analyze the radiocarbon curve over the last 11,000 years, we observe large deviations that indicate long periods of low solar activity. These extended periods of low solar activity are called grand solar minima and increase carbon-14 production by 2%. The most common ones last about 75 years, and there have been about twenty in the last 11,000 years. The most recent was the Maunder Minimum in the late 17th century. But there are other types of grand solar minima that are much more severe because they last twice as long, about 150 years. The last of these severe solar minima was the Spörer Minimum, which occurred in the 15th and 16th centuries.
There have been only four such Spörer-type grand minima in the entire Holocene. 2,800 years ago, there was the Homer Minimum, 5,200 years ago the Sumerian Minimum, and 10,300 years ago the Boreal Minimum. We know when they occurred thanks to tree rings.
As readers may have already noted, these solar minima coincide exactly with the four major climatic events listed earlier. During each of the grand solar minima, the Earth experienced a tremendous cooling.
These cooling events had a direct effect on human populations.
Every time there was a severe deterioration in the climate, the human population suffered from diminishing resources. And the largest declines occurred when grand Spörer-type solar minima took place. Other population declines also coincide with other cooling periods, confirming our reconstruction.
This tells us that the worst climate changes in the past have been caused by changes in solar activity. It also tells us that what is bad for humanity is cooling, not warming.
So, the Sun has a strong climate effect and cooling was bad for humans in the past. So, what about the present?
Since low solar activity causes cooling, it stands to reason that high activity must cause warming. Solar activity in the 20th century was very high, in the top 10% of the last 11,000 years […]
There are two pieces of good news. The first is that solar activity cannot rise above the 20th century maximum. It is not like CO₂, which can keep going up. The Sun’s activity can stay high or go down, but it cannot go up, so the warming should not accelerate and should not be dangerous […]
The second piece of good news is that if much of the 20th century warming is due to the Sun, then there is no climate emergency. Believing that all climate change is due to our emissions is one of those errors that sometimes occur in science, like believing that the Earth is the center of the solar system, that interplanetary space is full of ether, or that stomach ulcers are caused by stress, not bacteria.
Science is never settled. A provisional, very new discipline, like climate science, is settled even less than most.
