Nina Teicholz on the Last Anti-Fat Crusaders

Nina Teicholz, The Last Anti-Fat Crusaders, The Wall Street Journal, October, 28, 2014

The low-fat-diet regimen is turning out to be based on bad science, but the USDA has been slow to catch on.  

The top scientist guiding the U.S. government’s nutrition recommendations made an admission last month that would surprise most Americans. Low-fat diets, Alice Lichtenstein said, are “probably not a good idea.” It was a rare public acknowledgment conceding the failure of the basic principle behind 35 years of official American nutrition advice.

Yet the experts now designing the next set of dietary recommendations remain mired in the same anti-fat bias and soft science that brought us the low-fat diet in the first place. This is causing them to ignore a large body of rigorous scientific evidence that represents our best hope in fighting the epidemics of obesity, diabetes and heart disease.

The Dietary Guidelines for Americans—jointly published by the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS) every five years—have had a profound influence on the foods Americans produce and consume. Since 1980, they have urged us to cut back on fat, especially the saturated kind found mainly in animal foods such as red meat, butter and cheese. Instead, Americans were told that 60% of their calories should come from carbohydrate-rich foods like pasta, bread, fruit and potatoes. And on the whole, we have dutifully complied.

By the turn of the millennium, however, clinical trials funded by the National Institutes of Health (NIH) were showing that a low-fat regime neither improved our health nor slimmed our waistlines. Consequently, in 2000 the Dietary Guidelines committee started to tiptoe away from the low-fat diet, and by 2010 its members had backed off any mention of limits on total fat.

Yet most Americans are still actively trying to avoid fat, according to a recent Gallup poll. They are not aware of the USDA’s crucial about-face because the agency hasn’t publicized the changes. Perhaps it did not want to be held responsible for the consequences of a quarter-century of misguided advice, especially since many experts now believe the increase in carbohydrates that authorities recommended has contributed to our obesity and diabetes epidemics.

Such a humbling reversal should have led the expert committee preparing the 2015 Dietary Guidelines, which holds its next-to-last public meeting Nov. 6-7, to fundamentally rethink the anti-fat dogma. But instead it has focused its anti-fat ire exclusively on saturated fats. Recent guidelines have steadily ratcheted down the allowable amount of these fats in the diet to 7% of calories “or less,” which is the lowest level the government has ever advised—and one that has rarely, if ever, been documented in healthy human populations.

The most current and rigorous science on saturated fat is moving in the opposite direction from the USDA committee. A landmark meta-analysis of all the available evidence, conducted this year by scientists at Cambridge and Harvard, among others, and published in the Annals of Internal Medicine, concluded that saturated fats could not, after all, be said to cause heart disease. While saturated fats moderately raise “bad” LDL-cholesterol, this does not apparently lead to adverse health outcomes such as heart attacks and death. Another meta-analysis, published in the respected American Journal of Clinical Nutrition in 2010, came to the same conclusion. The USDA committee has ignored these findings.

No doubt, accepting them would be another embarrassing reversal for nutrition experts. The USDA, the NIH and the American Heart Association have spent billions trying to prove and promote the idea that saturated fats cause heart disease.

In place of saturated fats, these agencies have counseled Americans to consume ever-larger quantities of unsaturated fats, which are found mainly in soybean and other vegetable oils. Yet a diet high in these oils has been found in clinical trials to lead to worrisome health effects, including higher rates of cancer. And the USDA, which espouses a commitment to finding healthy “dietary patterns” based in history, is now in the paradoxical position of telling Americans to derive most of their fats from these highly processed vegetable oils with virtually no record of consumption in the human diet before 1900.

The most hopeful path lies in a different direction: An enormous trove of research over the past decade has shown that a low-carbohydrate regime consistently outperforms any other diet in improving health. Diabetics, for instance, can most effectively stabilize their blood glucose on a low-carb diet; heart-disease victims are able to raise their “good” HDL cholesterol while lowering their triglycerides. And at least two-dozen well-controlled diet trials, involving thousands of subjects, have shown that limiting carbohydrates leads to greater weight loss than does cutting fat.

The USDA committee’s mandate is to “review the scientific and medical knowledge current at the time.” But despite nine full days of meetings this year, it has yet to meaningfully reckon with any of these studies—which arguably constitute the most promising body of scientific literature on diet and disease in 50 years. Instead, the committee is focusing on new reasons to condemn red meat, such as how its production damages the environment. However, this is a separate scientific question that is outside the USDA’s mandate on health.

