In a fiery speech yesterday, Sen. Sheldon Whitehouse (D-R.I.) ”calls out” “climate deniers.” In the first half of the speech he goes ad hominem, attacking opponents as “front groups” who take payola from “polluters” to “confuse” the public by selling “doubt” as their product.

First a bit of free advice for the good Senator:

Your team has been playing nasty from day one. It didn’t get you cap-and-trade, it didn’t get you Senate ratification of the Kyoto Protocol, and it’s not going to get you a carbon tax.  

Vilification doesn’t work because biomass, wind turbines, and solar panels are not up to the challenge of powering a modern economy, and most Americans are too practical to believe otherwise.

So by all means, keep talking trash about your opponents. The shriller your rhetoric, the more skeptical the public will become about your bona fides as an honest broker of “the science.”

Okay, let’s examine Sen. Whitehouse’s argument. He accuses skeptics of peddling “straw man arguments,” such as that “the earth’s climate always changes; it’s been warmer in the past.” Well, it does, and it has! Many studies indicate the Medieval Warm Period (MWP) was warmer than the current warm period (CWP). A study published in July in Nature Climate Change concludes the Roman Warm Period (RWP) was warmer than both the MWP and CWP. The Northern Hemisphere was substantially warmer than the present for thousands of years during the Holocene Climate Optimum (~5,000-9,000 years ago). Arctic summer air temperatures were 4-5°C above present temperatures for millennia during the previous interglacial period.

None of this is evidence man-made global warming is not occurring, but Sen. Whitehouse sets up his own straw man by making that the main issue in dispute. What the paleoclimate information does indicate is that the warmth of the past 50 years is not outside the range of natural variability and is no cause for alarm. The greater-than-present warmth of the Holocene Optimum, RWP, and MWP contributed to improvements in human health and welfare. 

Sen. Whitehouse says skeptics also knock down a straw man when they deny extreme weather events prove the reality of climate change. “No credible source is arguing that extreme weather events are proof of climate change,” he states. Again, it’s Sen. Whitehouse who whacks a man of straw. The problem for skeptics is not that people like Al Gore or the editors of Bloomberg cite Hurricanes Katrina or Sandy as “proof” of global warming, it’s that they blame global warming (hence “polluters”) for Katrina and Sandy. They insinuate or even assert that were it not for climate change, such events would not occur or would be much less deadly. As the Senator does when he says climate change ”loads the dice” in favor of events like Sandy and is “associated with” such events.

I freely grant that heat waves will become more frequent and severe in a warmer world (just as cold spells will become less frequent and milder). However, there is no persuasive evidence global warming caused or contributed significantly to the European heat wave of 2003, the Russian heat wave of 2010, the Texas drought of 2011, or the U.S. midwest drought of 2012. A slew of scientific papers finds no long-term trend in Atlantic hurricane behavior, including a recent study based on 370 years of tropical cyclone data. Similarly, a U.S. Geological Survey study finds no correlation between flood magnitudes and atmospheric carbon dioxide (CO2) concentrations in any region of the continental U.S. over the past 85 years.

More importantly, despite long-term increases in both CO2 concentrations and global temperatures since the 1920s, global deaths and death rates related to extreme weather declined by 93% and 98% respectively. The 93% reduction in annual weather-related deaths is particularly noteworthy because global population increased more than 300% since the 1920s.

Although weather-related damages are much bigger today, that is because there’s tons more stuff and lots more people in harm’s way. For example, more people live in just two Florida counties, Dade and Broward, than lived in all 109 coastal counties stretching from Texas to Virginia in the 1930s. When weather-related damages are adjusted (“normalized”) to account for changes in population, wealth, and inflation, there is no long-term trend. So although a “greenhouse signal” may some day emerge from weather-related mortality and economic loss data, at this point global warming’s influence, if any, is undetectable.

