Tag: The Atlantic

To Spur Technology Innovation, Stop Pulling on the Rope

I spent the morning at The Atlantic’s Washington Ideas Forum. Before the big names were to do their spiels during the afternoon today and tomorrow morning, there were a series of breakout sessions, among which was one on “Technology Innovation.”

Our suggested “points to ponder” were:

  1. Can our nation regain our competitive edge through innovation?
  2. Will our knowledge and information-based workforce continue to offer cutting-edge technologies to improve the way we live and work?
  3. What measures can we implement to foster creativity and encourage companies to grow intelligently? and
  4. Will the paradigm of how people work, think and communicate be meaningfully transformed as a result of technology? Or is this another short-term trend, with no long term changes?

At least one of the other participants thought the summary of the discussion I gave in the latter half was pretty good, so I’ll share my takeaway here roughly as I did there—maybe sounding just a little more “Cato-y” here.

First, note the conspicuous use of collective pronouns in the first three discussion points. They obscure the goals and actors quite nicely, summarizing to: There is an undefined group out there that we want to have do an undefined set of things amounting to innovation.

I was reminded of the metaphor for spurring economic progress (if I recall, and I don’t recall where I first heard it): Spurring economic progress is like pushing a rope. You really can’t do it. Someone has to pull it, and the job of policymakers is simply to not pull on the wrong end.

In our brainstormy session, the ideas generally focused on pushing our end of the rope. “We” need more basic research and R&D. “We” need more and better education in science and technology. “We” need more inspired leadership, the spur of a new Sputnik.

These things are all probably inputs to innovation in some sense. None of them, I don’t think, will produce innovation as a matter of course. And nobody knows where to direct these efforts so that they do produce innovation.

A few other ideas emerged, ways that public policy can stop pulling on the rope. One was letting immigrants stay in this country—particularly the ones who have just earned advanced degrees—and welcoming them to stay. Another one was reducing the role of patent strategy in tech-business decision-making. Patents seem no longer to be primarily a spur to innovation, but a strategic arsenal used offensively or defensively by tech giants. A third idea that nearly surfaced was tax cuts, but its author in the conversation pivoted from what other countries are doing with tax policy to “national competitiveness,” never actually saying that U.S. tax cuts would spur business activity and innovation.

Arriving back at the office, I chanced to come across some thinking that would have contributed mightily to the discussion: NYU professor of economics Bill Easterly talking about the relationship of individual rights to economic growth, development, and innovation:

[I]ndividual rights is also a way to mobilize all the knowledge in society that we need to make the economy work. It’s the individual that has the particular knowledge so that they know how to run their factory, to employ people, to be a worker themselves, to start new businesses.

We’ll talk later about examples—like the guy in Rwanda, who stumbled upon a very unexpected success. He figured out—this is not something anybody would have predicted—that Rwanda could prosper by exporting gourmet coffee, which you can find in New York’s best coffee shops.

One reason that worked so well for Rwanda, is they have a tremendous infrastructure problem. It’s very hard to get heavy stuff shipped abroad because they are landlocked, they’re surrounded by countries with lousy roads, lousy ports. But gourmet coffee is something that you can create with lots of labor, which Rwanda does have a lot of, and it has very high value-to-weight ratio. So you just put it on the airplane, and ship it to New York.

So, there was no expert economist that flew in and told Paul Kagame, the autocrat of Rwanda, “Here’s the plan: Identify gourmet coffee as the growth industry worldwide. That’s the recipe.” None of that happened.

These successes are always a surprise. That’s why the expert top-down plan doesn’t work. You need the entrepreneur, you need the consumer, you need the market feedback, you need the democratic feedback, and all of this is built on this large edifice at the bottom of individual rights.

Defend people’s rights to own and use their property, however they might imagine to do that, then watch them deliver their surprises. That’s innovation policy. Stop pulling on the rope.

Soft Heart, Soft Head?

