|
ISIS Special Miniseries - Life of Gaia
This miniseries is dedicated to our planet earth, so we may better
appreciate how she lives and sustains all creatures large and small, that we
may learn to dance to the complex rhythms of her life music without stopping
her in her tracks.
Space scientist and inventor Jim Lovelock first proposed in the 1970s
that the entire earth is a self-organizing, self-regulating entity, rather like
an organism. He named the earth Gaia, after the Greek earth goddess.
The idea that Gaia is alive and has a life of her own immediately caught
fire. It inspired many earth scientists to look for the dynamic processes that
organize and regulate the currents of the earth, to make a congenial home for
all her inhabitants. These scientists are richly rewarded.
Records from ice and deep sea cores show detailed globally correlated
changes going back at least 800 000 years, leaving us in no doubt that the
earth behaves from moment to moment as one coherent whole, just like an
organism.
Not only can we can read Gaia’s life-history from her deep memory
stores, we can also tune in to her life-force pulsing as she is living
today.
Gaia spinning in her perpetual dance around the sun, her mighty breath
tumbling from hot belly to the poles, swirling across the continents, bringing
welcome rain to forests, grasslands and crops, or torrential downpours, floods
and hurricanes. Vast slow vortices of water connect her oceans from the
furthest northern reaches to the southernmost haunts, from the shimmering sea
surfaces to the dark deep beds, distributing warmth and nutrients, sustaining
life with life.
Gaia’s breath is our breath, her water our water. Let Gaia live
that we may live.
Why the United States Needs the Amazon
The ‘Tele’connection
The US cornbelt will shrivel if the Amazon is destroyed. Peter
Bunyard reports.
Sources for this article are posted on ISIS Members’
website. Full details here
During the ‘Dust Bowl’ years of the 1930s, yields of wheat and
maize plummeted by 50 per cent as the soil just blew away in monstrous swirling
clouds, engulfing everything in their path. Hindsight tells us that much of the
horrors of those years resulted from putting the plough to wind-swept,
vulnerable soils that had never before been tilled. No hint of conservation
practices then, not like today. But just imagine how corn-belt farmers now
would react to being told that in the foreseeable future, a generation away at
best, their sons and daughters would be seeing their crops shrivel and die in
the baking sun, the precious soil once again blown away? And, we are not
talking of a year once every so often, but year after year in devastating
succession, turning what was the granary of the United States into desert.
So how come, given the difficulty we have of forecasting weather a few
days’ hence, let alone days, months, or even years away, that we can come
up with such dire predictions? It all comes down to what is happening thousands
of miles down to the south, in the Amazon, to the way that the forest, covering
nearly two million square miles, pumps water that has fallen as rain back into
the atmosphere (see "Why Gaia needs rainforests", this
series).
As Brazilian physicists have shown, more than half the rain that falls
over the Amazon either gets evaporated from the tree trunks before it ever
trickles to the ground or gets pumped out as vapour through the millions upon
millions of pores found in every leaf. This combined process of
evapo-transpiration puts back into the atmosphere more than 6 million million
tonnes of water vapour every year - equivalent to staggering amounts of energy
as the vapour condenses into rain. And it is that energy - captured as masses
of humid air – which brings heat and rain to more temperate parts of the
planet, and especially the Americas. Argentina gets no less than half of its
rain, courtesy of the Amazon. The United States, too receives its share of the
bounty.
Through an extraordinary process, recently unravelled by climatologists
in the United States, Brazil and Britain, we now know that what falls as rain
over the Amazon Basin is paralleled, three to four months later, in rain
falling over the US corn belt during its spring and summer.
‘Teleconnection’ is the name given to the process that transfers
energy and rain to the United States from Amazonia. Relatively slow-moving
moist masses of air, taking some months to complete their journey, seek
conduits in the atmospheric circulation system, pushing their way through
mass-circulation systems such as the Hadley Cell and the high flying
Easterlies. These waves of Amazonian air, fuelled by the water vapour they
carry, then release their rain en route over the corn-belt regions of
the US.
We are talking of the rains that are essential for the growth and
survival of crops fundamental to the needs of the United States, let alone the
rest of the world. Let the forest wither away, or just cut it and burn it down,
and the US as well as the world will suffer like no-one had ever imagined they
would.
The current US administration may have forgotten that in the drought of
1988, caused by a powerful El Niňo (see later), the United States had a
foretaste of what is to come. Corn yields fell by more than a quarter,
swallowing up the surpluses of previous years, and for the first time leaving
production behind US consumption. The federal government was forced to pay out
three billion dollars just in direct relief to farmers.
The irony is that much of the recent deforestation in the Brazilian
Amazon, particularly in the States of Mato Grosso and Para, is for growing soya
beans to meet the European demand for non-genetically modified produce, and in
addition, to feed China’s ever growing demands for soya-fed poultry and
pigs. What we now see, all too typically at Santarem in the State of Para, is
none other than thousands upon thousands of acres of monoculture soya,
stretching from horizon to horizon. The species-rich tropical forest has gone
forever (see "Soya destroying Amazon", this series).
