Sentences with phrase «unusually low level of activity»

Not exact matches

It has attributed less than 7 % of all climate forcing since pre-industrial days to «natural forcing components» (i.e. solar), conceding that its» level of scientific understanding» of» natural forcing components» (i.e. solar) is» low», whereas there are many independent studies, which attribute 50 % of the warming observed over the 20th century to the unusually high level of solar activity (highest in several thousand years).

The many solar studies I cited simply used empirical data going back to pre-industrial cold periods coinciding with periods of low solar activity in order to estimate the impact of the unusually high level of 20th century solar activity (highest in several thousand years).

Data extracted from tree rings and Antarctica ice cores indicate that solar activity has indeed fallen to unusually low levels at least three times during the past one thousand years, each drop corresponding to a long, cold spell of roughly a century in duration.