Humanity has reached a dubious and potentially terminal milestone -- the last time there was this much carbon dioxide in the atmosphere, dinosaurs were the dominant species and the first humans were still millions of years in the future. March was the 11th straight record-setting month for global temperatures.
In recent years, the 1,400 mile Great Barrier Reef of northeastern Australia has been decimated by warming waters.
The impact of warmer, more acidic oceans on the world's reef formations is particularly dramatic. Great stretches of barrier reef are being bleached white because the warmer water is killing the algae that live inside and nourish the coral.
The spectacle of ghostly white reef formations in oceans where brimming colors and large clusters of sea life used to be should alarm us all.
They represent the death and dying of a major part of the ecosystem.
They are white coral skeletons that can't regenerate as long as the water remains warm and acidic.
By any standard of measurement this is one of the world's greatest environmental catastrophes. As images of the devastated coral reefs enter public consciousness in the coming months and years, all of us have to ask ourselves how much of the natural world we're willing to sacrifice by our refusal to adjust dramatically downward our burning of fossil fuels.