Earth's breath breadth

As noted, Simon Donner recommends wider circulation of a figure from Coral Reefs Under Rapid Climate Change and Ocean Acidification to help drive home some key points about changes in the earth system. Another useful figure may be one showing spring and autumn zero-crossing dates from Carbon cycle: Sources, sinks and seasons, a short by John B. Miller published in Nature:
If, as evidence suggests, rising temperatures are decreasing the efficiency of terrestrial carbon uptake in the Northern Hemisphere, then this cycle could be substantially altered. To make a slightly fanciful but still useful metaphor (which I first came across years ago in Tyler Volk's Gaia's Body, but which may well be much older) the "natural breathing" shown in the figure may become shallower and/or more erratic, like a patient in a critical condition.