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Solar insolation changes, resulting from long-term oscillations of orbital configurations, are an important driver of Holocene climate^,. The forcing is substantial over the past 2,000 years, up to four times as large as the 1.6 W m⁻² net anthropogenic forcing since 1750 (ref. ), but the trend varies considerably over time, space and with season. Using numerous high-latitude proxy records, slow orbital changes have recently been shown to gradually force boreal summer temperature cooling over the common era. Here, we present new evidence based on maximum latewood density data from northern Scandinavia, indicating that this cooling trend was stronger (−0.31 °C per 1,000 years, ±0.03 °C) than previously reported, and demonstrate that this signature is missing in published tree-ring proxy records. The long-term trend now revealed in maximum latewood density data is in line with coupled general circulation …