Global Warming

Global Warming Donald Rapp ⇐ From Al Gore’s film But CO2 is colorless 1 The Earth’s Climate Does Change! Independent of human impact 15,000 years ago So much of the Earth’s water was tied up in ice sheets that the level of the oceans was 350 ft lower The Mediterranean was dry and you could walk from Sicily to North Africa The temperature was about 10°C lower than today All of this occurred many times in the past - and all prior to large scale human impact 2 CO2 and T in Ice Age - Interglacial Cycles This peak occurs about 1000 yrs after T-peak Cause and Effect • Does rising CO2 cause warming or vice versa? • Al Gore and many climatologists say that CO2 causes interglacial warming • However, build-up of CO2 lags rise in T by about 1,000 years (or more) during interglacial warming periods T-peak 3 Broecker’s famous "Angry Beast" article • • [Broecker (1995)] likened the Earth's climate to an “angry beast.” He said: "…No one understands what is required to cool Greenland by 16°C and the tropics by 4±1°C, to lower the mountain snowlines by 900 m, to create an ice sheet covering much of North America, to reduce CO2 by 30%, …. If these changes were not documented in the climate record, they would never have entered the minds of the climate dynamics community. Models that purportedly simulate glacial climates do so only because key boundary conditions are prescribed (the size and elevation of ice sheets, sea ice extent, sea surface temperature, CO2 content, etc;) The current climate models do not explain and cannot reproduce the severe and abrupt climate changes in the proxy climatic record.” Bottom Line: Climate Modelers would never have imagined that ice ages could occur if the geologic evidence had not compelled them. 4 • • • • Fundamental Issues 1. How does recent global warming compare to natural fluctuations? a) b) c) Characterize measured earth temperatures: past ~ 120 years Use proxies to infer earth temperatures over historical time Compare recent ΔT with range of “natural” fluctuations Are we warmer today, or were they colder then? 2. 3. 4. 5. 6. 7. 8. How good were the “good old days” in the 19th century? • How has solar irradiance varied over time? What relevant changes occurred in the ocean currents? How reliable are climate models? What do they predict? How will limits on fossil energy supplies constrain future CO2 production? What are the claimed and credible future impacts of global warming? What public policy steps make sense? 5 Monitoring the Earth How well do we know how Earth temperatures have varied over the past ~ 120 years? 6 Temperature Measurement Stations Station Problems: (1) Changes in the observing time or instrumentation during the station’s history (2) Bias due to urban heating that evolved with time (3) Station moves or relocations (4) Poor siting due to nearby reflectors or impediments 7 Oceans = 70% of Earth area Urban Heating 8 U. S. Mean Temperature 5 year moving average Dip from 1940 to 1976 Annual 9 Hemispheric T Change Sharp rise after 1976 NH End of “little ice age” SH 10 Recent Trends Note peak in 1998: This brought forth prognostications of impending doom Note cold winter of 2007-8: Is this just a fluctuation? 11 Conclusion • The earth has warmed in the 20th century – More so in the northern hemisphere than the southern hemisphere – But not uniformly in space or time – Since 1976, warming has accelerated, after a dip from 1940 to 1976 12 Proxies to infer earth temperatures over historical time • • • • • • • Tree rings Ice cores Bore holes Corals Ocean sediments Pollen And many more … 13 How Proxies Work (or Don’t) Proxy Calibration Period Historical Proxy Measured T Year • • Compare proxy data with actual temperature measurements for calibration period - establish relation between T and proxy – – Typical calibration period: 20th century e.g. Tree rings: • • Effects of variable humidity and water supply Effects of CO2 fertilization Attempt to remove non-temperature factors • • Extrapolate relationship between proxy and temperature from 20th century backward in time – – – Assume relation between proxy and temperature is same for all time Other factors than temperature affect proxy Inherent noise in data All proxies suffer from various maladies 14 Typical individual proxy results • Mostly cooler prior to 1900 - “Little Ice Age” • Mostly warmer after 1900 but not at all sites • Large variations from proxy to proxy -Local variations or noise? • It may require many proxies to assess global T 15 MBH Models 1998-2006 • MBH integrated over 1000 proxies to estimate history of global average temperature over past 1000-2000 years – Utilizes deviations from mean temperature for calibration period – Use principal component analysis (PCA) to identify main trends in a noisy data set (applies weights to proxies) – Series of widely quoted published papers – Leads to “hockey stick” profile 16 MBH Result: The “Hockey Stick” Widely disseminated by MBH, Al Gore, the U. N., and other alarmists 17 McIntyre and McKitrick (2005-7) • PCA does not work right unless you use measure deviations from the mean for the entire data set (not just calibration period) • Based on calibration period mean, PCA inadvertently heavily weights the few proxies that rose in the 20th century - essentially eliminates almost all other proxies • These few proxies were tree ring data that were likely corrupted by CO2 fertilization in the 20th century • Hockey stick disappears if mean for the entire data set is used 18 A tale of two data processes MBH data processing with mean of calibration period Data processing with mean for entire data set 19 Integrating Multiple Proxies Burger & Cubasch: Examine procedure for reconstruction of historical temperatures from multiple proxies: 6 junctures with a fork in the road 26 = 64 ways to carry out the reconstruction 20 How unique is 20th century warming? Two alternate views of the past 1200 years ? ? 