The End of Earthly Oceans - Ocean Worlds: The Story of Seas on Earth and Other Planets - page 204

eastern seaboard of the US. On such an Earth, it will be deep water
or nothing.
With less water, the sea will likely be more salty. Worse: many of
the Earth's great stores of salts that were evaporated from the sea-
waters in 'saline giants' (Chapter 3) were stored on and around conti-
nental shelves. With these now standing high and dry and being
eroded, their freight of salt will wash into the sea to make the ocean
waters yet more briny. There will for sure be strong selective pressure
for organisms to keep pace, and to adapt to yet saltier waters (think of
the brine shrimps of the Great Salt Lake, for instance). Some will
manage to do this, but many will not.
It seems that oceans may not disappear into the Earth, but they
might be removed by other means.
A Hotter Sun and Thinner Blanket
Throughout its existence, the Sun has been very, very slowly becom-
ing hotter. Three billion years ago, as 'the faint young sun', it gave off
only about 80 per cent of the light and heat that it does today, and the
Earth and its oceans kept from freezing by having a thicker atmos-
pheric blanket of some combination of carbon dioxide, methane,
aerosols, and perhaps simply a higher atmospheric pressure made up
by more nitrogen.
In a billion years the Sun will be about 10 per cent hotter than it is
today, as more of its hydrogen is consumed. The Earth, therefore, will
inevitably become warmer than it is today. On that basis alone the
Earth should, over at least the first part of the next billion years to
come, become less prone to being glaciated and revert to conditions
akin to those of the Mesozoic, with little or no polar ice, high sea
levels, and flooded continents.
One consequence of warming, though, is that many chemical reac-
tions at the Earth's surface will take place faster—and one of these is