Separating Anthropogenically‐ and Naturally‐Caused Temperature Trends: A Systematic Approach Based On Climate Memory Analysis.

Separating anthropogenic and natural contributions to global warming is crucial for understanding and predicting climate change, but it is challenging due to the complexity of the climate system. In this study, we try to address this issue by estimating the anthropogenic forcing impacts with its long‐term persistence features properly considered. In this way, a data‐driven approach is proposed to decompose the observed trends from global and regional scales into anthropogenically‐ and naturally‐caused trends. We find that there is a continuous anthropogenic global warming trend since the beginning of the last century, even during the recent global warming hiatus period. On regional scales, the anthropogenically‐forced trends among regions are found at a similar level, while their unevenly distributed warming trends among regions may be attributed to natural causes. Our findings provide new insight into climate warming, and our approach based on persistence analysis provides a new perspective for attribution studies. Plain Language Summary: In the climate system, temperature change is jointly determined by internal natural variabilities, natural forcings, and anthropogenic forcings. Distinguishing their contributions is of great importance and has attracted much attention. While the most widely used attribution tools are typically established on the basis of climate model simulations, considering the simulation uncertainties, data‐driven approaches as complements also play a vital role. The core of data‐driven methods is to separate the contributions of different forcings using statistical methods such as regression analyses. However, one difficulty comes from the climate inter‐scale interactions, which may transmit the influences of forcings to multiscale processes, leading to long‐lasting impacts. In this study, we try to address this issue by properly quantifying the climate memory related components from the considered temperature records, based on which the long‐lasting impacts of anthropogenic forcings may be estimated, and the anthropogenically‐forced & natural trends can be separated. Using this approach, we find the anthropogenically‐forced global warming trend is continuous, even during the recent global warming hiatus period. On regional scales, the anthropogenically‐forced trends seem to be similar among different regions. By properly considering the long‐lasting impacts of anthropogenic forcings, this data‐driven approach provides a new perspective for attribution studies. Key Points: We develop an approach to separate anthropogenically‐ and naturally‐caused temperature trends based on long‐term persistence analysisWe estimate the anthropogenically‐forced global warming trends in different time windows, including the recent global warming hiatus periodThe unevenly distributed warming trends among regions are mainly attributed to natural causes, not anthropogenically‐forced trends [ABSTRACT FROM AUTHOR]

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