Yesterday, I came across a short Atlantic essay on the plight of children in Accra’s Abogbloshie slum entitled “The Hardware Scavengers of Ghana.” One particular sentence stood out for succinctly crystallizing the problem, and for its near-perfect internal inconsistency: “These kids are shortening their lives, but they don’t have any other options.”

You see, if they have no other options, the toxic job of electronics recycling—burning insulation off copper wires, applying degreasing solvents with bare hands, and so on—is extending their lives, not shortening them. According to the underlying article and interview on Mongabay.com, many of the recyclers come from Northern Ghana to escape poverty, maltreatment, “food insecurity,” and sectarian strife. The choice is not between recycling and school. It is between encountering carcinogens and neurotoxins or encountering violence, starvation, and death.

The Atlantic and Mongabay.com articles focus on the environmental and biological consequences of e-waste, and the responses they broach do the same. The Ghanian government might limit import of used electronics, but this would shrink the nation’s access to valued and productive communications equipment. Had it the capacity, the government might try to prevent dumping of e-waste where these recyclers can access it.

Solving the problem of e-waste might be a comfort to readers of the Atlantic concerned with their own environment and susceptibility to cancer. But if the statement about poor Ghanians’ options is true, such “solutions” would consign children and young men to death of starvation, violence, and war. That’s not the outcome I would prefer, even if it’s hidden from me.

A couple of lessons emerge from this compact tale. One is: never, ever invite me to your cocktail party. I will go about picking the scab off group consensus on faraway economic and social problems. And I will say, “See? That redness and pus? You haven’t fixed this.”

More importantly, the solutions that extend the lives of electronic waste recyclers may have nothing to do with controlling “e-waste.” These articles frame the problem as we would in the green, wealthy west. Economic development of all kinds in Ghana may give these youth better options than e-waste recycling, according them sustenance and safety, and perhaps eventually access to education.

I don’t know what improvements in trade policy (ours or theirs), rule of law, taxation or regulation might bring the wealth to Ghana that sustains its people better. I wish Ghana the relative luxury of controlling toxic waste, moving people from slum to suburbs, and so on. But if softness in our hearts leads us to soft-headedly sweep Ghana’s poorest from bad health conditions into conditions of death by starvation and violence, I think that would compound the tragedy.

Laura Tyson’s Confused Case for a Second Stimulus

I was a bit critical of Laura Tyson’s New York Times article on “Why We Need a Second Stimulus.” Apparently I wasn’t nearly critical enough.

The Nation and National Public Radio are advising President Obama to “stop listening to infrastructure-phobic advisers like Larry Summers and start taking counsel from Laura Tyson, a member of his Economic Recovery Advisory Board who argues that $1 trillion in infrastructure investment is needed over the next five years.”

At The Atlantic, senior editor (and Boston Globe columnist) Joshua Green thinks Laura Tyson’s article “underscored what a loss it is for the Obama administration that it couldn’t manage to find a place for her on its economic team.” Mr. Green can’t imagine why a Berkeley professor who wants to add an extra trillion to federal spending wouldn’t be the ideal budget director.

In the article that so impressed Mr. Green, Tyson wrote, “The primary cause of the [current] labor market crisis is a collapse in private demand… By late 2009, in response to unprecedented fiscal and monetary stimulus, household and business spending began to recover. But by the second quarter of this year, economic growth had slowed to 1.6 percent.”

Combining “fiscal and monetary stimulus” in a single phrase is a clumsy way to conceal the irrelevance of   “fiscal stimulus” (debt-financed federal spending) to GDP growth in 2009. Fiscal stimulus means the Treasury sells more bonds. Monetary stimulus means the Fed buys more bonds. To discuss those transactions as if they had the same effect is just another mysterious Keynesian incantation.  

