Financial Times, 23 February 2018:

Sir, George Whitesides (Letters February 21) states that the “Blue
Marble” image of Earth, taken from space in 1972, gave rise to the
modern environmental movement. This overlooks the campaign by
Stewart Brand in 1966 to force Nasa to release a rumoured colour photo
of Earth. The image was subsequently used on the covers of Brand’s
seminal Whole Earth Catalog that offered tools for ecological living and
was published from 1969 to 1972. Greenpeace and Friends of the Earth
were founded in 1971. The great value of space access is that it is now
possible, using hyperspectral technology, to measure from space the
carbon flux on areas of Earth. This will make global carbon pricing and
trading viable as it brings scientific integrity to carbon sequestration
claims. Carbon markets have failed previously due to political
intervention and inaccurate measurement. Soil and forests, as carbon
sinks, are our main hope for reducing atmospheric greenhouse gas levels.
Satellites can help.

Craig Sams
Hastings, E Sussex, UK