Semi-arid ecosystems, common across the Australian continent, strongly influence the inter-annual variability and trend in the global terrestrial net carbon sink. Here we explore the future Australian terrestrial carbon cycle using the CMIP6 ensemble, and the dynamic global vegetation model LPJ-GUESS. Uncertainty in Australia's carbon storage in vegetation ranged between 6 and 49 PgC at the end of the century and was strongly linked to biases in the meteorological forcing. Using LPJ-GUESS with bias-corrected meteorological forcing reduced uncertainty in the vegetation carbon storage to between 14 and 20 PgC, with the remaining range linked to model sensitivities to rising atmospheric CO₂ concentration, temperature, and precipitation variability. Reducing this uncertainty will require improved terrestrial biosphere models, but also major improvements in the simulation of regional precipitation by Global Climate Models.

中文翻译：

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解决澳大利亚陆地碳循环对预估气候变化响应的不确定性


半干旱生态系统在澳大利亚大陆很常见，强烈影响全球陆地净碳汇的年际变化和趋势。在这里，我们使用 CMIP6 集合和动态全球植被模型 LPJ-GUESS 探索未来的澳大利亚陆地碳循环。本世纪末，澳大利亚植被碳储量的不确定性在 6 到 49 PgC 之间，并且与气象强迫的偏差密切相关。使用带有偏差校正气象强迫的 LPJ-GUESS 将植被碳储量的不确定性降低到 14 到 20 PgC 之间，其余范围与模型对大气 CO₂ 浓度、温度和降水变化率上升的敏感性有关。减少这种不确定性需要改进陆地生物圈模型，但也需要对全球气候模型对区域降水的模拟进行重大改进。