21 Evidence for MWP and LIA (one example) Sargasso Sea Sediments 22 Recent ΔT vs. “natural” fluctuations • Anecdotal evidence of MWP and LIA • Some proxies suggest a significant LIA and a MWP climate comparable to today Glacier Expansion and Retreat Retreat began in 19th century 23 How good were the “good old days” in the 19th century? • Are we warmer today, or were they colder then? • Does the 19th century provide a good baseline for comparison to an “ideal climate?” • Many anecdotal reports of punishing cold in 17th to 19th centuries; example: – "the removal of hundreds of thousands of beavers [to make furs for the cold middle and upper classes of Europe] during early Dutch and English colonial rule led to the extensive desiccation of wetlands in New England." – Presumably the removal of beaver-created dams on a large scale had a significant climatic effect on New England. 24 Variation of solar irradiance over time? • Solar cycle • Sunspot history • Total solar irradiance (TSI) – Observation in space since 1980 • Comparison to Sun-like stars • Earth temperature change: – ~ 0.2°C per W/m2 change in TSI • Solar contribution to climate change remains uncertain 25 Measurement of Total Solar Irradiance (TSI) 11 years Variance ~ 0.1% If this level of variation persisted in the past, solar variations would be too small to account for historical variations in temperature 26 Sunspot History The Sun has not been constant 27 Can we estimate past TSI? • Short answer is not very well (1) The "constant quiet Sun model" (2) The "solar diameter model" (3) The "activity envelope model” (4) The "umbra/penumbra (U/P) variations model" (5) The "MM temperature model" (6) The "Stellar Ca HK index model” (7) The "Solar cycle duration model" (8) The "Coronal source flux model" 28 Constant quiet Sun model • Use sunspot number as indicator of TSI • Note the current solar cycle varies from TSI = – 1367 W/m2 at ~ 150 sunspots at SMAX – 1365.5 W/m2 at < 10 sunspots at SMIN • Assume TSI = A + B*(SSN) • Estimate past TSI based on past SSN • TSI can NEVER drop below 1365.5 W/m2 • Other (non-CQSM) models allow greater past reductions in TSI • No model can be substantiated 29 Relevant changes in ocean currents • • • • • • The Southern Oscillation Index (SOI) is a measure of the differences in air pressure between Tahiti and Darwin, Australia. In general, changes in the SOI correspond very well with changes in ocean temperatures across the eastern tropical Pacific. The negative (positive) phase of the SOI coincides with abnormally warm (cold) ocean waters across the eastern tropical Pacific typical of El Niño (La Niña) episodes. Historically, + and - oscillations have occurred with ~ equal frequency In 1976, a rather sudden change took place and the SOI has been predominantly negative since then - Periodic upwelling of cold waters from the deep has rarely occurred Contribution to apparent global warming starting in 1976 may be significant – One interpretation: Earth is not getting warmer, but appears to be so since surface is warm and depths are cold – In a strong El Niño, the accumulation of excess heat in the eastern Pacific is about 1016 kWh 30 Southern Oscillation Anomaly "It is now widely accepted that a climatic regime shift transpired in the North Pacific Ocean in the winter of 1976–77.” "The 1970s North Pacific climate regime shift is marked by a notable transition from the persistent cooling condition over the eastern North Pacific since the late 1960s toward the opposite condition around the mid-1970s.... This large-scale decadal climatic regime shift has produced farreaching impacts...” "Several studies have noted that the pattern of (ENSO) variability changed in 1976, with warm events becoming more frequent and more intense. This 1976 Pacific climate shift has been characterized as a warming in SSTs through much of the eastern tropical Pacific." 31 How reliable are climate models? What do they predict? • • Global climate models divide the atmosphere into many small three-dimensional cells Within each atmospheric cell, the various parameters such as temperature, humidity, barometric pressure, and wind velocity are uniform, but are updated frequently Each cell interacts with its neighbors according to physical laws that are expressed as mathematical equations. Most models focus on predicted change in global temperature for doubling of CO2 from the pre-industrial era Some models are a priori; most have adjustable parameters There is no way to validate models 32 • • • • Models: ΔT produced by CO2 • • • Increased CO2 produces only modest direct warming This warming produces secondary effects of evaporating more water vapor Water vapor is a more potent greenhouse gas than CO2 and this is the cause of most of the putative global warming from CO2 in models Uncertainty in accounting for water vapor, clouds and aerosols leads to variability in predictions Over any significant time span, uncertainty in solar irradiance variation remains problematic ΔT due to doubling of CO2 has been predicted to be as low as 1°C or as high as 6°C, but average of predictions is around 3°C 33 • • • Rise in CO2 • There are some measurements that suggest much larger fluctuations in the past • Ice core measurements tend to incorporate samples over at least a 100 year period, leading to smoothing of fluctuations Doubling of pre-industrial would go to 550 ppm This is the most alarming aspect of climate change 34 Is increased CO2 a cause or effect of temperature rise? • In ice age-interglacial transitions (between ice ages) – CO2 changes lag ΔT changes by ~ 1000 years – CO2 changes from ~ 190 ppm to 280 ppm for ΔT of ~ 10°C • At present with CO2 at ~ 383 ppm, the Earth should be sweltering by comparison to interglacials between ice ages when CO2 was at ~ 280 ppm – But current temperatures are comparable to past interglacials • Plots of temperature rise, glacier contraction and sea level rise show increases long before major build-up of CO2 in atmosphere Temperature “dip” from 1940-1976 was during period of sharply rising CO2 – “Explanation” is aerosols 35 • Impacts of Global Warming Alarmist Claims • 1999 was the most violent year in the modern history of weather. So was 1998. So was 1997. And 1996 .... – A nine-hundred-year-long cooling trend has been suddenly and decisively reversed in the past fifty years .... – A climatological nightmare is upon us. It is almost certainly the most dangerous thing that has ever happened in our history. • Climate extremes would trigger meteorological chaos-raging hurricanes such as we have never seen, capable of killing millions of people; – uncommonly long, record-breaking heat waves; – and profound drought that could drive Africa and the entire Indian subcontinent over the edge into mass starvation. • From sweltering heat to rising sea levels, global warming's effects have already begun .... – The 1990s are likely to have been the warmest decade of the millennium in the Northern Hemisphere and 1998 is likely to have been the warmest year. • The IPCC took 1000 pages to describe all the impacts of global warming 36 Counter Arguments (1) There have always been fluctuations in the Earth’s climate. Today's warming lies within that range. (2) Hockey stick picture of the past millennium omits significant fluctuations in the past: little ice age (~1600 to ~1880) & medieval warm period (~850 to ~1050). (3) Evidence of global warming (glacier retreat, sea surface warming, ...) began prior to large-scale CO2 emissions and has not changed by increased CO2 emissions (4) There is no experimental proof that global climate models on heating effect of CO2 are correct. Wide variability from model to model suggests significant uncertainties in models. (5) Comparison of ice age - interglacial CO2 variation with current CO2 – – current CO2 is much higher than inter-glacials - why is it not hotter today? historical increases in CO2 occurred ~ 1000 years after temperature increases, suggesting increased CO2 is an effect of increased global temperature, not a cause. (6) Impacts of warming on humanity have been grossly exaggerated. (7) Economic cost of reducing CO2 emissions has been greatly underestimated. (8) Limitations of fossil fuel availability will constrain future CO2 emissions far below the projections of most global climate models. (9) The position of alarmists is akin to that of Earthquake scientists who predict: "the big one is coming" so "fund our research." If the problem were not cataclysmic, who would want to fund these people? 37 Warming Began Before CO2 38 Future Projections Limits on fossil fuel availability are likely to lead to results below the entire range in these figures 39 Kyoto Protocol • Developed countries must achieve reductions in greenhouse gas emissions – ~5% below 1990 or about 29% below that projected for 2010 • China, India and others can produce all the GHG they want to – But if they reduce emissions they can sell emission rights to developed countries • Kyoto acts as a scheme to slow the growth of the world's industrial democracies and transfer wealth to the third world. • The costs of the Kyoto Protocol outweigh the benefits, and the standards which Kyoto sets are too optimistic. • Kyoto punishes countries that have made progress in the past (Netherlands, France, …) by demanding even steeper cuts • China will soon become the world's greatest generator of greenhouse gases. China builds a new coal-fired power plant every week, and in a quarter of a century, its CO2 emissions will be double those of all the other industrialized nations combined. • “Nobody worries about conventional pollution” 40 Chairman Dingell's Energy and Commerce Committee • In October, 2007, Chairman Dingell's Energy and Commerce Committee of the U. S. Congress released its first white paper in a series on "Meeting the Climate Change Challenge.” "The United States should reduce its greenhouse gas emissions by between 60 and 80 percent by AD 2050 to contribute to global efforts to address climate change.” If a reduction from present levels, the reduction from business as usual in 2050 is 72 to 86% This program does not require that the United States supply its people and its industries with the energy needed to operate. It merely requires that emissions be reduced. An epidemic of insanity has apparently invaded the U. S. House of Representatives. Such a program will send the United States reeling back toward the lifestyle of the 18th century, bringing on a far worse economic depression than that of 1930s. • • • • 41 Alarmists vs. Naysayers • Both sides seem to be absolutely sure they are right – Despite the fact that not a single aspect of climate change can be unequivocally affirmed • • • • Temperature history (past millennium) Variability of the Sun (past and future) Impacts of warming on humanity Effects of CO2 on climate • • A little humility might go a long way in this arena Neither side seems to be able to shrug their shoulders and admit that we just don’t know the answers – So they adopt projections, extrapolations, hypotheses, unproven models, and guesses • Both sides appear to decide on conclusions in advance, and then craftily pick and choose data to back up their preconceived viewpoints - like lawyers, not scientists 42