Earth Regulation

Animation credit NASA

A synthesis by Antonio Donato Nobre, MCT – INPA Brazil Sponsored by the Global Canopy Program and the Foreign and Commonwealth Office, United Kingdom

Regulation of the Global Environment: A powerful Perspective

Presentation copyright © 2005 by MCT INPA/Antonio Donato Nobre

A multidisciplinary stroll through Earth evolution

Inharbors a small aregion in the outskirts heavenly cradle where… newborn baby-stars shine through clouds of dust a finger-like structure of gigantic proportions…

A baby star ejects a revolving disk of dust from which planets will form…

Billions of years and cosmic processes of unimaginable grandeur were required since the beginning of the Universe for the formation of our Galaxy…

Image credit NASA Huble Space Telescope

Sun

Earth

billions of years later… voilá, our solar system

Uranus

Why is there such a variety of planets? Mars

Venus

Jupiter

Saturn

Neptune

Why are rotations so different? planets in relative scale

Could other planets sustain life?

Image credit NASA

Diversity of Planets

Venus Searing 400O C sauna Clouds and rain of sulfuric acid 243 Days rotation Weak magnetic field Image credit NASA

Diversity of Planets

Mars Frigid Temperatures Magnetic field almost null Rarefied and un-breathable atmosphere

Image credit NASA

Diversity of Planets

Jupiter Moons

Image credit NASA

These These bodies bodies have have metallic water and nucleous ice

Io

Calisto

Europa

Ganimedes

Image credit NASA

Io, where geology is the “weather”

Thermal Image showing Active Volcanos

Image credit NASA

Europa, “iceball” There seems not to exist a rule for the formation of heavenly bodies in a planetary system. Some of Earth siblings are big and rocky, others are giant and liquid, yet others are small and frozen. Some have dense atmosphere, others lack it completely. Some are too hot, almost melting, others are too cold…

Image credit NASA

But only our mother planet is neither too big nor too small, so that it can hold an appropriately dense gaseous envelope; only here liquid water is found at the surface, indicating a narrow but confortable band of variations in temperatures; But to hold life, there are other cosmic issues to consider:

What about other heavenly objects?

What protects Earth from a continuous bombardment of meteorites?

An enormous swarm of moving boulders and comets, remnants from the formation of the solar system, lay floating in …some of which can, from outer orbits…

time to time, destabilize and plunge in our direction…

Jupiter and the other giant planets in outer orbits function as gravitational umbrellas, protecting Earth from comets and other wayward cosmic boulders

Comet Shoemaker-Levy impact 16-22 July/1994 Image credit NASA Huble Space Telescope

Earth Moon System Mass, distance and orbit of our Moon Thus, are the guarantees evolutionthe oflong the right term stability for the planet, in the right distance and orbit oblique angle of Earth rotational axis

from the sun, with the right set of neighboring planets attending necessary This dynamic rotation and sufficient conditions to stability for has Earth vital importance harbor forlife? the long term stability of climate

Not quite yet…

Image credit NASA

As a result of How theissolar Earth wind protected blasting its unprotected from the surface, erosive Ioforces loses matter of the to solar space… wind? Now the planet should be the right and stable body that will bear an atmosphere conducive to the appearance and evolution of life … But there is still a caveat…

Earth has a metallic nucleus. The inner core is solid, the outer core is molten and spins faster than the inner core…

Lines of Earth magnetic field, computer simulation

… like an electric motor, the differential spinning in the nucleus generates a big magnetic field that encompasses the whole planet…

... So, Earth’s magnetic field is very effective in protecting against the harshness of the solar wind...

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Animation credit NASA; ilustrates solar wind ejecting from the sun and being deflected by Earth magnetic field; ends with a view of Mars weak magnetic field

When the Solar wind hits the atmosphere on the poles, the Aurora lights indicate violent collisions of sun borne particles with atmospheric gases. Without the protection of the magnetic field these collisions would progressively dissociate gas molecules and eventually erode the atmosphere away from the planet.

If one were to calculate the numeric probability that all of these celestial factors would come together exactly right, as they did, the probability of Earth existence resulting from blind chance, multiplied by the probability of its actual characteristics, would very likely produce an infinitesimaly small number!

ATMOSPHERE EVOLUTION

The slow process of crafting an unlikely gas envelope…

In the beginning only geological and geochemical forces determined the Billions of years ago the accumulation and modification of gases in sun’s output was weaker so As happened in Venus and Mars, these the atmosphere. Greenhousepassive Earth the and greenhouse kept physical chemicalEarth processes 95% CO2 the oceans from freezing led to the accumulation of a reductive Venting from the Earth interior and atmosphere, mostly accretion fromcomposed meteorites were of theCarbon sources for the slowDioxide. buildup of gases on the planet’s surface

the transparent atmosphere But Earth evolved keeps the has oceans froman oxidative atmosphere, carbon boiling aswhere a result of a dioxide has been Present day Earth removed and reduced course stronger sunto traces. This 0.037% CO2 of evolution was radically different from the ones in Venus and Mars, which kept their reducive atmospheres unaltered to the present.

THE EARTH PARADOX

Had Earth kept the CO2 atmosphere of the beginning to the present, it would now resemble Venus, with extreme heat on the surface Had Earth had the low CO2 atmosphere of the present back in the beginning, it would now resemble Jupiter’s moon Europa, completely frozen

What process explain this severe atmospheric change? 30% output increase

Greenhouse Earth 95% CO2

Present day Earth 0.037% CO2

Purely passive production of O2 in the atmosphere does not explain the magnitude of reduction in CO2 concentration and the volume of molecular oxygen produced

MOLECULAR OXIGEN FORMATION BY WATER AND CO2 PHOTOLYSIS

Photochemical generation of molecular oxygen in the atmosphere could explain an amount equivalent to less than 1% of the present atmospheric concentration (21%)

However, most Oxygen produced over the ages (96%) was consumed in the oxidation of Iron and Sulfur on the Earth crust. Oxygen only started to buildup in the atmosphere when the crust was sufficiently “rusted”.

