2010 Diary week 32
Global warming, climate change and weather extremes
Book Review
The review of Why Geography Matters: Three Challenges Facing America: Climate Change, the Rise of China, and Global Terrorism by Harm de Blij will be found below. These are some snippets regarding climate change: “From about 10,000 years ago until today, humanity has thrived in the warmth of a prolonged interglacial, witnessing the emergence of complex cultures and civilizations, the population explosion, the formation of states and empires, the growth of megacities, and the burgeoning of technology.” “Global warming, starting about 18,000 years ago, was more than a temporary respite of the kind human communities living in high latitudes had experienced before. This time global warming was so powerful and persistent that glaciers melted fast, yielding enormous volumes of water that raised sea levels rapidly.” “About 12,000 years ago, one especially large ice sheet, the size of a large Canadian province, slid into the North Atlantic, chilling the ocean back to glaciation-time temperatures and causing more than a thousand years of cooling.” “By about 10,000 years ago, temperatures were back on the global-warming track.” “The warm period has now lasted more than 10,000 years. A final mass of ice sliding off northernmost North America not only cooled the ocean again but also sent a wall of water coursing through the Strait of Gibraltar into the Mediterranean Sea, overflowing its barrier with the Black Sea, filling the Black Sea at the rate of 6 inches per day, forcing inhabitants on the shore to back away about 1 mile daily.” “By the time it was over, the surface of the Black Sea had risen 500 feet and, quite possibly, the biblical legend of the Great Flood was born.” “Some societies found themselves in favourable locales and converted their good fortune into security, expansion, and power. Others saw rivers dry up, deserts encroach, and livelihoods destroyed.” “Climate change is almost always abrupt, shifting rapidly within decades, even years. It is unpredictable and sometimes vicious. The future promises violent change on a local and global scale. Such cycles are frightening to contemplate in an overpopulated and heavily industrialised world.” “The current global warming is likely to trigger rapid environmental shifts that could cause chaos on the planet. Ice cores from Greenland record wild fluctuations including slow warming and sudden cooling.” “The additional impact of human activity on the global atmosphere may trigger even more sudden climate change than prevailed long ago.”
WHY GEOGRAPHY MATTERS
THREE CHALLENGES FACING AMERICA
CLIMATE CHANGE, THE RISE OF CHINA. AND GLOBAL TERRORISM
HARM de BLIJ
Oxford University Press 2005
Chapter 1: Why Geography Matters
· Ten years ago it seemed that the world could not possibly change any faster than it had over the previous decade. Yet the pace of change straddling the turn of the century has not slowed down.
· Today geography has numerous dimensions, but it remains a great way to comprehend our complex world.
What is geography?
· Today geography is in a new technological age, with satellites transmitting information to computers whose maps are used for analysis and decision making. Geographers are especially well placed to assess the complicated relationships between human societies and natural environments.
But why is geography important?
· A general public not exposed to a good grounding in geography can be duped into believing all kinds of misinformation such as imminent glaciation (the 1960s) or looming greenhouse warming (the concern of the 2000s), leading to spending billions of dollars better invested in other causes.
Geographic literacy and national security
· Geographic knowledge is a crucial ingredient of our national security. We have crossed the threshold to a century that will witness massive environmental change, major population shifts, recurrent civilizational conflicts, China’s emergence as a geopolitical as well as an economic superpower, unifying Europe’s transformation into a major player on the international stage – among other developments yet unforeseen.
· Geographers are conducting research into the likelihood of coming energy crises and how to forestall them; on the risks of weapons of mass destruction and how to mitigate them; on the impact of global climate change and how to confront it.
Chapter 3: Earth’s Changeable Environments
· Few topics have aroused as much public debate and dispute over the past quarter century as global warming. It is not surprising that many people do not know whom to believe.
· If large percentages of Americans cannot identify major physical or political features on a blank map, even fewer could be expected to be able to outline the reasons why atmospheric pressure systems form and move the way they can or ocean currents flow the way they do.
