The Earth has all the appearances of a living being: ecosystems that are organs seeking to maintain themselves (they are intentional), distribution networks (water, atmospheric, solar energy). It is tempting even to make human society its brain, with its multiple connections for transport, information, economy, maintenance.
So why are scientists particularly divided on the subject? Half think Gaia is a reality, the other half think it's only a useful model. When both present their arguments, they switch their opinions in one direction or the other.
No doubt the Gaia hypothesis is currently taking advantage because our weakness in maintenance stimulates our guilt. The motivation to change our habits is boosted by the idea that we are slowly killing a living being.
The line between living and non-living is blurred. This blurring partly explains the discordance of opinion. If we see in life the ability to replicate, the Earth does not reproduce. If we see in life an autopoetic capacity, that is to say to repair and maintain, yes the Earth is alive.
The concept of self-genesis is not monolithic. One such organization is built on top of others. The most interesting concept is the height of the hierarchy thus constituted. Life is considered all the more complex because this height is important.
The quid pros and problems with Gaia finally become clear: Gaia actually impresses by its size and not its complexity. It houses complex living things without being itself a complex life form. It's just gigantic.
Gaia is not complex as if humans were really her neurons. Humans communicate but remain independent brains. However, neurons are not independent in their information coding process. Only one of them does not form the slightest thought without the others.
That's the difference between a simple set of information and integrated information. Gaia is not a complex form of life because the most elaborate organizations it hosts are not integrated. Humans are, in isolation, a higher life because they are integrated, while an ecosystem is indeed a model of the interactions between living beings and not a higher life form.
The scientists' hesitation lies there. Gaia is alive and well, but at a frustrated level that does not correspond to the aspirations of the majority of its defenders. Protecting Gaia means preserving our sources of food and well-being. It's about saving us a future. It is not protecting a being superior to us.