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Therefore, passive photochemical production of O2 would have had no chance of producing an oxidative atmosphere. By estechiometric analogy, the photochemical removal of CO2 could not explain the great reduction of this gas from 95% to 0.037%

Some geologists believe that weathering of continental rocks in a CO2 rich atmosphere with the ensuing formation of limestone would explain the removal of CO2 from the atmosphere…

The Mineral Carbon Conveyor Belt CaSiO3 + CO2  CaCO3 + SiO2 MgSiO3 + CO2  MgCO3 + SiO2

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this geological hypothesis is based in the accounting of huge volumes of limestone found on the ocean floors and also on previously flooded continental areas…

Continental Drift Internet material

Present 65 My 248 My

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540 My 740 My

… it also relies on the dynamism of the Earth’s crust that buries limestones and ejects new weatherable rocks continuously

Nonetheless, this geological hypothesis does not explain why and how the conveyor belt would not “saturate” (CO2 sunk equals CO2 erupted and degassed), and why sibling planets like Venus and Mars kept their atmospheres unaltered. Also, limestone is only a part of the story; vast deposits of organic carbon, like coal, oil and gas, are unequivocally connected to life…

How life would promote and control gas concentrations in the atmosphere? 30% output increase

Greenhouse Earth 95% CO2

PHOTOSYNTHESIS

Present day Earth 0.037% CO2

The emergence of photosynthesis in the biosphere explains the progressive consumption of atmospheric CO2 and symmetrical release of vast amounts of molecular oxygen

BLUEGREEN ALGI was the first organism to tap sunlight through photosynthesis

Over the ages the oxygen buildup in the atmosphere is consistent and synchronized with the evolution of organisms in the biosphere

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What is Photosynthesis? How does it tap light energy?

Why Carbon and Oxygen are different sides of the same coin?

Origin of All Organic Matter CO2 + H2O = CH2O + O2

Simple Explanation inert gas [CO2] is transformed into

sugar

...using for that nothing more than light and water

Chlorophyl: chemical solar panel

Light

H2

H2O ADP

O ATP

Light hitting the Hydrogen is chlorophyl produces remitted to the electricity innext its Finally, extra phase where it will other extremity, energy from light be used to reduce where water is then is packed into CO and produce 2 dissociated into ATP that will is be sugar; Oxygen Hydrogen and remitted to released into Oxygen the energize the atmosphere; sugar production Atmosphere phase

Rubisco: assembly line CO2

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Using energy and Hydrogen produced in the chlorophyl light phase, 6 CO2 molecules will now be “glued” together by the rubisco enzyme to form one molecule of Glucose

Mg

tein

Ru

pro bisco

Biochemistry: builds live complexity with simple building blocks Internet material

The most fantastic LEGO®!

Further on, glucose molecules are glued together by biochemical processes, producing celulose, lignin, wood... and then, with the addition of other ingredients, also proteins, lipids, vitamins... and a great variety of organic substances from which all organisms are made...

Organic substances have evolutive intelligence

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Natural selection and improved efficiency make organic substances able to control processes using stored evolutive information... CRISTALIZED ARGININE

Organisms are carbon super-structures of enormous complexity… Internet material

Manipulates flows of matter and energy Always seeks equilibrium Acumulates information Against disorder Self regulated

In hindsight, these inherent properties of life are veryThere similar is to overwhelming what can be seen in our planet evidence thatas a whole: many geological records point to a long lasting Earth is stable “because” it has life. stability of the Earth temperature, within very Blind geological or geochemical narrow limits of variation.

forces alone cannot explain the regulation in our Thisexquisite temperature stabilityveryfiable has maintained liquid water on the surface, an essential planet’s history.condition for life itself.

Runaway climates on all other known In many ways, the regulation of climate and the planets are powerful corroborations environment, as demonstrated by Earth history, is of the uniqueness of Earth’s self very similar to the complex and efficient regulation regulation capacity! of an organism own internal environment...

Paradise Earth?

“Every person, when made aware of the unbelievable work of Nature required in the generation and maintenance of that stability and comfort we enjoy today, will feel touched… becoming reflexive and speechless about the gigantism and complexity of life on Earth…”

Aknowledgements This synthesis work was funded by the Foreign and Commonwealth Office of UK, under a grant to the Global Canopy Prgram (www.globalcanopy.org/), and cosponsored by the National Institute for Amazonian Research in Brazil. Stimuli, support and a critical review from Andrew Mitchell from the Global Canopy Program was keenly appreciated. Most original material used in building of the slides came from public domain sites like www.nasa.gov and others. This synthesis could not have developed without inspiration by Robert Harriss (National Center of Atmospheric Research), Lynn Margulis (many of her books), Jim Lovelock (the Gaya Theory), Victor Gorshkov and Anastasia Makaraieva (Biotic Regulation of the Environment) and a number of authors in the scientific earth system and planetary science literature. This work was also spurred by 20 years of research in the magnificient Amazon rainforest, where environmental regulation is self evident. Socrates, thousands of years ago, first captured the notion that humankind only could properly evaluate the complexity of Earth if able to leave the planet and see it from the outside.