· Get used to thinking in terms of millions and billions of years. One way to go about this is to relate our planet’s age to our own. If you are in your midforties a year in your life represents 100 million years of Earthly history; the emergence of modern humans has taken place in the last day of your life; the rise of modern civilization during the past hour.
· No matter what your age, the dinosaurs held sway until less than a year ago!
Dramatic beginnings
· Some 4,600 million years ago planet Earth congealed from an orbiting band of cosmic matter. When the Earth was 100 million years old, a large object, perhaps as large as Mars, struck at a low angle. The Earth had acquired its Moon.
· The Moon’s orbit grew progressively larger and the Earth’s rotation increased from about 4 hours to around 10 hours and the Earth’s crust began to cool.
· Earth’s continental land masses are continuously recycled. The familiar continental outlines we see on globes and atlases today are nothing like their antecedents three to four billion years past.
· The latest Pangean fragmentation began about 180 million years ago and continues today; plates collide, continental margins are pulled under, earth quakes and volcanic eruptions accompany the process. The earthquake that caused the December 26, 2004, tsunami was the result of such plate collision.
· We can now measure the movement of continents – about half an inch per year. The continental landmasses have moved thousands of miles since the breakup of Pangea started about 180 million years ago.
Oceans past and future
· Planet earth is often called the Blue Planet because more than 70% of its surface is covered by water. Mars may have lost a global ocean and there are indications that Mars at one time had even more water than Planet Earth
Ice on the globe
· The theory is known as Snowball Earth, and the evidence suggests that the Earth did not just cool, as has happened several times since: apparently the entire planet froze, from pole to pole and from land to sea.
· Several ice ages followed, and the most recent one is in progress right now. All known ice ages have periods of severe cold separated by shorter phases of comparative warmth.
· We are experiencing such a warm interruption at this time, one that has lasted roughly 12,000 years. But the ice age of our time began about 40 million years ago.
· Ice ages are times of accelerated evolution; organisms that adapt tend to survive, those that cannot, perish.
· There are indications that a huge meteor struck the earth about 251 million years ago, killing as much as 90% of all life on the planet. Scientists theorize that this may have been the most devastating of the Earth’s five known mass extinctions.
Sudden death
· The diversity of dinosaurs reached its zenith during the Cretaceous period when the world was warmer even than it is today.
· About 65 million years ago, a comet or asteroid only about 6 miles in diameter streaked towards the Earth at a speed of 55,000 mph, striking Earth in what is today the area of the Yucatan Peninsula of Mexico, forming a crater 110 miles in diameter and 40 miles deep.
· Debris reached half way to the moon before falling back to Earth. The atmosphere was heated enough to evaporate entire lakes, incinerate whole ecosystems, and extinguish most life.
· While some dinosaurs survived the original blast, food chains had been fatally disrupted and they, too, died out.
· The overheated atmosphere cooled, and the blockage of the sun sent temperatures plummeting, creating colder global conditions.
Back to the Future
· The impact greatly raised the amount of carbon dioxide in the air, creating a powerful greenhouse effect. The next epoch, the Eocene, was marked by an almost continuous drop in global temperatures; permanent ice was beginning to form. The Cenozoic Ice Age was about to start.
· Ice ages are not uniform cooling events: surges of coldness and advances of glaciers are interrupted by temporary warming spells long enough to reverse much of the glacial impact.
· About 14 million years ago, global cooling resumed with a vengeance. During the Pliocene epoch permanent glaciers appeared even on mountains in equatorial zones
· We are living under Pleistocene conditions today, enjoying the autumn of a warm phase that has been going on for about 12,000 years.
Climates and primates
· An ice age is a long-term event, lasting tens of millions of years and bringing profound changes to all parts of the planet, not just those directly affected by advancing ice sheet and valley-filled glaciers.
