Geology Reference
In-Depth Information
cial periods, the whole world warms and the forest can just about manage to keep its
temperature within tolerable limits by frantically producing a thick sunshade of clouds.
But in our times, with more carbon dioxide in the air and higher temperatures than have
been seen on Earth for over 400,000 years, the forest can no longer cope. Soon it could
lose more water through evaporation than it can capture by triggering rainfall through
cloud formation, and could gradually dry out until a critical threshold is reached. Then
it would die back exponentially fast, just like white daisies when the sun pushes them
beyond their ability to regulate Daisyworld's temperature. The savannah which replaces
the rainforest seeds fewer clouds, so the entire Earth would warm as a massive temperat-
ure gradient builds up between the tropics and the high latitudes, creating severe storms
and hurricanes which wreak havoc over Earth's surface like demented genies bent on
revenge for the foolishness of our kind.
Meeting at the Heart of the World
Every denizen of the rainforest contributes to the production of clouds by the
forest as a whole, no matter how far removed from trees, bromeliad-dwelling al-
gae and clouds it might appear to be. Indeed, the whole planetary web of life en-
sures that the climate of the rainforest remains healthy enough for trees to send
their gifts of water and cloud-seeding chemical beings into the air.
I was once vouchsafed a special experience of one of these beings. I had joined
some friends on a six-week expedition to the remote Roraima region of Venezuela
adjoining the Brazilian Amazon. Conan Doyle had set his book 'The Lost World'
amongst the huge flat-topped mountains (tepuis) of this region. We had travelled
for about two weeks in a dugout canoe powered by a small outboard motor up the
Cuyuni river, camping on river beaches surrounded by
lush tropical forest. We had passed many tributaries flowing into this lovely river,
and finally we came to one that seemed especially inviting. It was dusk, and there
was a good beach for our camp that night, so we stopped, made our camp fire,
and decided that three of us would explore the tributary the next day using our
small inflatable dinghy and the outboard.
Next morning we set off early up the tributary, its waters softly braiding their way
down to the main river. It was gloriously sunny, and the trees on either side of
us glowed a luscious green as they drank in the life-giving sunshine. There was a