Tyson claims there is “too little appreciation for how stimulus spending has helped stabilize the economy and how more of the right kind of government spending could boost job creation and economic growth.” She wants much more spending on unemployment benefits (a paradoxical definition of a jobs program) and on aid to state and local governments (where unemployment rates are relatively low). 

To argue for more borrowing and spending, however, Tyson cannot credit monetary policy for helping the recovery. Because she explicitly advocates much more spending on “unemployment benefits and aid to state governments” (not just “infrastructure”), Tyson has to demonstrate that changes in federal spending (not Fed policy) explain why the economy appeared to be recovering in late 2009 but faltering by the second quarter of 2010. It is not enough to allude to simulations from Mark Zandi’s famously incorrect forecasting model, as the CEA and CBO have done. Tyson needs to show us a fact or two. She didn’t even try. She even got the size of Obama’s stimulus bill wrong, citing last year’s antiquated $787 billion figure that the Congressional Budget Office (CBO) has revised twice since January.

In reality, the 2009 stimulus bill was mostly about extending unemployment benefits, expanding Medicaid, dispensing small checks (refundable tax credits) and other schemes to rob Peter and pay Paul. Such transfer payments add nothing to GDP; they just discourage work. The increase in federal nondefense purchases (such as ”shovel-ready” projects) contributed only two-tenths of one percent (0.2) to the change in GDP in 2009. That was no larger than in 2008 when the Recovery Act did not exist. And even that trivial sum is merely an accounting gain rather than a net economic gain, because federal borrowing is no free lunch. The reason Keynesian accounting is no substitute for economics is that governments can only spend what Danny DeVito called “OPM” (other peoples’ money). To claim that such spending is a net addition to “aggregate demand” is to ignore those other people — namely, current and future taxpayers.

The timing of Obama’s so-called stimulus spending has been totally inconsistent with Tyson’s description of how the economy supposedly responded in the past and present, and why she expects growth to slow by a percentage point or two next year unless the feds spend more on multi-year jobless benefits and deficit-sharing with the states. In its latest whitewash, the CBO “now estimates that the total impact over the 2009–2019 period will amount to $814 billion. Close to half of that impact is estimated to occur in fiscal year 2010, and about 70 percent of ARRA’s budgetary impact will have been realized by the close of that fiscal year.” With half of the spending in fiscal 2010 and 30 percent in 2011 and beyond, that means just 20 percent of the $814 billion ($163 billion) had been spent by the end of October 2009. Yet it was in late 2009 when Tyson claims the stimulus had the most impact. 

Tyson worries that “by next year, the [fiscal] stimulus will end.”  That’s wrong too. The CBO estimates that 30 percent of the spending ($244 billion) will occur in fiscal 2011 (January to October) and beyond to 2019.

Unfortunately, Ms. Tyson’s reference to the second quarter’s GDP is entirely unrelated to her diagnosis of the problem as being “a collapse in private demand.” GDP does not measure private demand because it subtracts imports. Yet spending on imports is just as much a part of “demand” as is spending on domestic goods and services. Real gross domestic purchases increased at a 4.9 percent annual rate in the second quarter, up from 3.9 percent in the first. Neither figure suggests any paucity of private spending.

The second quarter surge in imports (which largely accounts for the wide gap between domestic purchases and GDP) looks like a statistical fluke. “Real” imports appeared to rise so much mainly because import prices supposedly fell at a 9.5 percent annual rate (which means a 2.38 percent rise in the quarter, multiplied by four to get the annual rate). By contrast, import prices rose at a 14.6 percent annual rate in the first quarter and at a 24.8 percent rate in the fourth quarter of 2009. Those figures say more about the folly of converting smallish price changes into annual rates than they do about the real economy. Besides, imports fell 2.1 percent in July and exports rose 1.8%, so the questionable second quarter trade figures did not indicate a lasting trend.

Tyson did not bother to figure out how large the first stimulus bill was, or when the borrowed loot was spent. She did not bother to look up the negligible contribution of federal spending to recent changes in GDP, and she confused GDP with domestic demand. 

