From the article, at the very end: "Whether this effect could have provided a significant contribution to the global warming of the Earth during the last century is an open question. The researchers around Sami K. Solanki stress the fact that solar activity has remained on a roughly constant (high) level since about 1980 - apart from the variations due to the 11-year cycle - while the global temperature has experienced a strong further increase during that time. On the other hand, the rather similar trends of solar activity and terrestrial temperature during the last centuries (with the notable exception of the last 20 years) indicates that the relation between the Sun and climate remains a challenge for further research."