Sen. Whitehouse dismisses as a “gimmick” skeptics’ observation that there has been “no warming trend in the last ten years” (actually, the last 16 years).  He contends that the 20 warmest years in the instrumental record have occurred since 1981 ”with all 10 of the warmest years occurring in the past 12 years.” That may be correct, but it is beside the point. A decade and a half of no net warming continues the plodding 0.14°C per decade warming trend of the past 33 years. These data call into question the climate sensitivity assumptions underpinning the big scary warming projections popularized by NASA scientist James Hansen, the UN IPCC, and the UK Government’s Stern Review report.

Sen. Whitehouse says ”deniers tend to ignore facts they can’t explain away.” He continues: “For example, the increasing acidification of the oceans is simple to measure and undeniably, chemically linked to carbon concentrations in the atmosphere. So we hear nothing about ocean acidification from the deniers.” Not so. CO2Science.Org, a leading skeptical Web site, has an extensive (and growing) ocean acidification database. Almost every week the CO2Science folks review another study on the subject. Cato Institute scholars Patrick Michaels and Chip Knappenberger also addressed the issue on their old Web site, World Climate Report. They don’t share Sen. Whitehouse’s alarm about ocean acidification, but they do not ignore it. The Senator should check his facts before casting aspersions.

Sen. Whitehouse quotes NOAA stating that the rate of global sea level rise in the last decade “was nearly double” the 20th century rate. That is debatable. Colorado State University researchers find no warming-related acceleration in sea-level rise in recent decades.

Here’s the big picture. Scary projections of rapid sea-level rise assume rapid increases in ice loss from Greenland. In a study just published in Proceedings of the National Academy of Sciences, scientists used satellite gravity data to measure changes in Greenland’s ice mass balance from April 2002 to August 2011. The researchers estimate Greenland is losing almost 200 gigatons of ice per year. It takes 300 gigatons of water to raise sea levels by 1 millimeter, so Greenland is currently contributing about 0.66 mm of sea-level rise per year. At that rate, Greenland will contribute 6.6 centimeters of sea level rise over the 21st century, or less than 3 inches. Apocalypse not.

Sen. Whitehouse concludes by castigating Republicans for inveighing against unchecked entitlement spending and the fiscal burdens it imposes on “our children and grandchildren” while turning a blind eye to the perils climate change inflicts on future generations. But such behavior is not contradictory if the risk of fiscal chaos is both (a) more real and imminent than Al Gore’s “planetary emergency” and (b) more fixable within the policy-relevant future.

Here are two facts Sen. Whitehouse should contemplate. First, even if the U.S. were to stop emitting all CO2 tomorrow, the impact on global temperatures would be a reduction of “approximately 0.08°C by the year 2050 and 0.17°C by the year 2100 — amounts that are, for all intents and purposes, negligible,” notes Chip Knappenberger, whose calculations are based on IPCC climate sensitivity assumptions. Similarly, a study in Nature Climate Change concludes that aggressive climate change ”mitigation measures, even an abrupt switch to zero emissions, have practically no effect on sea level over the coming 50 years and only a moderate effect on sea level by 2100.”

Whether under a carbon tax, cap-and-trade, or EPA regulation, the U.S. would keep emitting billions of tons of CO2 annually for a long time. So whatever climate policies Sen. Whitehouse thinks Republicans should support would have no discernible impact on climate change risk. The costs of such policies would vastly exceed the benefits. Rejecting policies that are all pain for no gain is exactly what the custodians of America’s economic future are supposed to do.

With Senators Barbara Boxer (D-Calif.) and Frank Lautenberg (D-N.J.) citing Hurricane Sandy as a reason to have another go at climate legislation, to say nothing of the media spin depicting Sandy as punishment for our fuelish ways, it’s useful to look at some actual science.

In a study published in the journal Climatic Change, scientists Michael Chenoweth and Dmitry Divine analyze the history of tropical cyclone activity in the Lesser Antilles from 1638 to 2009. The Lesser Antilles are the string of islands lying along the eastern Caribbean Sea.

