James Lovelock
(1919-2022)
James Lovelock was an English scientist, environmentalist and futurist. He is best known for proposing the
Gaia hypothesis, which postulates that the Earth functions as a self-regulating system.
Lovelock first formulated the Gaia hypothesis in the 1960s resulting from his work for NASA concerned with detecting life on Mars. The hypothesis proposes that living and non-living parts of the Earth form a complex interacting system that can be thought of as a single organism. He named it after the Greek goddess Gaia at the suggestion of novelist William Golding. The hypothesis also postulates that the biosphere has a regulatory effect on the Earth's environment that acts to sustain life.
Lovelock helped NASA to develop sensitive instruments for the analysis of extraterrestrial atmospheres and planetary surfaces, notable Mars] The Viking program, which visited Mars in the late 1970s, was motivated in part to determine whether Mars supported life, and some of the sensors and experiments that were ultimately deployed aimed to resolve this issue. During work on a precursor of this program, Lovelock became interested in the composition of the Martian atmosphere, reasoning that many life forms on Mars would be obliged to make use of it (and, thus, alter it). However, the atmosphere was found to be in a stable condition close to its chemical equilibrium, with very little oxygen, methane, or hydrogen, but with an overwhelming abundance of carbon dioxide. To Lovelock, the stark contrast between the Martian atmosphere and chemically dynamic mixture of the Earth's biosphere was strongly indicative of the absence of life on Mars.
An example of (dis-)regulation of the Earth's environment was Lovelock's detection of CFCs (chlorofuorocarbons ) in the atmosphere. He found a concentration of 60 parts per trillion of CFC-11 over Ireland and, in a partially self-funded research expedition in 1972, went on to measure the concentration of CFC-11 from the northern hemisphere to the Antarctic aboard the research vessel RRS Shackleton. The 1987 Montreal Protocol, an international treaty, phased out the production and use of CFCs, which were shown to deplete the ozone layer. However, the long atmospheric lifetimes of CFCs mean they will persist for decades, and their removal will be a gradual process.
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