2010 Diary week 33
Global warming, climate change and weather extremes
Book Review
Below you will find the review of Part 1 of With Speed and Violence: Why Scientists Fear Tipping Points in Climate Change by Fred Pearce. These are some snippets: “The Greenland Sea occupies a basin between Greenland, Norway, Iceland, and the Arctic islands of Svalbard. It is like an antechamber between the Atlantic and the Arctic Ocean: the place where Arctic ice flowing south meets the warm tropical waters of the Gulf Stream heading north.” “The unique mix of warm tropical waters and arctic ice is the key to a hidden secret called ‘the chimney.’ Only a handful of people have ever seen this giant whirlpool in the ocean, 6 miles in diameter, constantly circling counterclockwise and siphoning water from the surface to the seabed 2 miles below. That water will not return to the surface for a thousand years.” “The chimney, once one of a family, may be the switch that can turn the heat engine of the world’s climate system on and off.” “The existence of a series of these chimneys was discovered by Peter Wadhams in the 1990s. He concluded that they were the final destination for the most northerly flow of the Gulf Stream.” “‘In 1997 we found four chimneys in a single season, and calculate there could have been as many as twelve.’ Since then, they have been disappearing one by one – except for one particularly vigorous specimen.” “He sent submersible instruments down to measure its motion at depth. It rotated right down to the ocean floor, and such was the force of the downward motion that it could push aside a column of water half a mile high. The physics of how it did it is not understood at all.” “The great chimney had in May 2003 one dying companion, almost certainly in its death throes. That left just one remaining chimney in the Greenland Sea. It too may be gone by now. We just don’t know.”
WITH SPEED AND VIOLENCE
WHY SCIENTISTS FEAR TIPPING POINTS IN CLIMATE CHANGE
FRED PEARCE
BEACON PRESS 2007
PART I
Chronology of Climate Change
5 billion years age: Birth of planet Earth
600 million years ago: Last occurrence of ‘Snowball Earth,’ followed by warm era
400 million years ago: Start of long-term cooling
65 million years ago: Short-term climate conflagration after meteorite hit
55 millions years ago: Methane ‘megafart’ causes another short-term conflagration
50 million years ago: Cooling as greenhouse-gas levels in air start to diminish
25 million years ago: First modern ice sheet starts to form on Antarctica
3 million years ago: First ice-sheet in the Arctic ushers in era of regular ice ages
100,00 years ago: Start of most recent ice age
16,000 years ago: Most recent ice age begins stuttering retreat
14,500 years ago: Sudden warming causes sea levels to rise by 65 feet in 400 years
12,800 years ago: Last great ‘cold snap’ of the ice age, known as the Younger Dryas era, is triggered by emptying glacial lake in North America and continues for around
1,300 years before ending very abruptly
8,200 years ago: Abrupt and mysterious return to ice-age conditions for several hundred years, followed by warm and stable Holocene era
8,000 years ago: Storegga landslip in North Sea, probably triggered by methane clathrate releases that also bolster the warm era
5,500 years ago: Sudden aridification of the Sahara
4,200 years ago: Aridification in the Middle East; collapse of civilizations
1,200 to 900 years ago: Medieval warm period in the Northern Hemisphere; Megadroughts in North America
700 to 150 years ago: Little ice age in the Northern Hemishere, peaking in the 1690s
1896: Svante Arrhenius calculates how rising carbon dioxide levels raise global temperatures
1938: Guy Callendar provides first evidence of rising carbon dioxide levels in the atmosphere, but findings ignored
1958: Charles Keeling begins continuous monitoring program that reveals rapidly rising carbon dioxide levels in the atmosphere
1970s: Beginning of strong global warming that has persisted ever since, almost certainly attributable to fast-rising carbon dioxide emissions, accompanied by shift in state of key climate oscillations such as El Niňo and the Arctic Oscillation, and increased melting of the Greenland ice sheet
Early 1980s: Shocking discovery of Antarctic ozone hole brings new fears of human influence on global atmosphere
1988: Global warming becomes a front-page issue after Jim Hansen’s presentations in Washington, D.C. during U.S. heat wave
1992: Governments of the world attending Earth Summit promise to prevent ‘dangerous climate change’ but fail to act decisively
1998: Warmest year on record, and probably for thousands of years, accompanied by strong El Niňo and exceptionally ‘wild weather,’ especially in the tropics; major carbon releases from burning peat swamps in Borneo
