14 DAY TRIAL // There is little doubt now about what causes climate change, but whether or not carbon dioxide is the sole factor responsible for global warming is another subject of debate, says Manuel Vazquez of the Canary Islands' Astrophysics Institute. Statistics indicate that the Sun could account for as much as 20 percent of the climate change effects the planet is currently experiencing. In fact, it is widely believed that along with volcanic activity and other factors within the Earth's atmosphere, the Sun was the main agent regulating the climate change on the planet, before industrialization.
"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," said astrophysicist Manuel Vazquez during the Sun and Climate Change conference held by Madrid's Complutense University.
The idea that the Sun is having an influence on the Earth's climate change is not new at all, and has become rather plausible if one considers the fact that the Sun in the only source of energy outside the planet's atmosphere. "But empirical tests need to be found that show that such a correlation exists, and over what timescale," added Vazquez. He also believes that the magnetic energy of the star could play one of the most important roles regarding a possible connection between the clime on Earth and solar activity.
Magnetic energy is produced as the magnetic field fluctuates over the 11-year cycle, producing sunspots. "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," Vazquez said.
Additionally, history has reported more than once the occurrence of relatively warm periods alternated by brief cold periods, which have been linked either to increases in the Sun's activity or to the total lack of sunspots for as long as five decades.
"It appears the effects of the sun might affect certain areas of the planet more than others. It is necessary to find a mechanism that explains that correlation, which is where the main battlefield of this research lies," Vazquez explained. By contrast, measurements conducted over the last 30 years show that the succession of solar maximums and minimums currently has little to no effects on the clime of the planet.
Some scientists believe that some mechanism that could amplify the radiation coming from the Sun and the cosmic rays must also be present, thus measurements have been conducted over the years in the hope that it could be revealed.
"When there is more solar activity, there is more radiation from the sun, and any of the above-mentioned processes will intensify, causing warming." The measurement of these effects is not a problem in the upper atmosphere, "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," said Vazquez.
Although solar activity has actually diminished over the last 40 years, it is rather difficult to discard the role of the Sun in the climate change of the planet as insignificant.