Rates of obesity in the U.S. started climbing dramatically right around 1980, the very year in which the Dietary Guidelines were first introduced. More than three decades later, more of the same advice can only be expected to produce similarly dismal health outcomes. And the cost, in human and dollar terms, will continue to be catastrophic.

These are compelling reasons for Congress to ask the USDA and HHS to reconstitute the Dietary Guidelines committee so that its members represent the full range of expert opinion. The committee should then be mandated to fundamentally reassess the Guidelines’ basic assumptions, based on the best and most current science. These measures would give millions of Americans a fighting chance in their battle against obesity, diabetes and heart disease—and at last start to reverse the ill effects of our misguided Dietary Guidelines.

Ms. Teicholz is the author of “The Big Fat Surprise: Why Butter, Meat, and Cheese Belong in a Healthy Diet” (Simon & Schuster, 2014).

Aly Salem on How Islam Has Been Hijacked

Aly Salem, "Let’s Talk About How Islam Has Been Hijacked," The Wall Street Journal, August 26, 2014

I’m appalled by what is done in the name of my religion. Yet my American friends don’t want to hear it.

This week a Canadian Muslim gunman went on a rampage in Ottawa, killing a soldier and storming into the Parliament building before he was shot dead. Authorities have since said he had applied for a passport to travel to Syria. Three Muslim schoolgirls from Colorado were intercepted in Germany apparently on their way to Syria, the base for attacks there and in Iraq by the terror group Islamic State, or ISIS. An Aug. 20 article in Newsweek estimated that perhaps twice as many British Muslims are fighting for ISIS as are serving in the British army.

What could possibly inspire young Muslims in the West to abandon their suburban middle-class existence and join a holy war? How could teenagers in Denver or anywhere be lured by a jihadist ideology—or are grisly videos of ISIS beheadings and crucifixions not enough of a deterrent?

What is so compelling about radical Islamism may lie within its founding texts. It is time we acknowledged the powerful influence these texts have had even on ordinary Muslims. The political ideology based on them has already dragged the Middle East back toward the Stone Age.

As a teenager growing up in Egypt in the 1980s, I liked to stroll through Cairo’s outdoor book market, fishing out little gems like an Arabic translation of “War and Peace.” One day I stumbled upon a book that shook everything I believed in.

The book was “In the Shadows of the Quran,” Sayyed Qutb’s magnum opus. The Egyptian writer, who died in 1966, remains arguably the most influential thinker in contemporary Muslim societies. He was the principal theorist of the Muslim Brotherhood and the intellectual impetus behind the Islamist parties it spawned. Qutb’s ardent disciples included Osama bin Laden and Ayman Zawahiri of al Qaeda. It is not an exaggeration to say that Qutb is to Islamism what Karl Marx is to communism.

Qutb’s brilliance as a theorist was in how he applied Western-style literary criticism to the Quran to interpret God’s intentions. He concluded that the reason for the Muslim world’s decline were external cultural and political influences that diluted Islam: The culprits included everything from Greek empiricism and liberal democracy to socialism, Persian poetry and Hegelian philosophy. The only path to an Islamic renaissance was to cleanse Muslim societies of these contaminants and restore Islam to its seventh-century purity.

Today, Qutb’s outlook—Islamism—is the dominant political ideology in most Muslim-majority countries, often taking root in vacuums where secular politics have never had space to develop. Polls by the Pew Research Center, such as 2013’s “The World’s Muslims” indicate that in many Muslim countries, the population is overwhelmingly in favor of veiling for women, the death penalty for leaving Islam and stoning as punishment for adultery; rabid anti-Semitism is rampant. The few exceptions to these statistics tend to be countries with a long history of militant secularism (like Turkey), or former communist states (Tajikistan, Bosnia, Albania, etc.) where religion was effectively wiped out of the public sphere. But Islamism is now growing even in those places.

The trend of history is being reversed. In Egypt, for instance, veiling was unheard of 50 years ago and was virtually extinct until the Islamists resurrected the practice in the 1970s. Today an estimated 90% of Egyptian women are veiled. In many other countries the veil—originally a tribal norm not a religious one—is now ubiquitous, as are views on apostasy in countries that were far more progressive 50 years ago.

