Lovelock and planetary medicine.
Global heating would not have happened but for the rapid
expansion in numbers and wealth of humanity. Had we
heeded Malthus’s warning and kept the human population
to less than one billion we would not now be facing a torrid
future. Whether or not we go for the recommendations for
cutting back fossil fuel use discussed in Bali in 2007 or
use geo-engineering the planet is likely massively and
cruelly to cull us in the same merciless way that we have
eliminated so many species by changing their environment
into one where survival is difficult.

Before we start geo-engineering we have to raise the following question:
are we sufficiently talented to take on what might become the onerous
permanent task of keeping the Earth in homeostasis?
Consider what might happen if we start by using a stratospheric aerosol
[http://www.sciencedaily.com/releases/2008/02/080217094602.htm]
to ameliorate global heating; even if it succeeds it would not be long
before we face the additional problem of ocean acidification.
This would need another medicine and so on. We could find
ourselves enslaved in a Kafka-like world from which there is no escape.

The alternative is the acceptance of a massive natural cull of
humanity and a return to an Earth that freely regulates itself
but in the hot state. Garrett Hardin foresaw consequences of this
kind in his seminal 1968 essay The Tragedy of the Commons
[http://en.wikipedia.org/wiki/Tragedy_of_the_commons].

Whatever we do is likely to lead to death on a scale that
makes all previous wars famines and disasters small.
To continue business as usual will probably kill most of us
during the century. Is there any reason to believe that fully
implementing Bali with sustainable development and the full
use of renewable energy would kill less? We have to consider
seriously that as with nineteenth century medicine the best
option is often kind words and pain killers but otherwise do
nothing and let Nature take its course.

The usual response to such bitter realism is: then there is
no hope for us and we can do nothing to avoid our plight.
This is far from true. We can adapt to climate change and
this will allow us to make the best use of the refuge areas
of the world that escape the worst heat and drought. We
have to marshal our resources soon and if a safe form of
geo-engineering buys us a little time then we must use it.

Parts of the world such as oceanic islands the Arctic basin
and oases on the continents will still be habitable in a
hot world. We need to regard them as lifeboats and see
that there are sufficient sources of food and energy to
sustain us as a species. Physicians have the Hippocratic
Oath; perhaps we need something similar for our practice
of planetary medicine.

During the global heating of the early Eocene
there appears to have been no great extinction of species
and this may have been because life had time to migrate
to the cooler regions near the Arctic and Antarctic and
remain there until the planet cooled again. This may
happen again and humans animals and plants are
already migrating. Scandinavia and the oceanic parts
of northern Europe such as the British Isles may be
spared the worst of heat and drought that global
heating brings. This puts a special responsibility upon
us to stay civilized and give refuge to the unimaginably
large influx of climate refugees.

Perhaps the saddest thing is that if we fail and humans
become extinct the Earth System Gaia will lose as much
as or more than we do. In human civilisation the planet
has a precious resource. We are not merely a disease;
we are through our intelligence and communication the
planetary equivalent of a nervous system.

We should be the heart and mind of the Earth not its
malady. Perhaps the greatest value of the Gaia concept
lies in its metaphor of a living Earth which reminds us
that we are part of it and that our contract with Gaia is
not about human rights alone but includes human
obligations.