November 9, 2011
Global Warming – Say your Goodbyes
The Present:
Gradual Warming
During the past 100 years, the surface of Earth has warmed, on
average, 0.8 degree Celsius (1.4 degrees Fahrenheit). Most of this
warming – that is, 0.6 degrees C. (1.0 F.) – has occurred during the
past 30 years. Thermal inertia dictates that, as of the year 2000,
Earth was committed to a further warming of 0.5 degrees C. (0.9 F.).
On a globe 4.0 degrees C. (7.0 F.) warmer than pre-industrially, the
chances are 66 percent that, in many areas, humans will not be able
to adapt. For natural systems, the chances are 50 percent that none
will be able to adapt, anywhere. Of the species which have been
assessed to date, some 40-70 percent would be at risk of extinction.
The concentration of atmospheric greenhouse gas is now higher than
it has been for at least the past 800,000 years. Sea level is rising by
0.3 centimeters a year. Ocean acidity is 30 percent more than it has
been for 30,000,000 years. Between 1970 and 2005, the power of
hurricanes in the North Atlantic and North Pacific oceans has doubled.
The Future:
Tipping Points
The gradual, steady, predictable warming of the past century, is unlikely to last.
The climate is a system composed of smaller systems, each with tipping points
able to precipitate wide, rapid swings of the whole. The past 250,000 years
have seen only two 10,000-year stable, warm periods – 130,000-120,000 years
ago, and the present Holocene Epoch, during which human civilization arose.
The worst case scenario is a shut down of the Gulf Stream due to low salinity
in the North Atlantic ocean, caused by melting of the Arctic Sea ice and
Greenland ice sheet. The Gulf Stream has already slowed down. Some 12,700
years ago, this particular system “tipped,” suddenly shutting off entirely, and
plunging Earth into the 1,300-year-long icy period known as the Younger Dryas.
Methane hydrate crystals, stored in frozen ocean sediments, also trigger a
vicious cycle when they melt, the released methane causing warming which in
turn causes more warming. Arctic Ocean methane stores are already melting.
Some 55,800,000 years ago, volcanic activity elicited this positive feedback,
warming Earth by 6 degrees C. (11 F.), and engendering mass extinction.
The ice-albedo feedback loop harbors a tipping point. At present, Earth’s
albedo (the amount of sunlight it reflects back into space), is 30 percent.
As snowcaps melt, however, and expose darker water and land,
reflectivity decreases, causing Earth to warm, and hence, more ice to melt.
The threshold of this system for runaway warming is presently unknown.
Another tipping point which Earth is approaching, is that of water vapor.
For every 1 degree C. (1.8 F.) of warming, the atmosphere
can hold 7 percent more water vapor. Water vapor is a powerful
greenhouse gas, which now accounts for 2/3 of the total heat trapped
by the atmosphere. More heat means more vapor, and hence, more heat . . .
Earth’s climate changes swiftly. In the ancient past, some regions
have warmed by 16 degrees C. (29 F.) in a decade. Weather patterns
can flip into a new state in three years. As a system, the climate partakes
of the property of all systems to have stretches of stability, punctuated
by, when pushed past a threshold, a rapid flip into a new stable state.
In the past 2,600,000 years (the Pleistocene Epoch), Earth’s climate has oscillated
between two states – “Cold,” with atmospheric carbon dioxide at 180 ppm, and
large polar ice caps; and “Medium,” such as until the year 1750, with atmospheric
CO2 at 280 ppm, and medium-sized ice caps. We are now entering a third state,
“Warm,” one which prevailed 35,000,000 years ago, with high CO2 levels, and no ice.
The
irreversibility of Carbon dioxide emissions
The ocean now absorbs 1/3 of human-engendered carbon dioxide emissions.
Warm water, however, holds less CO2, thus leaving more of the gas in the
atmosphere. Projections based on the 2011 concentration of atmospheric CO2
of 392 parts per million (ppm), rising at the rate of 2.2 ppm/year, reveal that
concentrations of 450 ppm could be reached by 2036, and 550 ppm, by 2050.
In contrast to other greenhouse gases, such as methane and nitrous oxide,
CO2 largely persists in the atmosphere for about 1,000 years. Equilibrium with
CO2 dissolved in the ocean takes 300 years; equilibrium with calcium carbonate,
both in the ocean and on land, takes 5,000 years; and the eventual removal of
the gas from the atmosphere by reaction with igneous rocks, takes 400,000 years.