· There are times when sudden surges of advancing ice move fast enough to encircle grazing animals and snap off mature trees like matchsticks.
The frigid Pleistocene
· The temperature plunge that began in the late Miocene and continued during the Pliocene (when early hominids made their appearance in Africa) set the stage for the Pleistocene epoch, beginning less than 2 million years ago with a series of severe glaciations interrupted by short, warm interglacials.
· Early humans used the land bridge between Africa and Eurasia, across the Sinai Peninsular, late during the Eemian interglacial. No sooner were they in the Middle East when the Wisconian Glaciation began with a ferocious drop in temperatures. They never made it to Europe.
· The next time humans tried to leave Africa was around 85,000 years ago. The Wisconian Glaciation had converted so much water into ice that the surface of the Red Sea was hundreds of feet lower than it is today.
· Modern humans met the hominids who had preceded them into Eurasia and quickly overwhelmed them with their complex culture. Their technology gave them the opportunity to cope with the Wisconian’s climatic swings. Humans were finding ways to combat the rigors of changeable climate.
A close call
· A catastrophic event in what is today Indonesia very nearly wiped all of humanity off the planet when a volcanic mountain now named Toba in Sumatra exploded, sending millions of tons of debris into orbit, obscuring the Sun, plunging much of the Earth into long-term darkness and altering global climate. A large part of the still-sparse human population faced death.
· Our planet still poses unpredictable, incalculable natural hazards, as we were reminded on December 26, 2004.
· The relentless advances of the ice came again, and just 20,000 years ago, glaciers stood as far south as the Ohio River, southern England, central Germany, Slovakia, and Ukraine.
· About 18,000 years ago, global warming sent those glaciers into fast recession, so fast that whole regions rapidly emerged from under the ice, huge ice sheets slid into the oceans, the sea level rose, the margins of continents were submerged, land bridges between continents and islands were inundated, and the map of the physical world began to look similar to the one we know today.
· From about 10,000 years ago until today, humanity has thrived in the warmth of a prolonged interglacial, witnessing the emergence of complex cultures and civilizations, the population explosion, the formation of states and empires, the growth of megacities, and the burgeoning of technology.
· With our human numbers approaching 7 billion and global warming opening the last niches for habitation, the question is: what happens when the ice returns, as it has more than two dozen times during the Pleistocene?
Chapter 4: Climate and Civilization
· Global warming, starting about 18,000 years ago, was more than a temporary respite of the kind human communities living in high latitudes had experienced before. This time global warming was so powerful and persistent that glaciers melted fast, yielding enormous volumes of water that raised sea levels rapidly.
· To our Stone Age ancestors who had been living with the Wisconian’s variable climate, this warming must have been a welcome experience. But this time the warming was so persistent that people ventured farther and farther poleward.
One final surge
· About 12,000 years ago, one especially large ice sheet, the size of a large Canadian province, slid into the North Atlantic, chilling the ocean back to glaciation-time temperatures and causing more than a thousand years of cooling.
· By about 10,000 years ago, temperatures were back on the global-warming track.
Holocene humanity
· The warm period has now lasted more than 10,000 years. A final mass of ice sliding off northernmost North America not only cooled the ocean again but also sent a wall of water coursing through the Strait of Gibraltar into the Mediterranean Sea, overflowing its barrier with the Black Sea, filling the Black Sea at the rate of 6 inches per day, forcing inhabitants on the shore to back away about 1 mile daily.
· By the time it was over, the surface of the Black Sea had risen 500 feet and, quite possibly, the biblical legend of the Great Flood was born.
· Conditions stabilized into the Postglacial Optimum, starting about 7,000 years ago, transmuting into the Medieval Optimum, starting around 2,000 years ago, witnessing the peopling of Iceland and the colonization of Greenland.
· About 3620 BP (Before the Present) the volcanic island of Thira (Santorini), blew up covering a wide area of the eastern Mediterranean with a thick layer of poisonous ash, probably dealing a fatal blow to the powerful and culturally advanced Minoan civilization on Crete.