The Lesser Antilles intersect the “main development region” for Atlantic hurricane formation, making storm data there “our best source for historical variability of tropical cyclones in the tropical Atlantic in the past three centuries,” the researchers explain.

Using instrumental data on wind speeds going back to 1900 plus wind-force and wind-induced damage reports for earlier periods, Chenoweth and Divine estimate the Lesser Antilles Accumulated Cyclone Energy (LACE) for each year along the 61.5°W meridian from 18 to 25° N latitude.

Storms forming in this area include most that do or could make landfall in the U.S. In the researchers’ words: “About 60% of all tropical cyclones moving from waters off of Africa pass through 61.5°W south of 25.0°N, the remaining 40% either moving north of 25.0°N, dying out or re-curving to the east of 61.5°W.” Chenoweth and Divine note that LACE is “highly correlated” with Carribbean basin-wide Accumulated Cyclone Energy (ACE) since 1899.

So what did they find? In their words: “Our record of tropical cyclone activity reveals no trends in LACE in the best-sampled regions for the past 320 years. Likewise, even in the incompletely sampled region north of the Lesser Antilles there is no trend in either numbers or LACE.”

Chenoweth and Divine do find a “~50–70 year variability in ACE across the 18–25°N transect.” This wave-like pattern ”is possibly associated with the low-frequency variations in the Atlantic Multi-Decadal Oscillation (AMO), a mode of SST [sea surface temperature] variability that is global in extent but strongest in the Atlantic.” The scientists consider their data “sufficiently complete to be a reliable record back to 1785 and extends the evidence of this pattern further back in time.”

An obvious implication of the study, although not spelled out by the authors, is that natural variability dominates tropical storm activity in the Atlantic to the point that any global warming influence, if it exists, is still undetectable.

For a more detailed review of the study, visit the Center for the Study of Carbon Dioxide and Global Change. Also informative is World Climate Report’s review of Chenoweth and Divine’s 2008 study on tropical cyclones in the Lesser Antilles.

That’s what the self-anointed ‘consensus of scientists’ claims. As noted in a previous post this week, right after the IPCC famously declared that the 1990s were likely the warmest decade of the past millennium, they stated: “Evidence does not support the existence of globally synchronous periods of cooling or warming associated with the ‘Little Ice Age’ and ‘Medieval Warm Period’” (Third Assessment Report, Chap. 2, p. 102).

But those remarkable Idsos, Shirwood, Craig, and Keith, keep reviewing studies that find evidence of the Medieval Warm Period (MWP) and Little Ice Age (LIA) not only in Europe but also in Asia, Africa, Australia/New Zealand, North America, South America, the Oceans, and even Antarctica. What’s more, the preponderance of these studies indicate that the MWP was warmer than the current warm period (CWP). The Idsos divide these studies into two categories, Level 1 Studies, which attempt to quantify the difference between MWP peak temperatures and CWP peak temperatures, and Level 2 Studies, which indicate whether the MWP peak temperatures were higher than, lower than, or the same as CWP peak temperatures.

This week on their Web site, CO2Science.Org, the Idsos review a study, published in Earth and Planetary Science Letters, that attempts to reconstruct the temperature history of the Antarctic Peninsula from ikaite crystals (an icy version of limestone) in marine sediments.  The study, by Zunli Lu of Syracuse University and colleagues, finds that “both the Medieval Warm Period and Little Ice Age extended to the Antarctic Peninsula.” What is more, the researchers find that the “climatic signature” from the most recent crystals is “not yet as extreme in nature as the MWP.”

Prof. Lu cautions that the study “does not question the well-established anthropogenic warming trend” of recent decades and that results from one site “should not be extrapolated to make assumptions about climate conditions across the entire globe.” Nonetheless, the Idsos reasonably conclude that the study is additional evidence that “the Earth has not yet eclipsed the level of global warmth experienced during the MWP.”