The press kept telling us that Tyson was almost certain to replace Peter Orszag as OMB director, and then to replace Christina Romer as head of the Council of Economic Advisers. Yet such plums keep slipping from her fingers, to the dismay of her fans at The Nation, NPR and The Atlantic. This is rare evidence of good judgment from the Obama White House.

David Goldhill: “A Democrat’s Case For ‘No’ ”

David Goldhill has done it again.

You may recall his article, “How American Health Care Killed My Father,” from the September 2009 issue of The Atlantic.

Now, at HuffingtonPost, he comments on the health care legislation that may soon face a final vote (of some sort) in the House:

[C]ontinuing our Party’s almost unquestioned conflation of health insurance with health care, the central feature of the proposed “reform” is further extension of our flawed insurance-based system…[D]espite the Administration’s recent heated rhetoric, most of the entrenched health industry interests are quietly or openly in favor of this bill. Should the bill become law, I suspect we will look back at it as an industry bailout…

How…can Democrats in the depths of a recession support a massive tax increase on middle-class job creation…? How…could we justify diverting even more of middle class income to support our broken system of care, further starving families of funds for all their other needs? Most uninsured Americans lack insurance only temporarily; how many of them would trade lesser lifetime job prospects and lower disposable income for the short-term retention of health insurance?…

If the legislation had any real prospect of controlling health care spending, would the pharmaceutical industry be funding the “yes” campaign?

As a former Democrat who hung door knockers for Michael Dukakis in 1988, I know the heavy heart with which he writes.  Read the whole thing.

Watch the video to hear Goldhill’s story:

The Myth of ‘Market Failure’ in Health Care

One argument in favor of a government overhaul of the health care system is that the free market had its chance, and failed when it comes to providing the best possible care.  But as David Goldhill discovered while researching for the September cover article in The Atlantic, the United States has anything but a free-market health care system.

He explains his findings below:

For real market-based reform, see Cato’s new Policy Analysis, “Yes, Mr. President: A Free Market Can Fix Health Care.

I Would Rather You Just Said “Thank You, Private Schools,” and Went on Your Way…

Some well-known bloggers are being terrible bullies, beating up on private schools.

Felix Salmon kicks things off by hoping the government tightens the definition of a “charitable” organization and begins taxing private schools who don’t “do a bit more to earn it.” Matt Yglesias agrees that private schools are mooching deadbeats and ups the ante, calling them actively harmful as well. Finally, Conor Clarke at The Atlantic agrees, but makes the other two look like panty-waists by proposing the government radically narrow what is considered a charity in the first place.

Yglesias even has the temerity to indict private schools for the failure of NYC public schools:

And as best one can tell, their main impact on the common weal is negative, drawing parents with resources and social capital out of the public school system and contributing to its neglect. You’d have to believe that New York City’s public schools would be both better funded and free of this kind of nonsense if a larger portion of the city’s elite were sending their kids to them.

Really? Would we have to believe what Yglesias says? No, it’s not “the best one can tell.” According to the evidence, Yglesias’ breezy, offhand accusation is demonstrably wrong. Increased competition from private schools actually improves public school performance.

And the more kids who leave public to go private, the more money the schools have for the kids who remain.

What ingrates. They complain about the lost tax revenue while dismissing out of hand the billions of dollars that parents and donors spend every year to educate children outside the government system. They dismiss the fact that these parents and donors are saving taxpayers in the neighborhood of $60 Billion a year based on current-dollar public school spending and the number of kids in private schools.

Finally, if this is all about rich people getting a free ride, why aren’t these guys screaming about means-testing public schools? Why shouldn’t we charge rich parents tuition to attend public schools? If a charitable deduction for private schools is so bad, why isn’t a free public education even worse?

