Claim: Based on the increase of solar activity during the twentieth century, it should account for between half to two-thirds of all climate change.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: GHG emissions due to anthropogenic (human) activity are the dominant cause of observed global warming (climate change) since the mid-20th century.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: In 2000, Lassen and Thejll updated their 1991 research and concluded that while the solar cycle accounted for about half the temperature rise since 1900, it failed to explain a rise of 0.4 °C since 1980.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Under this scenario, they claimed the Sun might have contributed 50% of the observed global warming since 1900.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: estimated that the residual effects of the prolonged high solar activity during the last 30 years account for between 16% and 36% of warming from 1950 to 1999.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Their reported relationship appeared to account for nearly 80 per cent of measured temperature changes over this period.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Some studies associate solar cycle-driven irradiation increases with part of twentieth century warming.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: The implications of increasing TSI during the global warming of the last two decades of the 20th century are that solar forcing may be a marginally larger factor in climate change than represented in the CMIP5 general circulation climate models.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Given that records of solar activity are accurate, solar activity may have contributed to part of the modern warming that peaked in the 1930s, in addition to the 60-year temperature cycles that result in roughly 0.5 °C of warming during the increasing temperature phase.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: They conclude that because of this, "long-term climate change may appear to track the amplitude of the solar activity cycles," but that "Solar radiative forcing of climate is reduced by a factor of 5 when the background component is omitted from historical reconstructions of total solar irradiance ...This suggests that general circulation model (GCM) simulations of twentieth century warming may overestimate the role of solar irradiance variability.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Three mechanisms are proposed by which solar activity affects climate:

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Climate models have been used to examine the role of the Sun in recent climate change.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: A study in 2004 concluded that solar activity affects the climate - based on sunspot activity, yet plays only a small role in the current global warming.<ref name="www.mpg.de/english/"></ref>

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Most of the global warming since the mid-20th century is very likely due to human activities.