On a human time scale, therefore, the emission of CO2 in the atmosphere
is essentially irreversible. Any emission warms the planet. Unfortunately,
humans have shown no sign of undertaking the drastic measures – such
as, for instance, a decrease in emissions of 3.5 percent per year – which
would be necessary to achieve a meaningful reduction of emissions to zero.
Goodbye to a
welcoming Biosphere
A system which is about to flip to a different stable equilibrium characteristically
shows instabilities and unusual variations. This is already happening to
our climate. Our climate has become volatile. Extreme events, such as
the European heat wave of 2003, are on the rise. Novel events, such as
the first-ever hurricane in the South Atlantic, in 2004, are on the increase.
For the biosphere, a catastrophe looms. We are in unchartered
waters. The past is only a rough guide to the future. It is probably
best to say goodbye now to who and what you love on this Earth.
The most adaptable species are those with a fast reproductive rate.
Among animals, these species are called pests or vermin; in the
sea, they are called slime; among plants, they are called weeds.
Goodbye to a large fraction of humanity,
to tigers, wolves, elephants, pandas,
whales,
polar
bears . . .
Greetings to rats, mice, beetles, jellyfish, algae, mosquitoes,
to microbes, kudzu, fleas, flies, ticks, cockroaches .
. .
References
Epstein, Paul, and Dan Ferber. 2011. Changing planet, changing health – How the climate crisis threatens our health and what we can do about it. Berkeley: University of California.
p. 2: This has raised the atmospheric carbon dioxide concentration by almost 40 percent over that of the pre-industrial era, to a level the planet has not seen for 30,000,000 years. (See also p. 136).
p. 35: Removal of top predators from food webs allowed the proliferation of pesky animals – like mice and rats – that could carry disease.
p. 68: Warmer air can hold more water vapor [7 percent more for every 1 degree C. (1.8 F.)]. (See also p. 196)
p. 72: Predictive climate models have been developed for several diseases. They rely not just on climate or weather data, but on biological indicators, such as the populations of rodents, algae, or mosquitoes that either transmit disease or indicate an epidemic is brewing.
p. 85: Under high CO2 conditions, which plants grow faster? It is the fast-growing, adaptable plants that thrive in disturbed environments – the plants we know as weeds.
p. 97: In 2003, a summer heat wave of unprecedented intensity blazed across Europe, killing more than 52,000 people . . . The probability of such extreme heat has already increased by between 2 and 4 times over the past century.
p. 114: 55,800,000 years ago, several trillion tons of CO2 were pumped fairly quickly into the atmosphere by an enormous burst of volcanic activity. During that time, known as the Paleocene-Eocene Thermal Maximum (PETM), temperatures spiked by 5 degrees C. (9 F.). (Note: This temperature increase was not used in the present poem. See p. 190 and Wikipedia, under “Paleocene-Eocene Thermal Maximum).
p. 116: Other pests and pathogens have also progressed northward with a warming climate.
p. 117: It’s the fast-growing, cross-breeding, genetically diverse denizens of a farm field – the weeds – that adapt readily.
p. 136: The world’s oceans are already 30 percent more acidic than they’ve been for eons. (See also p. 2).
p. 137: Thomas Lovejoy, President of the H. John Heinz III Center for Science, Economics and the Environment (a non-profit organization in Washington, D.C., named after Republican Senator H. John Heinz III, 1938-1991), predicted that acidification and reduced calcification could lead to a “reign of jellyfish.”
Ulf Riebesell (Professor of Biological Oceanography at the Leibniz Institute of Marine Sciences, Kiel, Germany) put it a bit more vividly. The future of the oceans, he said, will be marked by “the rise of slime.”
p. 151: How can we diagnose sick ecosystems? We can see if long-lived and specialist creatures are declining and being replaced by versatile generalists, like rats, jellyfish, or bark beetles. We can notice a shift of power in favor of prey over predators (such as mosquitoes over darning needles and lacewings); fast-growing, weedy plants over slower-growing plants; and microbes over larger, long-lived organism.
p. 170: In a 2005 paper, in Nature, Kerry Emanuel, (Director of the Program in Atmospheres, Oceans, and Climate, in the Department of Earth, Atmosphere, and Planetary Sciences), at the Massachusetts Institute of Technology, MA, found that the power dissipated by hurricanes in the North Atlantic and North Pacific oceans has nearly doubled over the 35 years since accurate satellite measurements became possible.
p. 187: Average temperatures rose fairly steadily through the 20th century, hiking the global average temperature about 0.75 degrees C. (1.4 F.). Sea levels have been creeping higher, now by 3 centimeters each decade.
p. 188: The far North Atlantic is already becoming measurably less salty, and recent studies suggest that the ocean conveyor, while variable, may already be slowing down . . . This actually happened about 12,700 years ago . . . It reversed the world’s warming, suddenly throwing it into a 1,300-year-long period of icy climates known as the Younger Dryas.
p. 190: The temperature was amazingly constant for the past 10,000 years, the Holocene era, in which human civilization arose. In contrast, temperature during most of the previous 250,000 years, had been marked by a series of sharp dips and rises (with the exception of one 10,000-year warm, inter-glacial period from 130,000 to 120,000 years ago). The stability of climate in our era – the Holocene – is an exception, not the rule.