· Deglaciation continues long after the ice has disappeared: the poleward shift of climatic zones, the maturing of soils, the migration of plants and animals keep altering the environment for thousands of years.
· Some societies found themselves in favourable locales and converted their good fortune into security, expansion, and power. Others saw rivers dry up, deserts encroach, and livelihoods destroyed.
· Europe’s medieval cities mushroomed and the Tang Dynasty brought a golden age of expansion and consolidation, architecture and art.
· But not for long. In the west winters got colder. Early fall frosts led to local famines. Persistent droughts hit some parts of Europe; destructive floods struck elsewhere.
· By the turn of the fourteenth century, Alpine glaciers began to advance. Greenland’s small settlement disappeared; Iceland was abandoned. Weather extremes abounded.
The little ice age
· Increasing cold, decreasing rainfall, frigid winds, and shortened growing seasons made for dwindling harvests, failing farms, and seas too stormy for fishing.
· Famines struck all over Europe, just at a time when more people were clustered in towns than ever before. Europe’s climate fluctuated wildly, often suddenly, so that recovery would be followed by renewed famine, as populations mushroomed and then collapsed again.
· The Black Death swept over an already weakened Europe in waves that often killed half the population or more, and recovery, medical as well as environmental, did not start until the last quarter of the fifteenth century.
· Late in the fourteenth century the Ming rulers built a fleet of more than 6,000 ships. The Chinese seemed poised to round the Cape of Good Hope and enter the Atlantic.
· But then disaster struck at home. The first onslaught of the Little Ice Age came later than it did in Europe, but it was no less severe; the Ming rulers burned all ocean-going vessels, building barges for cargoes of rice to alleviate the plight of the colder, drier north.
· Environment may not determine the capacities of humans, but environmental events can decisively influence the course of history.
Crisis in Europe
· Western Europe’s Little Ice Age brought about the second Agricultural Revolution. Farm implements were improved; field methods got better; transportation and storage involved less waste and loss; new crops were tried; marketing become more efficient.
· All this was a matter of survival because the sixteenth century closed with one of the most extreme decades in Europe’s known environmental history, and during the seventeenth, conditions were worsened by a series of volcanic eruptions, precipitating colder spells in an already frigid region.
· The decade of the 1780s brought one crisis after another. A gigantic volcanic eruption on Iceland in 1783 lowered temperatures in North America by 7 degrees Fahrenheit, bringing a series of frigid winters in Europe, Russia, and North Africa.
· In February 1784, ice blocked the Rhine River, producing the worst floods in recorded history and causing food shortages and general economic distress. In 1788 hailstones 15 inches in diameter flattened crops. 1805 to 1820 was the coldest in the ‘real’ Little Ice Age when Napoleon’s armies invaded Russia.
Distant threat
· When it seemed that conditions could not get any tougher, they did – not because of an atmospheric event but a result of a volcanic eruption on the other side of the planet.
· On April 5, 1815, the Tambora Volcano located not far east of Bali, was pulverised when the top 4,000 feet was blown away and most of what is now Indonesia was enveloped in darkness for weeks; tens of thousands died of famine in the months that followed.
· By the middle of 1816, it was clear to farmers every where that this would be a year without summer. In Europe, food shortages were acute and grain prices rose rapidly, causing food riots. In New England corn would not ripen, grain prices escalated, and the livestock market collapsed.
The human factor
· As the Little Ice Age came to its mid-nineteenth-century end, the Industrial Revolution was gathering steam, the colonial era was transforming societies and economies, and population growth was accelerating.
· By 2015, two centuries after Tambora, the earth will carry seven times as many people as it did when that volcano exploded. How would the world cope today with a ‘year without summer,’ not to mention a Toba catastrophe – or a sudden return to Pleistocene glaciation?
Global warming?