Many of my fellow Muslims are trying to reform Islam from within. Yet our voices are smothered in the West by Islamist apologists and their well-meaning but unwitting allies on the left. For instance, if you try to draw attention to the stark correlation between the rise of Islamic religiosity and regressive attitudes toward women, you’re labeled an Islamophobe.

In America, other contemporary ideologies are routinely and openly debated in classrooms, newspapers, on talk shows and in living rooms. But Americans make an exception for Islamism. Criticism of the religion—even in abstraction—is conflated with bigotry toward Muslims. There is no public discourse, much less an ideological response, to Islamism, in academia or on Capitol Hill. This trend is creating an intellectual vacuum, where poisonous ideas are allowed to propagate unchecked.

My own experience as a Muslim in New York bears this out. Socially progressive, self-proclaimed liberals, who would denounce even the slightest injustice committed against women or minorities in America, are appalled when I express a similar criticism about my own community.

Compare the collective response after each harrowing high-school shooting in America. Intellectuals and public figures look for the root cause of the violence and ask: Why? Yet when I ask why after every terrorist attack, the disapproval I get from my non-Muslim peers is visceral: The majority of Muslims are not violent, they insist, the jihadists are a minority who don’t represent Islam, and I am fear-mongering by even wondering aloud.

This is delusional thinking. Even as the world witnesses the barbarity of beheadings, habitual stoning and severe subjugation of women and minorities in the Muslim world, politicians and academics lecture that Islam is a “religion of peace.” Meanwhile, Saudi Arabia routinely beheads women for sorcery and witchcraft.

In the U.S., we Muslims are handled like exotic flowers that will crumble if our faith is criticized—even if we do it ourselves. Meanwhile, Republicans and Democrats alike would apparently prefer to drop bombs in Syria, Iraq, Afghanistan and beyond, because killing Muslims is somehow less offensive than criticizing their religion? Unfortunately, you can’t kill an idea with a bomb, and so Islamism will continue to propagate. Muslims must tolerate civilized public debate of the texts and scripture that inform Islamism. To demand any less of us is to engage in the soft bigotry of low expectations.

Mr. Salem is an Egyptian writer based in New York.

Glennon and Libecap on Water Markets

Robert Glennon and Gary Libecap, "The West Needs a Water Market to Fight Drought," The Wall Street Journal, October 4, 2014

Outdated laws are wasting the region’s scarcest resource. Water should be tradable so it finds its most urgent uses.

The drought in the Western U.S. from California to Texas has generated gloomy editorials and op-eds predicting dire consequences and even water wars. But the West is not running out of water, nor are prolonged fights over water inevitable. Modest changes in water use could have big results: A reduction of just 4% in agricultural consumption would increase the water available for residential, commercial and industrial uses by roughly 50%, according to our analysis of U.S. Geological Survey data.

Yet even after the current drought ends, the West will continue to suffer water shortages thanks to population growth, economic development and the effects of climate change. When engineers designed the water infrastructure in arid states in the West, they assumed that future droughts and floods would follow historical patterns. But precipitation patterns have changed.

Traditional solutions—diverting more water from rivers, building new reservoirs or drilling additional groundwater wells—are no longer ways to substantially increase the water supply. In a new report for The Hamilton Project at the Brookings Institution, we, along with co-author Peter W. Culp, propose that states use market tools to promote water trading. That is, farmers or other users who reduce their consumption should be allowed to lease or sell the conserved water.

A major overhaul of Western water law is overdue, but implementing such reform would take years. In the near term, states should authorize short-term leases of water, build basic market institutions, deploy risk-mitigation tools such as dry-year options, and implement basic controls such as regulating how much water can be pumped. The current absence of viable market opportunities and incentives is producing perverse results.

In 2014 the worst drought in memory caused California farmers to fallow almost 500,000 acres of land, including some that produced high-value fruit and nut trees. Meanwhile, Western growers of alfalfa—a low-value and high-water-use crop—are on pace this year to export two million tons of alfalfa to China, South Korea and Japan—produced with enough water to supply several million U.S. families for a year or to irrigate hundreds of thousands of acres of high-value almond trees. If there were ways to trade water, some farmers could cut back on the production of more water-intensive, lower-value crops and lease or sell the conserved water to desperate fruit and nut growers or thirsty cities.