Cherry Picking Climate Catastrophes: Response to Conor Clarke, Part II

Conor Clarke at The Atlantic blog, raised several issues with my study, “What to Do About Climate Change,” which Cato published last year.

One of Conor Clarke’s comments was that my analysis did not extend beyond the 21st century. He found this problematic because, as Conor put it, climate change would extend beyond 2100, and even if GDP is higher in 2100 with unfettered global warming than without, it’s not obvious that this GDP would continue to be higher “in the year 2200 or 2300 or 3758”. I addressed this portion of his argument in Part I of my response. Here I will address the second part of this argument, that “the possibility of ‘catastrophic’ climate change events — those with low probability but extremely high cost — becomes real after 2100.”

The examples of potentially catastrophic events that could be caused by anthropogenic greenhouse gas induced global warming (AGW) that have been offered to date (e.g., melting of the Greenland or West Antarctic Ice Sheets, or the shutdown of the thermohaline circulation) contain a few drops of plausibility submerged in oceans of speculation. There are no scientifically justified estimates of the probability of their occurrence by any given date. Nor are there scientifically justified estimates of the magnitude of damages such events might cause, not just in biophysical terms but also in socioeconomic terms. Therefore, to call these events “low probability” — as Mr. Clarke does — is a misnomer. They are more appropriately termed as plausible but highly speculative events.

Consider, for example, the potential collapse of the Greenland Ice Sheet (GIS). According to the IPCC’s WG I Summary for Policy Makers (p. 17), “If a negative surface mass balance were sustained for millennia, that would lead to virtually complete elimination of the Greenland Ice Sheet and a resulting contribution to sea level rise of about 7 m” (emphasis added). Presumably the same applies to the West Antarctic Ice Sheet.

But what is the probability that a negative surface mass balance can, in fact, be sustained for millennia, particularly after considering the amount of fossil fuels that can be economically extracted and the likelihood that other energy sources will not displace fossil fuels in the interim? [Remember we are told that peak oil is nigh, that renewables are almost competitive with fossil fuels, and that wind, solar and biofuels will soon pay for themselves.]

Second, for an event to be classified as a catastrophe, it should occur relatively quickly precluding efforts by man or nature to adapt or otherwise deal with it. But if it occurs over millennia, as the IPCC says, or even centuries, that gives humanity ample time to adjust, albeit at a socioeconomic cost. But it need not be prohibitively dangerous to life, limb or property if: (1) the total amount of sea level rise (SLR) and, perhaps more importantly, the rate of SLR can be predicted with some confidence, as seems likely in the next few decades considering the resources being expended on such research; (2) the rate of SLR is slow relative to how fast populations can strengthen coastal defenses and/or relocate; and (3) there are no insurmountable barriers to migration.

This would be true even had the so-called “tipping point” already been passed and ultimate disintegration of the ice sheet was inevitable, so long as it takes millennia for the disintegration to be realized. In other words, the issue isn’t just whether the tipping point is reached, rather it is how long does it actually take to tip over. Take, for example, if a hand grenade is tossed into a crowded room. Whether this results in tragedy — and the magnitude of that tragedy — depends upon how much time it takes for the grenade to go off, the reaction time of the occupants, and their ability to respond.

Lowe, et al. (2006, p. 32-33), based on a “pessimistic, but plausible, scenario in which atmospheric carbon dioxide concentrations were stabilised at four times pre-industrial levels,” estimated that a collapse of the Greenland Ice Sheet would over the next 1,000 years raise sea level by 2.3 meters (with a peak rate of 0.5 cm/yr). If one were to arbitrarily double that to account for potential melting of the West Antarctic Ice Sheet, that means a SLR of ~5 meters in 1,000 years with a peak rate (assuming the peaks coincide) of 1 meter per century.