· We appear to be experiencing a warming phase similar to the Medieval Optimum, the rate of temperature increase enhanced, this time, by human activity. We are headed for an uncertain environmental future.
· The effects of planetary temperature increases will be regional, not worldwide – as the severe 2003 heat wave in Europe, coinciding with unusual cool spells in parts of North America, underscored.
· Glaciers and ice caps are in retreat, agricultural frontiers are expanding, high-latitude seas are calmer and storms are fewer. At the same time, there is a rising incidence of extremes, of torrential rains in desert areas, parching droughts in humid zones, early autumn frosts and searing summer heat, intense tropical storms and early and late blizzards.
· Will we, in our enormous numbers, be able to adapt to rapid environmental change and chaos that attended the onset of the Little Ice Age?
· Climate change is almost always abrupt, shifting rapidly within decades, even years. It is unpredictable and sometimes vicious. The future promises violent change on a local and global scale. Such cycles are frightening to contemplate in an overpopulated and heavily industrialised world.
· The current global warming is likely to trigger rapid environmental shifts that could cause chaos on the planet. Ice cores from Greenland record wild fluctuations including slow warming and sudden cooling.
· About 5,000 years ago a northern cold spell coincided with the drying of the Sahara, converting it from a verdant landscape with rivers and lakes to the parched, rocky, and sandy wasteland it is today.
· It occurred over just a few decades, with far-reaching impact on the entire continent’s human geography.
· The additional impact of human activity on the global atmosphere may trigger even more sudden climate change than prevailed long ago.
· Sooner or later we will face extremes that come upon us quickly and will give little time to cope. We will depend on nature to sustain us.
· We will never be able to control climate change, but we may be able to mitigate it somewhat by limiting our greenhouse-gas emaciations.
· We should plan for worldwide coordination in the event of global natural emergencies caused by nature. An episode of rapid climate change poses as great a potential challenge to this nation as any it will face in the years ahead.
Climate and weather on the map
· Vladimir Köppen’s scheme to classify the world’s climates based on indices of temperature and precipitation – A: Equatorial, Tropical, Moist; B: Desert, Dry; C: Midlatitude, Mild; D: Continental, Harsh; E: Polar, Frigid; H: Highland – has stood the test of time.
· His map is worth a million words, because it allows us, at a glance, to determine what the prevailing climate is anywhere on Earth, and what we may expect in the way of weather under those climatic conditions.
· Geographers and others have been intrigued by the relationship between certain climates and certain successful, powerful societies. Equatorial and tropical climates do not favor the countries over which they prevail; none of the world’s major powers, present or recent, lie here. Desert climates also do not appear to be conducive to big-time status. The same seems true of high-latitude, polar climates.
· Ellsworth Huntington wrote in 1942: “The people of the cyclonic region (meaning the midlatitude cyclonic zones) rank so far above those of other parts of the world that they are the natural leaders. They lead in terms of productivity, but their greatest products are ideas and the institutions to which these give rise. The fundamental gift of the cyclonic regions is mental activity.”
· The seasonality of midlatitude climates favored peoples who remained for many generations under these demanding but stimulating regimes. He explained the rise and fall of societies in terms of the ‘sweep’ of climate change.
· It has all happened before – during the previous interglacial, the Eemian, it got so warm that sea level reached about 15 feet higher than it stands today.
· But the Eemian ended with a glacial bang, a return to glacial times so sudden that our ancestors emigrating from Africa froze in the Levant. What will the next millennium bring?
Chapter 5: A Future Geography of Human Population
The global spiral
· About 200 years ago, shortly after the onset of the Industrial Revolution, the Earth’s total population was only about 900 million.
· In 1820 the milestone of 1 billion was reached, and this number took 110 years to double. 43 years later in 1975, 2 billion doubled to 4 billion, and at present growth rates this number will double to 8 billion around the year 2035.
· Even as recently as 1650, the world’s human population was about 500 million – as many as are being added now every seven years or so.