Most farmers don’t have that option. Even though federal and state policy fosters the export of agricultural commodities, Western water law generally inhibits trade in the water used to grow the commodities. States should open up the market by eliminating or streamlining legal barriers that effectively block transfers of water.

A market in water would encourage efficiency by stimulating innovation, promoting specialization and allowing water to move from lower-value to higher-value uses. Farmers who have an opportunity to trade a portion of their water have an incentive to take measures, such as installing more efficient irrigation systems, to free up water for trade. It would also create opportunities to deploy market-based tools, such as dry-year options, to help mitigate water risks to farms and cities.

For example, under a dry-year option, a water user with a low tolerance for water shortages—such as an almond farmer whose trees would quickly die without water—can contract with a seasonal agricultural user, such as a broccoli grower. In dry years, the almond producer would have the right to use the broccoli grower’s water. The almond producer pays a yearly premium to guard against times when water shortages would result in the loss of his orchard. The proceeds from the option give the broccoli grower a guaranteed revenue stream and thereby provide a hedge against a drought that might destroy his annual crop—mitigating risk for both parties.

The U.S. has a national interest in encouraging more efficient use of water everywhere. While Americans used to fret about running out of oil, water also fuels the American economy. A 2013 survey of the world’s largest companies by Deloitte Consulting found that 70% of respondents identified water as a substantial business risk, either in direct operations or supply chains. Companies with water challenges include obvious ones, such as Coca-Cola , and surprising ones, such as Intel , which needs large quantities of water to produce its processors.

The Western water crisis is basically an imbalance between supply and demand. Opening water resources to trade has the potential to reduce the imbalance by rewarding water conservation, ensuring that water goes toward the highest-value and most-efficient uses, and providing the financial tools to mitigate fluctuations in water availability.

Mr. Glennon, a law professor at the University of Arizona, is the author, most recently, of “Unquenchable: America’s Water Crisis and What to Do about It” (Island Press, 2009). Mr. Libecap, a professor at the University of California at Santa Barbara’s Bren School of Environmental Science and Management, is co-author of “Environmental Markets: A Property Rights Approach” (Cambridge University Press, 2014).

 

Pricing Water

http://www.nytimes.com/2014/10/15/business/economy/the-price-of-water-is-too-low.html?_r=0

Stephens on America's Disastrous Foreign Policy

Bret Stephens, "Obama Survival Manual, Int. Edition," The Wall Street Journal, October 14, 2014

If you think 2014 has been a year of unraveling and disorder, just wait.

So Paul Krugman, who once called on Alan Greenspan “to create a housing bubble to replace the Nasdaq bubble”; who, a few months before the eurozone crisis erupted, praised Europe as “an economic success” that “shows that social democracy works”; who, as the U.S. fracking revolution was getting under way, opined that America was “just a bystander” in a global energy story defined by “peak oil”; and who, in 2012, hailed Argentina’s economy as a “remarkable success story”—this guy now tells us, in Rolling Stone magazine, that Barack Obama has been a terrific president.

Which can only mean that the next two years are going to be exceptionally ugly. How to get through them?

***

I ask the question not as an exhortation to subscribe to Survivalist magazine, stock up on tuna fish and Zithromax, and master the arts of homolactic fermentation. In fact, if you’re a resident of the U.S., you’ll probably be OK. What Americans call a recession is what the rest of the world considers affluence. What we call disaster is what others know as existence.

But imagine if you are one of the pro-democracy student leaders in Hong Kong; or the president of Estonia or another country in Vladimir Putin ’s sights; or an anti-ISIS Sunni tribal sheik in Iraq; or a commander in the Kurdish Peshmerga; or a fighter in what remains of the Free Syrian Army; or the new president of Afghanistan; or the prime minister of Israel: What are you going to do then? How do you navigate a world in which you can no longer expect the U.S. to serve as a faithful ally and reliable buffer between you and your enemies?

Don’t think those questions aren’t on foreign minds. The other day, Mikhail Khodorkovsky, the Russian oil oligarch turned political prisoner turned (since his release earlier this year) democracy activist, paid a visit to the Journal’s offices in New York. We asked him how Vladimir Putin would react if the U.S. were to arm the Ukrainians or send forces to the Baltics.

“In Russia,” he replied, “everyone understands that America is not ready to fight. End of discussion.”

