Presentation on theme: "THE LOOMING THREAT OF GLOBAL COOLING Geological Evidence for Prolonged Cooling Ahead and its Impacts Don J. Easterbrook Western Washington University."— Presentation transcript:
THE LOOMING THREAT OF GLOBAL COOLING Geological Evidence for Prolonged Cooling Ahead and its Impacts Don J. Easterbrook Western Washington University
THE PAST IS THE KEY TO THE FUTURE To understand present-day climate changes, we need to know how climate has behaved in the past. In order to predict where we are heading, we need to know where we’ve been.
“Our civilization has never experienced any environmental shift remotely similar to this. Today’s climate pattern has existed throughout the entire history of human civilization.” (Gore, 2006) “Temperature has spiked within the past few years unlike any previous temperature spike in history “ “Temperature has spiked within the past few years unlike any previous temperature spike in history “ (Mote, 2007) Current warming is 10 times greater than ever before seen in the geologic record”( “Current warming is 10 times greater than ever before seen in the geologic record” (Newsweek, August 13, 2007) Has climate always been constant before elevated atmospheric CO 2 ?
Natural global warming much more intense than modern warming has occurred many times in the geologic past without CO 2 change
Late Pleistocene abrupt climate changes ~15,000 yrs ago, a sudden (only a few years), intense climatic warming (~12° C; ~21° F) caused dramatic melting of huge Ice Age ice sheets. A few centuries later, temperatures again plummeted (~11°; ~20° F) and glaciers advanced. ~14,000 years ago, global temperatures rose rapidly (~4.5°C; ~8° F) and glaciers receded. ~13,400 years ago, global temperatures plunged (~8°C; ~14° F) and glaciers advanced. ~13,200 years ago, global temperatures increased rapidly (~5°C; ~9° F) and glaciers receded 12,700 yrs ago global temperatures plunged sharply (~8°C; ~14° F) and a 1000 year period of glacial readvance, the Younger Dryas, began 11,500 yrs ago, global temperatures rose sharply (~12° C; ~21° F), marking the end of the Younger Dryas cold period
Examples of past abrupt global climate changes before CO2 began to rise in 1945 Sudden warming 15,000 yrs ago at end of the Ice Age Dansgard-Oerscher events—Rapid warming in decades 13 Dansgaard-Oeschger events occurred between 11,600 and 45,000 years ago Younger Dryas -- Sudden warming 11,500 years ago -- 5°C over 30-40 years and ~8°C over 40 years. Medieval Warm Period 900-1300 AD Little Ice Age – Sudden cooling 400 years ago Historic fluctuations
25 yr warm/cool cycles from 18 O isotopes in the Greenland ice core
Medieval Warm Period and Little Ice Age Both Medieval Warm Period and Little Ice Age have long been well documented with strong geologic evidence. Georef lists 485 papers on the Medieval Warm period and 1413 on the Little Ice Age for a total of 1900 published papers. When Mann/Briffa contended neither had happened and climate had not changed in 1000 years, geologists didn’t take them seriously and thought either (1) the trees they used were not climate sensitive, or (2) they had used inappropriate data.
A group of scientists in the UK and US 1. Constructed a climate history that suppressed the Medieval Warm Period or the Little Ice Age, a major argument of CO2 advocates. 2. Doctored climate data to show increase global warming and suppress global cooling. 3. Hid or deleted data that didn’t support their beliefs. 4. Took over journal editorial boards to suppress opposing views. 5..Suppressed the research of scientists who didn’t agree with them 6. Reviewed their own publications and claimed only “peer reviewed” papers were valid
Two periods of global warming and two periods of global cooling have occurred in the past century
Correlation of glacial fluctuations, global temperature, and Pacific sea surface temperature
The Pacific Decadal Oscillation (PDO) The Pacific Ocean has two modes—a warm mode and a cool mode—and regularly switches back and forth between them on a 25-30 year cycle. The PDO has strong correlations with global climate—when the PDO is warm, climate is warm; when the PDO is cool, climate is cool.
Computer models are the only basis for claiming CO2 is causing global warming. IPCC models predicted 1ºF warming from 2000 to 2010. However, no warming beyond the 1998 level so the models have been proven wrong.
Impacts of global cooling Global cooling is far more harmful to humans than global warming because: 1. Twice as many people are killed by extreme cold than by extreme heat. 2. Decrease in global food production—hardest hit will be third-world countries where millions are now near starvation levels. 3. Increase in per capita energy demands. 4. Decreased ability to cope with the population explosion (>50% increase in next 40 years).
Conclusions Numerous, abrupt, short-lived warming and cooling episodes much more intense than recent warming/cooling occurred during the late Pleistocene, none of which could have been caused by changes in atmospheric CO 2.. Climate changes in the geologic record show a regular pattern of alternate warming and cooling with a 25-30 year period for the past 500 years. Strong correlation between solar changes, the PDO, glacier advance and retreat, and global climate allow us to project a consistent pattern into the future. Expect global cooling for the next 2-3 decades that will be far more damaging than global warming would have been.
Dogma is an impediment to the free exercise of thought. It paralyses the intelligence. Conclusions based upon preconceived ideas are valueless. It is only the open mind that really thinks. Patricia Wentworth, 1949
“Two things are infinite: the universe and human stupidity; and I’m not sure about the universe.” Albert Einstein.