Natural increase in regional perspective
· Regional rates of population change vary from Russia, decreasing at 0.7% annually to Subsaharan Africa, growing at 2.2% despite its terrible AIDS affliction.
· Even at a low of 0.7%, China is adding between 9 and 10 million people to its realm’s population – equivalent to a Sweden – every year.
The consequences for Europe
· The Earth’s total population by 2050 will approach 9 billion. The European Union will see their population decline from 482 million to 454 million in 2050.
· In Europe there are currently 35 people of pensionable age per 100 people of working age. By 2050 there will be 75 pensioners for every 100 workers. In Spain and Italy the ratio of pensioners to workers is projected to be 1:1. Labor unrest will become even more endemic in Europe than it already is.
· As Europe’s population shrinks and its proportion of the world population declines, dreams of an economic superpower fade. The implications of Europe’s demographic data are far reaching indeed.
Patterns of the future
· The populations of the rich countries today are growing at 0.25% annually and the poor countries at 1.46% annually. The populations of the 50 least developed countries of the world are growing by more than 2.4% annually.
· Of the projected 2.2 billion increase in population between 2000 and 2030, all but 100 million will crowd into cities.
· Conurbations of 50 million or more will anchor regions of India and China. Urban life will be the norm for the great majority in the future.
· The unanswerable question is how the countries of the richer world will relate to the overwhelming numbers and growing economic and military power of the currently poor.
Will the world’s population stabilize?
· Of the approximately 30% of the planet that is land, two-thirds is arid, frigid, mountainous, or otherwise inhospitable to large human numbers, providing ammunition for those who argue that overpopulation lies at the root of most of the world’s troubles.
Population and politics
· Burgeoning urban centers place enormous demands on rural areas in the form of food, water, and resources. People who move to the cities tend to start favoring more varied diets including more meats and poultry, resulting in deforestation in the countryside to make way for pastures.
· There is little point in making commitments to protect what remains of global natural environments without taking demographics into account.
· Overpopulation leads to economic conditions that generate desperate emigrations – and the migrants often cross American borders, creating an anti-immigrant feeling.
Population and the environment
· No species, not even the powerful dinosaurs of epochs past, has ever affected earthly environments as strongly as humans do today.
· Some biogeographers suggest that the next great extinction may be in the offing, caused not by asteroids but by humans.
· Malevolent destruction of the environment continues in various – indeed many – forms today and the consequences may be catastrophic.
The penalty of poverty
· In South Africa where 20% of all persons aged 15 to 49 may be infected with AIDS, life expectancy declined from 66 to 51 in just 10 years. In Botswana it fell from 60 to 39, a figure not seen since the Middle Ages.
· AIDS is killing parents in Africa at such a rate, that by 2010, it will have an estimated 20 million orphans, battering Africa’s already weak economies.
· 825 million people, a majority of them children, still suffer from malnutrition or worse.
· It is not enough to produce a quantity of food for people to sustain themselves; they must also be able to afford to buy it.
Momentous transition
· The world is in a momentous demographic transition. Optimistic projections suggest that the human population will never exceed 10 billion. Neo-Malthusians say that the planet should support no more than 2.5 billion.
· There is now some hope for the future, assuming the process is not derailed by some catastrophic event – a global natural disaster such as an asteroid impact, abrupt climate change, a pandemic of some unstoppable disease, an outbreak of nuclear war.
· It is conceivable that the world may be planning for ZPG (Zero Population Growth) in a half century or so. But who will do the work? How will the cost of longevity and lengthy retirements be paid?
· It is conceivable that hunger will have been defeated and the gap between the rich and the poor will narrow.
· Even as we catch a glimpse of light at the end of the population tunnel, the world is a far more volatile place, in which nuclear proliferation threatens, civilizational compulsions drive new forms of conflict, and economic globalization meets cultural mobilization on a new and dangerous battleground.