Or here’s what Vlad Filat, the pro-American former prime minister of Moldova—on which Russia has clear territorial designs—told me a few months ago. “Right now, Russia is fighting two wars, an energy war and an information war. Nobody is fighting back.”

Or here’s what Saudi Prince al-Waleed bin Talal told us last November. “The U.S. has to have a foreign policy. Well defined, well structured. You don’t have it right now, unfortunately. It’s just complete chaos.”

Each comment makes the same essential point: Don’t fear America, don’t trust America, don’t wait for American rescue. A corollary point, surely not lost on Mr. Putin, Ayatollah Khamenei and other rogues is that they have a free hand at least until January 2017. The conclusion: If ever there was a time to revise their regional orders in ways more to their liking, better to do so now, when there’s a self-infatuated weakling in the White House.

As for those on whom the rogues are likely to prey, there are two choices. One is to fight, as Ukraine bravely attempted to do in Donetsk and Luhansk earlier this year. The other is to seek whatever terms their adversaries are willing to offer, as Ukrainian President Petro Poroshenko now finds he has no choice but to do after Russia openly invaded his country and the U.S. refused to supply him with arms.

Afghanistan’s new president, the capable and decent Ashraf Ghani, will soon find himself facing a similar invidious choice with the Taliban and its backers in Islamabad as Mr. Obama completes the U.S. withdrawal by the end of 2016. In those circumstances it will not be unreasonable for Mr. Ghani to look for succor in Tehran, just as Baghdad has done, thereby giving Iran the opportunity to gain clients both to its east and west.

Nature abhors a vacuum, and so does power: American retreat means someone else—someone we don’t like—is going to step in.

Meanwhile, not all of our allies will capitulate so readily. Do not expect the Saudis to sit still if Iran and the West sign a nuclear deal that only John Kerry thinks is credible. Do not expect Japan to stick indefinitely to its nonnuclear pledges as cuts to the U.S. military increasingly hollow out the promise of the pivot, and as China becomes increasingly aggressive. Do not expect the Egyptians to resist the blandishments of potential strategic alliances with China or Russia as Washington holds Cairo at arms length.

This is a world of rambunctious rogues and fretful freelancers. If you think 2014 has been a year of unraveling and disorder, just wait till next year. In a time when the U.S. remains a bystander the wreckage can be immense.

Crovitz on creative Monopolies

L. Gordon Crovitz, "Three Cheers for ‘Creative Monopolies’," The Wall Street Journal, October 15, 2014

All Innovators have temporary market dominance. Peter Thiel knows this; so does Antonin Scalia. Too bad most lawyers and economists don’t.

 

Peter Thiel is larger than life even for a Silicon Valley billionaire. He co-founded PayPal, was the first investor in Facebook , and funded LinkedIn, Spotify, SpaceX and Airbnb. Now he has written a much-needed explanation of the information economy, masquerading as a breezy how-to book for entrepreneurs. “Zero to One: Notes on Startups, or How to Build the Future” is based on lectures Mr. Thiel gave at Stanford.

He hopes more entrepreneurs will focus on big ideas for health, energy and transportation; his venture firm’s tag line is “They promised us flying cars and all we got was 140 characters,” a reference to Twitter . His explanation of innovation is also a primer on how free markets work. He encourages entrepreneurs to ask: “What valuable company is nobody building?”

He warns against creating products that can be commoditized. “All happy companies are different: Each one earns a monopoly by solving a unique problem,” he writes. “All failed companies are the same: they failed to escape competition.” Example: Google , with its unique search advertising, is worth three times as much as all U.S. airlines combined.

Many reviewers are shocked by Mr. Thiel’s embrace of monopolies, but he is careful to defend only what he calls a “creative monopoly”—one that is “so good at what it does that no other firm can offer a close substitute.” In contrast with “illegal bullies or government favorites,” he observes, “creative monopolies give customers more choices by adding entirely new categories of abundance to the world.”

The Internet enables new creative monopolies. Companies can benefit from network effects, or what economists call demand-side economies of scale, to earn large market shares. PayPal became a favorite way to pay online once it achieved a critical mass of buyers and sellers. LinkedIn succeeded when enough people posted their work profiles to make the service valuable to employers and recruiters. Airbnb became attractive for homeowners to list residences as more people rented through the service.