In 2001, the U.N. Intergovernmental Panel on Climate Change (IPCC) featured a graph of Northern Hemisphere temperature history from a 1999 study by Profs. Michael Mann, Raymond Bradley, and Malcolm Hughes. Because of its shape, the graph became known as the “hockey stick.” From A.D. 1,000 to about 1915, the graph depicts a gradual decline in Northern Hemisphere temperatures (the hockey stick handle) followed by an abrupt upturn in hemispheric temperatures during the remainder of the 20th century (the blade).

The graph appears in the IPCC 2001 report’s Summary for Policymakers, Technical Summary, and chapter 2 on Observed Climate Variability and Change. Based on the Mann-Bradley-Hughes (MBH) study, the IPCC famously concluded that, “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” (chapter 2, p. 102). The IPCC also asserted that, “Evidence does not support the existence of globally synchronous periods of cooling or warming associated with the ‘Little Ice Age’ and ‘Medieval Warm Period’.” The hockey stick instantly became the poster child for pro-Kyoto advocacy, touted as seeing-is-believing evidence that late 20th century warmth was unprecedented during the past 1,000 years, and that mankind’s fuelish ways must be to blame.

Soon after its PR boost from the IPCC, the hockey stick became embroiled in a controversy that persists to this day. Books both pro and con have been written on the subject. Two leading critics, mining consultant Steve McIntyre and economist Ross McKitrick, argued that MBH’s computer program generates hockey stick-shaped graphs from random data. As for the IPCC’s dismissal of the Medieval Warm Period as a European phenomenon, the Center for the Study of Carbon Dioxide and Global Change maintains a large and growing archive of studies indicating that the Medieval Warm Period was global and/or warmer than recent decades.

A recent study published in Nature Climate Change further undermines the credibility of the hockey stick. The study, “Orbital forcing of tree-ring data,” by Jan Esper of Johannes Gutenberg University, in Germany, and colleagues from Germany, Switzerland, Finland, and Scotland, used X rays to measure changes in the cell-wall density of trees in Northern Finland over the past 2,000 years. The analysis examined both “living and subfossil pine (Pinus sylvestris) trees from 14 lakes and 3 lakeshore sites.”

The researchers argue that “X-ray densitometry” enables a more accurate reconstruction of climate history than does analyzing the width of tree rings – the principal data used by MBH. For example, MBH found a “divergence,” starting in 1960, between a decline in Northern Hemisphere temperatures, as reconstructed from tree ring data, and the increase in Northern Hemisphere temperatures, as measured by thermometers and other heat sensing instruments. The divergence raises the question of how MBH can be so sure the Medieval Warm Period was tiny or non-existent when their proxy data fail to reflect the instrument-measured warmth of recent decades. To give the hockey stick its dangerous-looking blade, MBH had to “hide the decline.”

In contrast, the Esper team found no divergence between instrumental data and temperatures inferred from density analysis of living trees in the study area.

So what’s the upshot? Their reconstruction “shows a succession of warm and cold episodes including peak warmth during Roman and Medieval times alternating with severe cool conditions centred in the fourth and fourteenth centuries.”  The warmest 30-year period was A.D. 21-50, which was 1.05°C warmer than the mean temperature for 1951-1980 and ~0.5°C warmer than the region’s maximum 20th century warmth, which occured during 1921-1950.

Source: Esper et al. 2012 (extracted by CO2.Science.Org)

The reconstruction also “reveals a long-term cooling trend of -0.31°C per 1,000 years (±0:03°C) over the 138 B.C.-A.D. 1900 period . . .” This trend is not reflected in tree ring width data from “the same temperature-sensitive trees.” Thus, reliance on such data (as in the hockey stick reconstruction) ”probably causes an underestimation of historic temperatures.”

The authors write in a politic manner. Although they reference the MBH study, they do not directly criticize it or mention the hockey stick by name. They do not claim their reconstruction is definitive. However, they do argue that the reconstruction reflects long-term changes in ”orbital configurations” that have continually reduced Northern Hemisphere summer “insolation” (solar irradiance) over the past two millennia. If so, then we should expect densitometry analysis of trees in other parts of the Northern Hemisphere to produce similar results.

