It is often said that you can't unscramble an egg. An egg has a wholeness or integrity, a poised arrangement of membranes and layers. You cannot reverse the breaking, mixing, and cooking, even with the most advanced technology and equipment.
But a hen can. Feed her a scrambled egg or two, and she can lay a new, whole egg. It may not be instant, but expensive technology is not required. If the egg is fertile, it can become a new hen, who can unscramble more eggs, and so on.
It's important to remember the relationship here, and who has the power. The hen wants to eat it, and produce a new egg, for reasons that are hers, not ours. Like all the biosphere's organisms, she is self-motivated. Trying to force her may cause problems for both her and us. If we want the egg unscrambled, we invite her.
We've got a scrambled egg situation on a global scale: biodiversity loss, extensive land degradation, water shortages, acidifying oceans, and too much heat-trapping carbon in the atmosphere. But we've framed it in such a way that the hen isn't even in the picture.
Of all these large problems, it was perhaps inevitable that carbon in the atmosphere took center stage in the 1970s and after. The data about rising carbon dioxide in the atmosphere were clear. Physical sciences were dominant in climate questions, and the scope and variability of the biological carbon cycle were only beginning to emerge.
That transparent carbon dioxide gas absorbed and emitted long-wave radiation, thus trapping heat, had been discovered in the 1800s. By the 1960s it was clear that atmospheric carbon dioxide was increasing steadily. But it took another generation, as well as a massive and varied accumulation of evidence, before most scientists and the public began to accept the possibility that climate could change as a result of human activities, and that fossil fuel burning was the main driver.