Mr. Thiel’s contrarian claim that “monopoly is the condition of every successful business” echoes Joseph Schumpeter, the Austrian economist best known for coining “creative destruction.” Schumpeter explained in a 1942 book the key role of temporary monopolies in innovation: “The introduction of new methods of production and new commodities is hardly conceivable with perfect—and perfectly prompt—competition from the start. And this means that the bulk of what we call economic progress is incompatible with it. As a matter of fact, perfect competition is and always has been temporarily suspended whenever anything new is being introduced.”

Many academics and antitrust lawyers wrongly believe big is bad by definition. The Justice Department pursued IBM in the 1970s and Microsoft in the 1990s without understanding that in a dynamic market, where government doesn’t protect incumbents, new innovators displace old innovators. Apple undermined the dominance of Microsoft, which had ended IBM’s.

Mr. Thiel joins a long-running dispute. Justice Antonin Scalia set off a firestorm a decade ago when he defended monopolies in a majority opinion: “The mere possession of monopoly power, and the concomitant charging of monopoly prices, is not only not unlawful, it is an important element of the free-market system. The opportunity to charge monopoly prices—at least for a short period—is what attracts ‘business acumen’ in the first place; it induces risk taking that produces innovation and economic growth.”

That outraged Silicon Valley-based antitrust lawyer Gary Reback. In his book “Free the Market! Why Only Government Can Keep the Marketplace Competitive,” he called Justice Scalia’s ruling “unbelievable.” Mr. Reback asserted, “No one needs the prospect of a monopoly to induce investment.” That would be a losing argument at Mr. Thiel’s venture-capital firm.

Academic Tim Wu, who coined the pro-regulation term “net neutrality,” likewise demanded in his 2010 book “The Master Switch” that the government break up Google, Facebook and Apple as new monopolists. But all are creative monopolies. Better services, not law or regulation, give them their advantages in search advertising, display advertising and design.

Activists who want to break up creative monopolists don’t understand that only government can create the uncreative kind of monopoly, by protecting it from competition. AT&T enjoyed a government-granted monopoly for decades. Cities protected taxis from competition until Uber and Lyft gave choice to consumers.

Asked last week about springing Schumpeterian analysis on unsuspecting readers, Mr. Thiel laughed. “It wouldn’t be that bad for readers to get some Austrian economics on monopoly,” he told me. “Zero to One” wasn’t intended as a policy manifesto, but it should help return Silicon Valley to its roots favoring big innovation and small government.

De Soto on the Capitalist Cure for Terrorism

http://online.wsj.com/articles/the-capitalist-cure-for-terrorism-1412973796?mod=WSJ_hp_RightTopStories%20

Scruton on How to Be a Conservative

Notable and Quotable, The Wall Street Journal, October 9, 2014
From philosopher Roger Scruton’s new book “How to Be a Conservative”:
Conservatism starts from a sentiment that all mature people can readily share: the sentiment that good things are easily destroyed, but not easily created. This is especially true of the good things that come to us as collective assets: peace, freedom, law, civility, public spirit, the security of property and family life, in all of which we depend on the cooperation of others while having no means singlehandedly to obtain it. In respect of such things, the work of destruction is quick, easy and exhilarating; the work of creation is slow, laborious and dull. That is one of the lessons of the twentieth century. It is also one reason why conservatives suffer such a disadvantage when it comes to public opinion. Their position is true but boring, that of their opponents exciting but false.
Because of this rhetorical disadvantage, conservatives often present their case in the language of mourning. Lamentations can sweep everything before them, like the Lamentations of Jeremiah, in just the way that the literature of revolution sweeps away the world of our frail achievements. And mourning is sometimes necessary; without ‘the work of mourning’, as Freud described it, the heart cannot move on from the thing that is lost to the thing that will replace it. Nevertheless, the case for conservatism does not have to be presented in elegiac accents. It is not about what we have lost, but about what we have retained, and how to hold onto it.

Curry on Global Warming Statistical Meltdown

Judith Curry, The Global Warming Statistical Meltdown, The Wall Street Journal, October 8, 2014

Mounting evidence suggests that basic assumptions about climate change are mistaken: The numbers don’t add up.

At the recent United Nations Climate Summit, Secretary-General Ban Ki-moon warned that “Without significant cuts in emissions by all countries, and in key sectors, the window of opportunity to stay within less than 2 degrees [of warming] will soon close forever.” Actually, this window of opportunity may remain open for quite some time. A growing body of evidence suggests that the climate is less sensitive to increases in carbon-dioxide emissions than policy makers generally assume—and that the need for reductions in such emissions is less urgent.