Climatologists at the UK Met Office’s Hadley Centre have already
discovered that, as the world warms up, the air currents bringing rain to the
Amazon can suddenly switch El Niňo-like to a climate regime that is much
drier and warmer. In El Niňo years, the southern Pacific Ocean currents
reverse the normal east to west direction, with major impacts on climate across
the globe. Indonesia and Australia, instead of enjoying the low-pressure system
that brings tropical rains, find themselves burning in heat waves and having to
endure drought-conditions. On the other side of the Pacific, countries such as
Peru find themselves suffering torrential rain and warm coastal waters that
keep the nutrient-rich cold waters of the Humboldt Current at bay, with
plummeting fish-catches. During El Niňo years, the Amazon tends to dry out
as the rain-bearing air masses of the east to west circulation across the
equatorial belt are weakened and deflected. Moreover, it is likely to prove
highly destructive to the forest, through causing it to dry out, die-back and
become extremely vulnerable to fires.
As the forest withers back, its mass of carbon, some 200 tonnes for
each hectare, is decomposed into carbon dioxide and methane, so building up
still more the greenhouse gases in the atmosphere. With the forest virtually
all gone, more than 70 billion tonnes of carbon gases will find their way into
the atmosphere. From their projections of the consequences of greenhouse gas
build-up, Peter Cox and his colleague Richard Betts at the Hadley Centre are
projecting average global terrestrial temperatures to go up by nearly 9 C
before the end of this century from the pre-industrial levels of 150 years ago.
That level of warming was last evidenced more than 40 million years ago, when
neither of the Poles had permanent ice (see "Back to the
future for Gaia", this series) Sea levels were then more than a hundred
metre higher than today. At current greenhouse gas emission rates we have a few
decades at best before the forest begins its inexorable process of die-back and
decomposition.
The current frenzied destruction of the rainforest is very likely to
hasten the total collapse of the Amazon. Thunderstorms are the key to the
survival of the forest because they bring essential rain, in some parts of the
Amazon, as in Colombia, to the tune of 40 feet a year. Cut the forest down and
rainfall dwindles. That causes still more of the forest to die, so reducing
rainfall still further and bringing about a vicious cycle of spreading
degradation as fires begin to rage out of control. Recent research indicates
that more thunderstorms then brew because of the soot and ash in the air. The
result is more fire-inducing lightning strikes.
Climatologist Roni Avissar has discovered that the loss of rainfall is
not a smooth process related directly to the loss of forest. On the contrary,
interspersed clearings between large areas of forest cause rainfall over that
region to increase by as much as 30 per cent. The reason is that the clearing
heats up during the day, considerably more than the forest, which cools itself
through processes of evapo-transpiration. A mass of air then rises over the
clearing, being replaced by cooler more humid air that is drawn in from the
surrounding forest. As the now-moistened air rises it convects into massive
cumulo-nimbus thunderstorm clouds that then cause powerful downpours to drench
the land around. On that basis, modest-size clearings are not a disaster. The
forest can cope. On the other hand, make the clearing too big, say more than
100 kilometres across, and the forest can sustain its humidity no longer.
Literally, the convection process runs out steam and the number of rain-bearing
thunderstorms drops dramatically. This is yet another example of the
non-linear, threshold effects that can precipitate abrupt change.
We are now perilously close to the critical point in certain areas of
the Amazon, such as in Para, Rondonia and the Mato Grosso, when any further
loss of forest will lead to a dramatic decline in rainfall. And that, says
Avissar, will have a direct and dire impact on the United States. His models
show rainfall declining by as much as 15 to 20 per cent over agricultural
regions in the United States during the critical growing months - shades of the
Dust Bowl era all over again - once the Amazon collapses as a rainforest
system.
Whether it likes it or not, the United States is threatened on both
counts. First, because within decades from now the Amazon is likely to
self-destruct through being sucked dry by agro-industry. Second, the
accumulating impact of greenhouse gases in the atmosphere, is likely to lead
within the same time-span, to a sudden switch in air mass movements over the
Pacific and the Americas. Those El Niňo -like changes will also cause a
drying-out, accentuating the impact of those same agro-industrial clearings.
We don’t have to let it happen. To date, the United States has
acted with supreme selfishness in failing to ratify the Kyoto Protocol and so
reduce its excessive greenhouse gas emissions. It now needs to act with equal
selfishness in signing up to such Protocols; its own future is at stake. That
applies to all of us, in Europe, Asia, the Americas. We have a decade at best
to get our emissions in order. But, in no less measure we must all act to
ensure that the greater part of the Amazon is conserved. The reasons are
primarily for safeguarding our climate. In so doing we would naturally conserve
its extraordinary biodiversity - a diversity of forms that holds the fabric of
the forest together and is the key to a safer world.
Sources for this article are posted on ISIS Members’
website. Full details here
| |
|