Climate alarm skeptics will be pleased to see in the chart above evidence that the Roman Warm Period and Medieval Warm Period were warmer than the late 20th century. On the other hand, they may not be pleased by an apparent implication of the study. If Northern Hemisphere temperatures have been in an overall cooling trend for two millennia due to ”orbital forcing” (i.e. reduced solar irradiance), then the burden of proof becomes greater on those who attribute the warmth of recent decades to solar variability rather than rising greenhouse gas concentrations.

Did the Medieval Warm Period (MWP) and Little Ice Age (LIA) occur only in Europe, or were they global in scope?

This is a hotly debated question, because it is harder to make the case that the warmth of recent decades is “unusual,” ”extraordinary,” or “unprecedented” and therefore something to stress about if global climate oscillates naturally between warming and cooling periods. The catastrophic anthropogenic global warming (CAGW) crowd tend to write off the MWP (~1000-1200 A.D.) and LIA (~1300-1850 A.D.) as regional phenomena, largely confined to Northern Europe. A new study finds evidence of the MWP and LIA in a region 10,000 miles south of Northern Europe: the Antarctic Peninsula.

WattsUpWithThat provides a lengthy excerpt from the new study, ”An ikaite record of late Holocene climate at the Antarctic Peninsula,” which will be published in Earth and Planetary Science Letters.  A Syracuse University press release summarizes the study’s methodology and findings:

 A team of scientists led by Syracuse University geochemist Zunli Lu has found a new key [to climate history] in the form of ikaite, a rare mineral that forms in cold waters. Composed of calcium carbonate and water, ikaite crystals can be found off the coasts of Antarctica and Greenland.

“Ikaite is an icy version of limestone,” say Lu, assistant professor of earth sciences in SU’s College of Arts and Sciences. “The crystals are only stable under cold conditions and actually melt at room temperature.”

It turns out the water that holds the crystal structure together (called the hydration water) traps information about temperatures present when the crystals formed. This finding by Lu’s research team establishes, for the first time, ikaite as a reliable proxy for studying past climate conditions.

* * *

The scientists were particularly interested in crystals found in layers deposited during the “Little Ice Age,” approximately 300 to 500 years ago, and during the “Medieval Warm Period,” approximately 500 to 1,000 years ago. Both climate events have been documented in Northern Europe, but studies have been inconclusive as to whether the conditions in Northern Europe extended to Antarctica.

Ikaite crystals incorporate ocean bottom water into their structure as they form. During cooling periods, when ice sheets are expanding, ocean bottom water accumulates heavy oxygen isotopes (oxygen 18). When glaciers melt, fresh water, enriched in light oxygen isotopes (oxygen 16), mixes with the bottom water. The scientists analyzed the ratio of the oxygen isotopes in the hydration water and in the calcium carbonate. They compared the results with climate conditions established in Northern Europe across a 2,000-year time frame. They found a direct correlation between the rise and fall of oxygen 18 in the crystals and the documented warming and cooling periods.

Although the authors do not claim to have “unambiguously established” the MWP in the Antarctic Peninsula (AP), they conclude that their “ikaite record builds the case that the oscillations of the MWP and LIA are global in their extent and their impact reaches as far South as the Antarctic Peninsula, while prior studies in the AP region have had mixed results.” Their research also indicates that the AP may have been warmer during the MWP than in recent decades: ”Our most recent crystals suggest a warming relative to the LIA in the last century, possibly as part of the regional recent rapid warming, but this climatic signature is not yet as extreme in nature as the MWP” (emphasis added).

Although the Lu team is the first to use akaite as a proxy, they are far from the first to find evidence of the MWP outside of Europe. The Medieval Warm Period Project of the Center for the Study of Carbon Dioxide and Global Change reviews (by my count) 20 studies in Africa, 8 in Antarctica, 68 in Asia, 6 in Australia/New Zealand, 92 in North America, 31 in various Ocean areas, and 19 in South America, in addition to 97 in Europe – all indicating a period of climatic warmth approximately one thousand years ago. Many of those studies indicate that the MWP was warmer than the Current Warm Period (see the chart at the top of this post).