According to the U.N. Framework Convention on Climate Change, preventing “dangerous human interference” with the climate is defined, rather arbitrarily, as limiting warming to no more than 2 degrees Celsius (3.6 degrees Fahrenheit) above preindustrial temperatures. The Earth’s surface temperatures have already warmed about 0.8 degrees Celsius since 1850-1900. This leaves 1.2 degrees Celsius (about 2.2 degrees Fahrenheit) to go.

In its most optimistic projections, which assume a substantial decline in emissions, the Intergovernmental Panel on Climate Change (IPCC) projects that the “dangerous” level might never be reached. In its most extreme, pessimistic projections, which assume heavy use of coal and rapid population growth, the threshold could be exceeded as early as 2040. But these projections reflect the effects of rising emissions on temperatures simulated by climate models, which are being challenged by recent observations.

Human-caused warming depends not only on increases in greenhouse gases but also on how “sensitive” the climate is to these increases. Climate sensitivity is defined as the global surface warming that occurs when the concentration of carbon dioxide in the atmosphere doubles. If climate sensitivity is high, then we can expect substantial warming in the coming century as emissions continue to increase. If climate sensitivity is low, then future warming will be substantially lower, and it may be several generations before we reach what the U.N. considers a dangerous level, even with high emissions.

The IPCC’s latest report (published in 2013) concluded that the actual change in 70 years if carbon-dioxide concentrations double, called the transient climate response, is likely in the range of 1 to 2.5 degrees Celsius. Most climate models have transient climate response values exceeding 1.8 degrees Celsius. But the IPCC report notes the substantial discrepancy between recent observation-based estimates of climate sensitivity and estimates from climate models.

Nicholas Lewis and I have just published a study in Climate Dynamics that shows the best estimate for transient climate response is 1.33 degrees Celsius with a likely range of 1.05-1.80 degrees Celsius. Using an observation-based energy-balance approach, our calculations used the same data for the effects on the Earth’s energy balance of changes in greenhouse gases, aerosols and other drivers of climate change given by the IPCC’s latest report.

We also estimated what the long-term warming from a doubling of carbon-dioxide concentrations would be, once the deep ocean had warmed up. Our estimates of sensitivity, both over a 70-year time-frame and long term, are far lower than the average values of sensitivity determined from global climate models that are used for warming projections. Also our ranges are narrower, with far lower upper limits than reported by the IPCC’s latest report. Even our upper limits lie below the average values of climate models.

Our paper is not an outlier. More than a dozen other observation-based studies have found climate sensitivity values lower than those determined using global climate models, including recent papers published in Environmentrics (2012),Nature Geoscience (2013) and Earth Systems Dynamics (2014). These new climate sensitivity estimates add to the growing evidence that climate models are running “too hot.” Moreover, the estimates in these empirical studies are being borne out by the much-discussed “pause” or “hiatus” in global warming—the period since 1998 during which global average surface temperatures have not significantly increased.

This pause in warming is at odds with the 2007 IPCC report, which expected warming to increase at a rate of 0.2 degrees Celsius per decade in the early 21st century. The warming hiatus, combined with assessments that the climate-model sensitivities are too high, raises serious questions as to whether the climate-model projections of 21st-century temperatures are fit for making public-policy decisions.

The sensitivity of the climate to increasing concentrations of carbon dioxide is a central question in the debate on the appropriate policy response to increasing carbon dioxide in the atmosphere. Climate sensitivity and estimates of its uncertainty are key inputs into the economic models that drive cost-benefit analyses and estimates of the social cost of carbon.

Continuing to rely on climate-model warming projections based on high, model-derived values of climate sensitivity skews the cost-benefit analyses and estimates of the social cost of carbon. This can bias policy decisions. The implications of the lower values of climate sensitivity in our paper, as well as similar other recent studies, is that human-caused warming near the end of the 21st century should be less than the 2-degrees-Celsius “danger” level for all but the IPCC’s most extreme emission scenario.

This slower rate of warming—relative to climate model projections—means there is less urgency to phase out greenhouse gas emissions now, and more time to find ways to decarbonize the economy affordably. It also allows us the flexibility to revise our policies as further information becomes available.

Ms. Curry, a professor and former chairwoman of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, is the president of Climate Forecast Applications Network.