| Until the end of the 20th Century, most scientists | | | | oceans, land masses and atmosphere. |
| thought they understood the nature of our | | | | However, with their old ideas now challenged by |
| climate system. As the very foundation of their | | | | these new theories, scientists began to notice the |
| science, geologists cherished the "uniformitarian | | | | evidence of abrupt changes in their data. Pollen |
| principle" that held that the fundamental forces | | | | records and improved carbon dating techniques in |
| that molded the Earth's features and climate were | | | | the 1970's depicted stable climate periods |
| gradual, natural, stable processes that did not | | | | interrupted by radical discontinuities that took only |
| vary over time scales less than tens of thousands | | | | one or two centuries to totally change the |
| of years. | | | | vegetation of a region. |
| This idea became central to their training through | | | | Since then, evidence from other studies such as |
| a century of debate over natural catastrophes | | | | cores of glacial ice and ocean sediments, has |
| such as the biblical account of Noah's flood. The | | | | continued to accumulate as methodologies have |
| concept of catastrophic climate change became | | | | been progressively refined. This has further built |
| 'tainted by association' with creationist zealots | | | | justification for heroic research, by intrepid teams |
| seeking scientific backing for fundamentalist | | | | braving hazardous conditions on heaving oceans or |
| interpretations of Bible passages. And so, such | | | | bitter, high altitude polar ice sheets, to win |
| stories came to be considered as purely | | | | samples deep and distinct enough to provide an |
| supernatural events, with no place within the | | | | unambiguous picture of the Earth's geological and |
| objectivity of science. | | | | climatic past, a picture that shows that violent, |
| Any evidence to the contrary...and there was, in | | | | spectacular short-term shifts were common. |
| retrospect, plenty of it... was at first readily | | | | As a result, scientists en masse were beginning to |
| dismissed. Sudden climate change in the Earth's | | | | entertain the possibility of abrupt change, this new |
| past was blurred by imperfect data and lack of | | | | attitude reflected in a statement from the |
| refinement in early scientific methods. Where | | | | Intergovernmental Panel on Climate Change in a |
| abrupt changes in the geological record were | | | | 1996 report that concluded that 'climate surprises' |
| indisputable, these were written off as regional | | | | were possible. The point was not emphasized at |
| curiosities, arising from purely local impacts - such | | | | the time, and received little press attention. Many |
| as a forest fire or the introduction of agriculture - | | | | scientists also passively rejected the facts by |
| impacts that had nothing to do with climate. | | | | refusing to revise their accustomed ways of |
| Until dating methods were perfected, chronological | | | | thinking about climate. |
| correlation of data collected at different locations | | | | Not until 2000 did paired ice-cores, extracted by |
| around the globe was not possible, and even | | | | competing teams in Greenland, match to show |
| when it was possible, was not at first even | | | | irrevocable proof of abrupt climate shifts taking |
| pursued. Global changes in climate had different | | | | effect over mere decades (see R.B. Alley's book |
| effects in different areas, further complicating the | | | | 'The Two-Mile Time Machine'). Similar cores were |
| issue and obscuring the true scope of abrupt, | | | | drilled in Antarctica and revealed the global scale |
| world-wide climate shifts. | | | | of the shifts. This forced the climate community |
| In fact, the uniformitarian climate paradigm was | | | | to arrive at consensus. |
| scarcely doubted until the 1950's when a group of | | | | Now respected climate scientists concur that the |
| scientists set up a physical ocean system model | | | | potential for fast climate change evidently does |
| that demonstrated that circulation could flip rapidly | | | | exist, and could surprise humanity with a climate |
| from one stable state to another. Scientists began | | | | shock within the lifetimes of you and I. However, |
| to concede that change may only take thousands | | | | the new paradigm has not extended beyond |
| of years. | | | | geoscientists to the impacts community - |
| This view of the change-rate capacity of climate | | | | economists and other specialists are slow to turn |
| was reduced to mere hundreds of years in | | | | their attention to the consequences of climate |
| subsequent decades, beginning in the early 1960's | | | | change, and policy makers and the public are even |
| when mathematical models that incorporated | | | | more ignorant of the risks humanity faces. |
| climate feedback factors such as snow and ice | | | | Because science has been late to wake up to |
| cover (albedo effects) suggested that global | | | | climate change, crucial information about the |
| climate really could change enormously in a | | | | potential behavior of our climate has only very |
| relatively short time. | | | | recently come to light. Relentlessly emerging |
| In the mid 1960's deep sea sediment cores finally | | | | climate surprises have thrown into painful relief |
| revealed that the planet had experienced several | | | | just how inadequate our understanding of the |
| ice-age cycles of gradual glacial buildups over | | | | climate system remains. Like a snowball rolling |
| 90,000 year intervals, punctuated by more rapid | | | | down a mountain, climate change is gathering |
| 10,000 year de-glaciations. Because of the huge | | | | momentum, racing ahead of even the most |
| lag between global climate shifts and deep sea | | | | pessimistic predictions. |
| temperature responses, even this data belied the | | | | Will you be ready? |
| extreme magnitude of changes on the surface | | | | |