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The world’s ecosystems are undergoing unprecedented changes due to the impact of climate change 17 and local human activities. A major concern is the possibility of tipping points where ecosystems and 18 landscapes change abruptly to undesirable states. We consider what happens to the timing of tipping 19 points when current stresses strengthen whilst systems experience additional stresses and/or 20 extreme events. We run experiments on four mathematical models that simulate tipping points in 21 lake water quality, the Easter Island community, the Chilika lagoon fishery, and forest dieback. We 22 show that the strongest impacts occur under increasing levels of primary stress, but additional and 23 more extreme stresses in all four models bring the tipping points significantly closer to today. 24 Translating the results to the real world underlines the need for humanity to reduce damaging 25 disturbances and global warming, and to be vigilant for signs that natural systems are degrading more 26 rapidly than previously thought. 27