2001: Government of Tuvala, in the South Pacific, signs deal for New Zealand to take refugees as its islands disappear beneath rising sea levels
2003: European heat wave – later described as the first extreme weather event attributable to man-made global warming – kills more than 30,000; a third of the world is reported as being at risk of drought: twice as much as in the 1970s
2005: Evidence of potential ‘positive feedbacks’ accumulates with exceptional hurricane season in the Atlantic, reports of melting Siberian permafrost, possible slowing of ocean conveyor, escalating loss of Arctic sea ice, and faster glacial flow on Greenland
The cast: Richard Alley; Svante Arrhenius; Gerald Bond; Wally Broecker; Peter Cox; James Croll; Paul Crutzen; Joe Farman; Jim Hansen; Charles David Keeling; Sergei Kirpotin; Michael Mann; Peter deMenocal; John Mercer; Drew Shindell; Lonnie Thompson; Peter Wadhams
Preface: The Chimney
· The Greenland Sea occupies a basin between Greenland, Norway, Iceland, and the Arctic islands of Svalbard. It is like an antechamber between the Atlantic and the Arctic Ocean: the place where Arctic ice flowing south meets the warm tropical waters of the Gulf Stream heading north.
· 200 years ago, the sea was a magnet for sailors intent on making their fortunes by harpooning its great schools of bowhead whales.
· William Scoresby, who landed a world-record 36 whales in 1798 was too clever for his own good, and the boom turned to bust when all the whales had been killed.
· Just as the unique mix of warm tropical waters and arctic ice was the key to the Greenland Sea’s whaling bonanza, so it is the key to another hidden secret of these distant waters.
· It’s called ‘the chimney.’ Only a handful of people have ever seen this giant whirlpool in the ocean, 6 miles in diameter, constantly circling counterclockwise and siphoning water from the surface to the seabed 2 miles below. That water will not return to the surface for a thousand years.
· The chimney, once one of a family, pursues its lonely task in the middle of one of the coldest and remotest seas on earth. And its swirling waters may be the switch that can turn the heat engine of the world’s climate system on and off.
· The existence of a series of these chimneys was discovered by Peter Wadhams in the 1990s. He concluded that they were the final destination for the most northerly flow of the Gulf Stream.
· The chimneys were, Wadhams realized, the critical starting point of a global ocean circulation system that oceanographers had long hypothesized but had never seen in action.
· Wadhams knew they were in trouble, for the Arctic ice was disappearing. By the end of the 1990s, the Odden tongue was gone. The Gulf Stream water still came north, but it never again got cold enough to form ice. The ice tongue has not returned.
· “In 1997, the last year that the Odden tongue formed, we found four chimneys in a single season, and calculate there could have been as many as twelve.” Since then, they have been disappearing one by one – except for one particularly vigorous specimen.
· By rights, it should not have been there without the ice. But it was, hanging in there, propelled downwards perhaps by the saltiness created by the evaporation of the water in the wind.
· He sent submersible instruments down to measure its motion at depth. It rotated right down to the ocean floor, and such was the force of the downward motion that it could push aside a column of water half a mile high. The physics of how it did it is not understood at all.
· The great chimney had in May 2003 one dying companion, almost certainly in its death throes. That left just one remaining chimney in the Greenland Sea.
· It too may be gone by now. We just don’t know. Like Scoresby’s bowheads, it may disappear unnoticed by the outside world. Or we may come to rue its passing.
Introduction
· I like to question everything. Sometimes condemning the politics of demographic doomsday merchants is bad for business.
· But climate change is different. I have been on this beat for 18 years. The more I learn, the more I go and see for myself, and the more I question scientists, the more scared I get. It is our own survival that is at stake, not that of a cuddly animal or a natural habitat.
· Don’t take my word for it. Often it is the professors with the best CVs who are the most fearful, often talking in the most dramatic language.
· Nature is strong and packs a serious counterpunch. Its revenge for man-made global warming will very probably unleash unstoppable planetary forces. And they will not be gradual.
· The history of our planet’s climate change shows that, under pressure, it lurches, virtually overnight.
