Gaia Theory

Overview

According to biologist James Lovelock, Gaia theory refers to "all parts of the earth -- the living and nonliving make up a single giant self-regulating organism that maintains and stabilizes the conditions suitable for life on Earth" (Hendry 72 ). Put differently, Gaia theory frames the earth as a superorganism that changes to support life through adjustments to the environment.

Controversial Aspects

Gaia theory is controversial for a few reasons. First, it's not a "theory" in the same sense as other scientific theories (i.e., "Gaia theory" is not easily falsifiable, so the name is slightly misleading). Second, Gaia theory arguably implies an "ends" or teleology of nature -- a goal or intention -- which undercuts the random mutations that occur in natural selection. Third, climate change deniers can easily co-opt ideas from Gaia theory to downplay the significance of global warming.

Ahead of Its Time?

Nevertheless, Gaia theory anticipated key developments in climate science and Earth system science. In particular, Lovelock helped to explain how surface temperature and ocean salinity remained so constant through "feedback loops" that allow for planetary homeostasis (to a degree).

Examples of Gaia Theory

• the regulation of the Earth's surface temperature.

• ice ages, after which the world temperature and life changed along to survive. This includes ocean temperatures and salinity.

• the survival and adaption of life after extinction events.

References 

Hendry, Judith. Communication and the Natural World. Strata, 2010.

https://www.open.edu/openlearncreate/mod/oucontent/view.php?id=22639&printable=1