In the past, the sun was the main external agent affecting climate change on Earth, together with the effects of volcanic explosions and internal factors such as ocean currents. “If man had never started burning fossil fuels, the sun might have been the only agent regulating the climate until the next glaciation. However, back in the 19th century we started an experiment which we are now beginning to suffer the consequences of”, explained the astrophysicist Manuel Vázquez to SINC.
During his masterly conference at the El Escorial summer courses, the researcher pointed out that the possibility of a relationship existing between the sun and climate on Earth is quite “plausible”, since it is the main source of energy of everything that occurs in the Earth's atmosphere, “but empirical tests need to be found that show that such a correlation exists, and over what timescale”. It is not the same trying to find a connection over billions of years, where changes in the sun's interior have an effect (the scientist commented), as looking for variations over just a few thousand years, “where we think only fluctuations in the magnetic energy of stars can play any type of role”.
Vázquez explained that this type of energy is produced on surface structures of the sun linked to the magnetic field. The most well known are sunspots which have variation cycles of every 11 years and others over a longer timescale. The researcher added, “there is evidence to show that after the last glaciation, over the last 10,000 years and before industrial activity commenced, fluctuations in the sun's magnetic energy regulated most of the Earth's climate variations”.
As examples of this correlation, Vázquez said that there is “certain evidence” of a relatively warm period in the Middle Ages, “around about the 11th century” which coincided with a period of high solar activity; on the other hand, in the second half of the 17th century, there was a decrease in solar activity which coincided with a relatively cold period on Earth, “although it appears the effects of the sun might affect certain areas of the planet more than others”.
In any case, based on statistics “it is necessary to find a mechanism that explains that correlation, which is where the main battlefield of this research lies”, Vázquez acknowledged, because, although over the last 30 years it has been possible to measure the variation in the amount of energy that comes from the sun, with an 11 year cycle differences between maximums and minimums are so small that they would appear to have no direct effect on climate. To explain past variations, scientists believe there must be some type of mechanism that amplifies the solar signal, such as changes in the sun's ultraviolet radiation, in the flow of cosmic rays that reach the Earth or in the average electricity of the Earth's atmosphere.
The IAC astrophysicist explained that the sun's influence in climatic variations over the last few thousand years is clear: “When there is more solar activity, there is more radiation from the sun, and any of the above-mentioned processes will intensify, causing warming”. All these signals are very evident in the upper layers of the atmosphere, as shown by data collected in recent years, “but the major problem is transferring such a clear correlation of solar activity observed in the upper layers of the atmosphere to the lower layers, where we measure climate”.
The role of the sun in the Earth’s climatic variations “is not inconsiderable”, but Vázquez pointed out that over the last 40 years solar activity has not increased, and has in fact remained constant or even diminished, which is why it is difficult to attribute a significant global warming effect to it, “the cause of which needs to be looked for in human activities”.
SINC Team | alfa
558 million-year-old fat reveals earliest known animal
21.09.2018 | Max-Planck-Institut für Biogeochemie
Glacial engineering could limit sea-level rise, if we get our emissions under control
20.09.2018 | European Geosciences Union
The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.
This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.
Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...
Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.
"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...
A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.
Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...
Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.
An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...
21.09.2018 | Event News
03.09.2018 | Event News
27.08.2018 | Event News
21.09.2018 | Physics and Astronomy
21.09.2018 | Life Sciences
21.09.2018 | Event News