· We humans have spent 400 generations building our current civilization in an era of climatic stability – a long and generally balmy spring that has endured since the last ice age. The exception rather than the rule in nature.
· This book is a reality check about the state of our planet. That state scares me, just as it scares many of the scientists I have talked to – sober scientists, with careers and reputations to defend, but also with hopes for their own futures and those of their children, and fears that we are the last generation to live with any kind of climatic stability.
· One told me quietly: “If we are right, there are dire times ahead. Having a daughter who will be about my present age in 2050, and will be in the midst of it, makes the issue more poignant.”
PART I. WELCOME TO THE ANTHRPOCENE
Chapter 1: The Pioneers. The men who measured the planet’s breath
· On December 24, 1894, Svante Arrhenius settled down at his desk and began a marathon of mathematical calculations that took him more than a year. What spurred his work was the urge to answer the riddle of the day: how the world cooled during the ice ages.
· Arrhenius reckoned the clue lay in gases that could trap heat in the lower atmosphere, changing the atmosphere’s radiation balance and altering temperatures.
· When he emerged from his labors, he was able to tell the world that a reduction in atmospheric carbon dioxide levels of between a third and a half would cool the planet by about 8 degrees Fahrenheit – enough to cover most of northern Europe in ice.
· He also concluded that a doubling of atmospheric carbon dioxide would raise world temperatures by an average of about 10ºF – almost exactly mirroring the Intergovernmental Panel on Climate Change’s most recent assessment.
· He offered more predictions that are reproduced by modern computer models. High latitudes would experience greater warming than the tropics; warming would be more marked at night than during the day; in winter than in summer; and over land than over sea.
· Guy Callendar, in a lecture at the Royal Meteorological Society in 1938, reported that carbon dioxide levels in the atmosphere showed a 6% increase since 1900 due to fossil fuel burning.
· Charles David Keeling monitored carbon dioxide levels in the clean air 14,000 feet up on the top of Mauna Loa, a volcano in Hawaii, every four hours, identifying a background level of 315 ppm, that fluctuated between winter and summer due to photosynthesis.
· The concentration rose steadily from 315 ppm in 1958 to 320 ppm in 1965, to 331 ppm in 1975 and to 380 ppm today.
· Before his death in 2005 he announced that, for the first time, his instruments had recorded two successive years, 2002 and 2003, in which background carbon dioxide levels had risen by more than 2 ppm.
· Only in the past 5 years, have some researchers concluded that changes probably won’t be smooth or gradual as the scenarios drawn up by the IPCC still suggest.
· We are in all probability already embarked on a roller-coaster ride of lurching and sometimes brutal change. What that ride might feel like is the central theme of this book.
Chapter 2: Turning Up the Heat. A skeptic’s guide to climate change
· To summarize the current state of affairs: the global trends are real; no known natural effect can explain the global warming seen over the past 30 years; natural changes like solar cycles would have caused cooling; changes in greenhouse gases are the simple, least convoluted explanation for climate change; and those changes are predominantly man-made.
· Big uncertainties remain about how the planet will respond to more greenhouse gases as positive feed backs reinforce and amplify change and run the risk of producing runaway change.
· The IPCC could be underestimating the threat the world faces.
Chapter 3: The Year. How the wild weather of 1998 broke all records
· Hurricane Mitch was the most vicious hurricane to hit the Americas in 200 years, dumping a year’s rain in a few hours. The question is not: Can we prove that events like Mitch are caused by climate change? It is: Can we afford to take the chance that they are?
· 1998 was the warmest of the century, perhaps of the millennium. It was also a year of exceptionally wild weather: rainforests got no rain; forest fires of unprecedented ferocity occurred in Borneo, Brazil, Peru, Tanzania, Florida and Sardinia; New Guinea had the worst drought in a century; East Africa had the worst floods in half a century during the dry season; much of the desert north of Uganda was flooded; Mongol tribesmen froze to death as Tibet had its worst snows in 50 years; the water level in the Panama Canal was so low that large ships couldn’t pass; ice storms disabled power lines in New England and Quebec; the coffee crop failed in Indonesia; cotton died in Uganda; fish catches collapsed off Peru.
· If you want to know what the first stage of climate change is shaping up to be like, look no further than 1998.