Studies have demonstrated that the climate can change surprisingly fast. In the ancient past, some regions have warmed as much as 16 degrees C. (29 F.) in a decade. Weather patterns can flip into a new state in a little as three years.
This sort of behavior seems to be a property of systems in general: stretches of stability, then bursts of rapid change when systems are pushed past a tipping point.
Ways climate could change very rapidly:
1. Through calving and melting of icebergs and other increases of meltwater from the Greenland ice sheet. (See also p. 188)
2. A catastrophic release of methane. 55,000,000 years ago, a huge release of underwater methane caused temperatures to jump 8 degrees C. (14 F.), leading to a mass extinction. Today, there are already ominous signs that Arctic Ocean stores are being released, as warming waters cause the sea-bottom sediments to thaw. (Note: This temperature increase was not used in the present poem. See p. 114, and Wikipedia, under “Paleocene-Eocene Thermal Maximum”).
(p. 196) 3. Today, Earth’s albedo is about 30 percent, meaning that 30
percent of incoming sunlight is reflected back out into space,
primarily by ice and clouds.
4. Water vapor accounts for a remarkable 2/3 of the greenhouse effect. The atmosphere can hold more water vapor as it warms up – about 7 percent more per 1 degree C. (1.8 F.) of warming. (See also p. 68).
5. Another positive feedback involves the world’s oceans. Roughly a 1/3 of the CO2 emitted from factory smokestacks and automobile tailpipes now dissolves into the oceans, leaving less of this greenhouse gas in the atmosphere than there otherwise would be. Warmer water can hold less CO2 than cooler water.
p. 192: Carbon dioxide levels of 450 ppm, which we could reach in less than 3 decades, could warm the Earth enough to unlock large stores of methane in tundra and under seabeds . . . The current CO2 level is higher than it’s been for at least 800,000 years.
p. 197: The planet has oscillated, for 2,000,000 years, between two states: a cold state with large polar ice caps and about 180 parts per million CO2; and a warmer state, with medium-size ice caps and about 280 ppm CO2 – where we stood before the industrial revolution. Today’s atmospheric CO2 levels and temperatures are outside the limits that they’ve maintained for more than 2,000,000 years . . . We may even be headed for a third stable state, with elevated CO2 levels, much smaller ice caps, and significantly higher sea levels than we enjoy today.
p. 198: In recent years, scientists have noticed that the planet is changing more, and more quickly, than even the best climate models had predicted . . . There are characteristics of a system that may indicate how likely it is to change abruptly. The key is to watch for instabilities and variations. An increase in volatility may warn us that the planet’s climate is becoming less stable. This is already happening. On the rise are novel events and outliers . . . The European heat wave of 2003 was a major outlier. In 2004, the first-ever hurricane in the South Atlantic spun toward Brazil. Such signs of instability may augur bigger climate surprises to come. As we push CO2 levels higher than they’ve seen for millions of years, the past can only be a rough guide to the future. We are truly in uncharted waters.
p. 207: In a business-as-usual approach, CO2 levels could reach 550 ppm by 2050. (See also p. 273).
In the second scenario, ecosystems buckle. Pests and pathogens run unchecked and epidemics spread.
p. 273: James Hansen, [Director of the Goddard Institute for Space Studies, at the National Aeronautics and Space Administration (NASA)], . . . showed that 35,000,000 years ago, when the planet was ice-free, CO2 concentration stood at 450 ppm. Right now, we’re on track for 550 ppm CO2 levels – double pre-industrial levels – in 4 decades.
Pearson, Richard. 2011. Driven to extinction – The impact of climate change on biodiversity. New York: Sterling.
p. 17: Greenhouse gas concentrations are now higher than they have been for at least the last 800,000 years.
p. 19: The Intergovernmental Panel on Climate Change’s conclusion is that it is likely (probability of more than 66 percent) that extinctions could be on a scale of 40-70 percent, if the temperature increase exceeds 3.5 degrees C. (6.3 F.).
