How solar energy has changed since 1978

Changes in the sun’s energy over the last 45 years

Dr. Peter F. Mayer, tkp.at

According to the official climate narrative, the sun is supposed to have little or no influence on the climate. In fact, however, the sun undergoes considerable changes in cycles of different lengths and has a decisive influence on the Earth’s climate.

The sun affects the climate in various ways. First, through its direct radiation that reaches the Earth. This changes because the sun goes through various activity cycles, which can be recognised, among other things, by the number of sunspots. Second, the distance between the sun and the Earth changes continuously: on the one hand, the sun orbits the centre of mass of the solar system on an epitrochoidal path with a cycle of about 175 years; on the other hand, the Earth’s orbit also changes within the so-called Milanković cycles.

In addition, there are indirect effects: when solar activity decreases, its magnetic field also weakens. As a result, cosmic rays are deflected less strongly and reach the Earth in greater numbers. The particles and atomic nuclei they contain act as condensation nuclei for cloud formation in the upper layers of the atmosphere. The more clouds form, the more sunlight is reflected back into space – and the more the Earth cools.

Moreover, reduced solar activity is often associated with increased volcanic activity. The sulphur and aerosols released also contribute to cooling the climate.

It has been known for centuries that the sun undergoes subtle and less subtle changes over time. When Galileo Galilei pointed his telescope at the sun, for example, he discovered that the sun is not perfect and is often covered with dark spots, the so-called sunspots. Today we know that sunspots are very large structures – often many times larger than the Earth. But it was only in 1978, when the first satellite missions for continuous observation of the sun were launched, that it became possible to measure changes in solar energy directly, without interference from the Earth’s atmosphere.

Instruments for observing the sun on satellites describe the energy reaching the Earth from the sun as total solar irradiance (TSI). These satellite measurements show that the average TSI reaching the Earth is around 1360–1365 watts per square metre (W/m2). They also show that TSI rises and falls slightly over the course of a sunspot cycle (about 8–13 years). However, most satellite missions last only about 1 to 2 sunspot cycles. To study changes in TSI over periods longer than 10 to 15 years, scientists therefore have to combine or “stitch together” the TSI measurements of several satellite missions.

For more than 20 years there has been a scientific controversy between rival teams of scientists about how best to combine the TSI missions into a continuous record for the entire satellite era, i.e. from 1978 to the present.

This is the subject of the study by Ronan Connolly et al. entitled “Multiple New or Updated Satellite Total Solar Irradiance (TSI) Composites (1978–2023)”.

It first examines the methods and results of different researchers. The Active Cavity Radiometer Irradiance Monitoring (ACRIM) team, responsible for NASA’s ACRIM satellite project, for example, chose to use the data of the satellite missions’ science teams. By contrast, the team at the Physikalisch-Meteorologisches Observatorium Davos (PMOD) made various data adjustments to each of the satellite missions before creating its composite.

The ACRIM composite suggested that, in addition to the changes in TSI over a sunspot cycle, there are also long-term changes in TSI between sunspot cycles. It pointed to the possibility that these long-term changes in TSI could contribute to global warming.

The PMOD composite, however, suggested that TSI does not change significantly between sunspot cycles. It ruled out the possibility that changes in TSI are a significant factor in global warming.

The most recent reports of the United Nations Intergovernmental Panel on Climate Change (IPCC) explicitly favoured composites such as PMOD’s over those of ACRIM.

This new, peer-reviewed paper was published in the renowned journal “The Astrophysical Journal”, founded in 1895 and still one of the leading journals for astronomy and astrophysics. This is hard-core physics.

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