We count on plants to absorb carbon dioxide. This ability is a fundamental component of photosynthesis, one of the pillars on which our global ecosystem stands. A new report from Nature says that as temperatures increase due to global climate change, Northern hemisphere flora may start to lose carbon dioxide faster than they absorb it thanks to longer and warmer autumns. According to ENN's writeup ,
This is because in autumn, plant respiration — the process by which plants produce energy and release carbon dioxide — occurs more than photosynthesis, the process by which plants absorb carbon for growth.
The full article is available on Nature's website , though you'll need a subscription to view it (not to mention an advanced degree to get the most out of the technical details).
This is another example of why climate change is such an urgent problem: its effects are unpredictable and may feed on themselves, meaning that time may run out even quicker than current models predict.