Pidwirny, Michael, and Scott Jones. 2006. “The Carbon Cycle,” in Fundamentals of physical geography. 2nd Edition.
http://www.physicalgeography.net/fundamentals/9r.html.
Carbon is stored on our planet in the following major sinks:
1. As organic molecules in living and dead organisms, in the biosphere.
2. As carbon dioxide in the atmosphere.
3. As organic matter in soils.
4. In the lithosphere as fossil fuels and sedimentary rocks (limestone, dolomite and chalk).
5. In the oceans, as dissolved atmospheric carbon dioxide and as calcium carbonate shells in marine organisms (coral, clams, oysters, some protozoa, and some algae).
Ocean deposits are by far the biggest sink of carbon on the planet.
Wikipedia, 2011.
“Carbon dioxide in Earth’s Atmosphere.”
The concentration of CO2 in Earth’s atmosphere is approximately 392 parts per million by volume, as of 2011, and rose by 2.0 ppm/year during 2000-2009. (Note: This rate of increase was not used in the present poem. The rate of 2.2 ppm, quoted further down in the article, was used).
The present level of CO2 is higher than at any time during the last 800,000 years.
CO2 has unique, long-term effects on climate that are largely “irreversible” for 1,000 years after emissions stop (zero further emissions). The greenhouse gases methane and nitrous oxide do not persist over time in the same way as CO2.
Three long term processes redistribute and eventually dissipate currently emitted CO2. Ocean absorption (300 years), a new equilibrium with calcium carbonate (5,000 years), and eventual reaction with igneous rock (400,000 years). These processes are so slow that, practically, zero emissions are at some point unavoidable in order to not exceed any practical CO2 concentration limit.
At the current growth rate, CO2 concentration will be 450 ppm in 22-27 years. The current growth rate is 2.2 ppm/year. To avoid dangerous climate change, a reduction in concentration of 3.5 percent per year needs to be achieved for the foreseeable future.
“Endangered Species,” “Critically endangered,” and “Vulnerable Species.”
“Global Warming.”
In the last 100 years, Earth’s average surface temperature increased by about 0.8 degrees C. (1.4 F.).
In a 4 degrees C. (7.2 F.) (warmer) world, the limits for human adaptation are likely to be exceeded in many parts of the world, while the limits for adaptation for natural systems would largely be exceeded throughout the world.
Climate commitment studies indicate that even if greenhouse gases were stabilized at 2000 levels, a further warming of about 0.5 degrees C. (0.9 F.) would still occur.
The average temperature of Earth’s surface increased by about 0.8 degrees C. (1.4 F.) over the past 100 years, with about 0.6 degree C. (1.0 F.) of this warming occurring over just the past 3 decades.
“Invasive Species.”
“Jellyfish.”
Jellyfish populations that have shown clear increases in the past few decades are “invasive” species, . . . with no natural predators.
The fact that jellyfish are increasing is a symptom of something happening in the ecosystem.
“Ocean Acidification.”
Between 1751 and 1994, surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14, representing an increase of 30 percent in “acidity” (H+ ion concentration) in the world’s oceans.
“Paleocene-Eocene Thermal Maximum.”
The most extreme change in Earth surface conditions during the Cenozoic Era began at the temporal boundary between the Paleocene and the Eocene Epochs, 55,800,000 years ago . . . Global temperatures rose by about 6 degrees C. (11 F.) over a period of approximately 20,000 years . . . The PETM is accompanied by a mass extinction of 35-50 percent of benthic foraminifera over the course of approximately 1,000 years . . . The most obvious feedback mechanism that could amplify the initial perturbation is that of clathrates. The PETM is accompanied by a mass extinction. (Note: This temperature increase is the one which was used in the present poem).
“Pests.”
Timeline
Years ago
55,800,000 Methane is released [the Paleocene-Eocene Thermal Maximum (PETM)].
35,000,000 The planet is in a “Warm” state – with no ice.
30,000,000 Ocean acidity same as today.
2,600,000 The Pleistocene Epoch. The climate oscillates between “Cold” and “Medium.”
800,000 Greenhouse gases same as today.
250,000 Since then, only two 10,000-year stable warm periods.
12,700 The Gulf Stream shuts off.
Now CO2 emissions.
+ 300 CO2 equilibrium between atmosphere and ocean.
+ 5,000 CO2 equilibrium between atmosphere and calcium carbonate (ocean and land).
+ 400,000 Removal of CO2 from the atmosphere by reaction with igneous rocks.
* * *