No — or, more precisely, not  yet — conclude R.M. Hirsch and K.R. Ryberg of the U.S. Geological Survey in a recent study published in Hydrological Sciences Journal.

“One of the anticipated hydrological impacts of increases in greenhouse gas concentrations in the atmosphere is an increase in the magnitude of floods,” note Hirsch and Ryberg. Righto! Google “global warming” and “flood predictions,” and you’ll find more than 2.7 million sites where this hypothesis is affirmed or at least discussed. The researchers explain:

Greenhouse gases change the energy balance of the atmosphere and lead to atmospheric warming, which increases the water-holding capacity of the atmosphere, which in turn, potentially changes the amount of precipitable water.

Sounds plausible, but all weather is local or regional, and a lot more goes into making weather than average global temperature.  In addition, all flooding is local or regional, and a lot more goes into determining flood risk than local or regional weather patterns.

As Hirsch and Ryberg point out, “human influences associated with large numbers of very small impoundments and changes in land use also could play a role in changing flood magnitude,” and “at time scales on the order of a century it is difficult to make a quantitative assessment of the changes in these factors over time.”

That, however, did not stop good ol’ Al Gore from claiming that global warming is responsible for a decade-by-decade increase in the number of large floods around the world (An Inconvenient Truth, p. 106). Gore’s source was a chart from the Millennium Ecosystem Assessment (Figure 16.5, p. 448):

The chart does appear to show significant decadal increases in the number of floods. However, what the chart actually measures is the number of “damaging” floods, and whether or not a flood is classified as “damaging” is influenced by socio-economic and even political factors. As the MEA report explains:

Only events that are classified as disasters are reported in this database. (An event is classified as a disaster if it meets at least one of the following criteria: 10 or more people reported killed; 100 or more people reported affected; international assistance was called; or a state of emergency was declared . . .

Obviously, the database is going to be skewed towards more events in later decades simply because of better reporting, more declared states of emergency, and more calls for international assistance. As the MEA report observes, “although the number has been increasing, the actual reporting and recording of floods have also increased since 1940, due to the improvements in telecommunications and improved coverage of global information.”

The MEA report also identifies several non-climatic factors that influence flood damage risk: wetlands loss and deforestation, changes in engineering practices, irrigation, urbanization, and, perhaps most importantly, population growth and economic development in flood plains.

In short, teasing out a greenhouse warming “signal” from flood damages influenced by both natural climate variability and a host of societal factors is a daunting task. Yet Gore treats flood damage data as unambiguous evidence of a warming-ravaged planet.

Okay, let’s get back to the USGS scientists. Hirsch and Ryberg acknowledge they cannot entirely filter out “reservoir storage, urban development, or other human activities in the watersheds” without narrowing their study “almost entirely to very small watersheds, typically in remote and often mountainous areas.” As a reasonable compromise, they examined flood data from “200 streamgauges operated by the US Geological Survey (USGS) in the coterminous USA, of at least 85 years length through water year 2008, from basins with little or no reservoir storage or urban development (less than 150 persons per square kilometre in 2000).”

What did they find? From the paper’s abstract:

In none of the four regions [Northeast, Southeast, Northwest, Southwest] defined in this study is there strong statistical evidence for flood magnitudes increasing with increasing GMCO2 [global mean carbon dioxide concentration]. One region, the southwest, shows a statistically significant negative relationship between GMOC2 and flood magnitudes.

For further reading, the Center for the Study of Carbon Dioxide and Global Change summarizes the results of 21 peer-reviewed studies on flooding and climate variability in North America. The Center concludes:

Taken together, the research described in this Summary suggests that, if anything, North American flooding tends to become both less frequent and less severe when the planet warms, although there have been some exceptions to this general rule.  Hence, although there could also be exceptions to this rule in the case of future warming, on average, we would expect that any further warming of the globe would tend to further reduce both the frequency and severity of flooding in North America, which, of course, is just the opposite of what the world’s climate alarmists continue to claim would occur.

It’s a trick employed by rhetoricians from time immemorial. When their case against an opponent is unpersuasive on the merits, they invoke the image of something their target audience fears or hates. Thus, for example, political pleaders have asserted that money, Dick Cheney, or Zionism ”is a cancer on the body politic.”

Perhaps the most influential use of this tactic in modern times is the attack on carbon dioxide (CO2) as “global warming pollution” and on CO2 emitters as “polluters.” Many who know better, including highly credentialed scientists, routinely couple the words “carbon” and “pollution” in their public discourse.

In reality, CO2 — like water vapor, the atmosphere’s main greenhouse gas — is a natural constituent of clean air. Colorless, odorless, and non-toxic to humans at 30 times ambient concentrations, CO2 is an essential building block of the planetary food chain. The increase in the air’s CO2 content since the dawn of the industrial revolution — from 280 to 390 parts per million – boosts the water-use efficiency of trees, crops, and other plants; helps protect green things from the damaging effects of smog and UV-B radiation; and helps make food more plentiful and nutritious. The many health and welfare benefits of atmospheric CO2 enrichment make CO2 unlike any other substance ever previously regulated as a “pollutant.”

A closely related abuse of the English languge is the oft-repeated claim that America is “addicted to oil.” Although popularized by a Texas oil man, former President G.W. Bush, the phrase is a rhetorical staple of the same folks who inveigh against “carbon pollution.” NASA scientist James Hansen, arguably the world’s most famous carbonophobe besides Al Gore, recently denounced the Keystone XL Pipeline as a “dirty needle” that, if approved, would feed our supposed oil addiction.

President Obama is expected later this year to approve or deny a permit allowing construction of the proposed 1,700 mile pipeline that would bring oil from Canada’s vast tar sands reserves to U.S. refineries in the Midwest and Gulf Coast. As reported in The New York Times, Hansen said that Obama has a rare opportunity, by denying the permit, to show that he is not a “hopeless addict.”

“If Obama chooses the dirty needle it will confirm that Obama was just greenwashing all along, like the other well-oiled coal-fired politicians, with no real intention of solving the addiction,” Hansen said.

Why does anyone listen to Hansen? Because he’s a highly credentialed scientist. But when he says stuff like this, he is only pretending to speak as a scientist. He is actually speaking as a political advocate, and with scant regard for facts or reason.

America is no more addicted to oil than our ancestors were to horse fodder. We use oil, as they used fodder, to get us where we want to go. What consumers care about is not the oil or the fodder, but the mobility it provides and the associated costs. Yes, those costs include environmental impacts. But, mile for mile, a horse is a far more polluting ‘technology’ than an automobile. As soon as an alternative fuel comes along that delivers more bang for our transportation buck than gasoline does, Americans will demand it, and competition will drive profit-seeking firms to supply it.

Yes, we depend on oil to fuel most of our cars, marine vessels, and aircraft. But dependence is not addiction. We also depend on electricity to power our lap tops, iPods, and cell phones, and we depend on food and water to sustain life. No sane person would say we are addicted to those things.

One quality of a typical addiction is that it is an appetite that grows with feeding. Nationally, our long-term oil consumption is growing. But that’s  due to population growth, which increases the number of motorists, and economic growth, which increases the supply of goods to be moved and expands opportunities to travel for business, education, and recreation. The long-term increase in “vehicle miles traveled” is not the result of some narcotic-like effect that gasoline consumption induces in motorists. It is a consequence of healthy development — more abundant life and more economic activity.

As my colleague Myron Ebell once said, nobody in America wakes in a cold sweat, sneaks out of the house late at night, and pays a road side pusher top off the tank with regular unleaded.