Such a rise would not be unprecedented. Sea level has risen 120 meters in the past 18,000 years — an average of 0.67 meters/century — and as much as 4 meters/century during meltwater pulse 1A episode 14,600 years ago (Weaver et al. 2003; subscription required). Neither humanity nor, from the perspective of millennial time scales (per the above quote from the IPCC), the rest of nature seem the worse for it. Coral reefs for example, evolved and their compositions changed over millennia as new reefs grew while older ones were submerged in deeper water (e.g., Cabioch et al. 2008). So while there have been ecological changes, it is unknown whether the changes were for better or worse. For a melting of the GIS (or WAIS) to qualify as a catastrophe, one has to show, rather than assume, that the ecological consequences would, in fact, be for the worse.

Human beings can certainly cope with sea level rise of such magnitudes if they have centuries or millennia to do so. In fact, if necessary they could probably get out of the way in a matter of decades, if not years.

Can a relocation of such a magnitude be accomplished?

Consider that the global population increased from 2.5 billion in 1950 to 6.8 billion this year. Among other things, this meant creating the infrastructure for an extra 4.3 billion people in the intervening 59 years (as well as improving the infrastructure for the 2.5 billion counted in the baseline, many of whom barely had any infrastructure whatsoever in 1950). These improvements occurred at a time when everyone was significantly poorer. (Global per capita income today is more than 3.5 times greater today than it was in 1950). Therefore, while relocation will be costly, in theory, tomorrow’s much wealthier world ought to be able to relocate billions of people to higher ground over the next few centuries, if need be. In fact, once a decision is made to relocate, the cost differential of relocating, say, 10 meters higher rather than a meter higher is probably marginal. It should also be noted that over millennia the world’s infrastructure will have to be renewed or replaced dozens of times – and the world will be better for it. [For example, the ancient city of Troy, once on the coast but now a few kilometers inland, was built and rebuilt at least 9 times in 3 millennia.]

Also, so long as we are concerned about potential geological catastrophes whose probability of occurrence and impacts have yet to be scientifically estimated, we should also consider equally low or higher probability events that might negate their impacts. Specifically, it is quite possible — in fact probable — that somewhere between now and 2100 or 2200, technologies will become available that will deal with climate change much more economically than currently available technologies for reducing GHG emissions. Such technologies may include ocean fertilization, carbon sequestration, geo-engineering options (e.g., deploying mirrors in space) or more efficient solar or photovoltaic technologies. Similarly, there is a finite, non-zero probability that new and improved adaptation technologies will become available that will substantially reduce the net adverse impacts of climate change.

The historical record shows that this has occurred over the past century for virtually every climate-sensitive sector that has been studied. For example, from 1900-1970, U.S. death rates due to various climate-sensitive water-related diseases — dysentery, typhoid, paratyphoid, other gastrointestinal disease, and malaria —declined by 99.6 to 100.0 percent. Similarly, poor agricultural productivity exacerbated by drought contributed to famines in India and China off and on through the 19th and 20th centuries killing millions of people, but such famines haven’t recurred since the 1970s despite any climate change and the fact that populations are several-fold higher today. And by the early 2000s, deaths and death rates due to extreme weather events had dropped worldwide by over 95% of their earlier 20th century peaks (Goklany 2006).

With respect to another global warming bogeyman — the shutdown of the thermohaline circulation (AKA the meridional overturning circulation), the basis for the deep freeze depicted in the movie, The Day After Tomorrow — the IPCC WG I SPM notes (p. 16), “Based on current model simulations, it is very likely that the meridional overturning circulation (MOC) of the Atlantic Ocean will slow down during the 21st century. The multi-model average reduction by 2100 is 25% (range from zero to about 50%) for SRES emission scenario A1B. Temperatures in the Atlantic region are projected to increase despite such changes due to the much larger warming associated with projected increases in greenhouse gases. It is very unlikely that the MOC will undergo a large abrupt transition during the 21st century. Longer-term changes in the MOC cannot be assessed with confidence.”

Not much has changed since then. A shut down of the MOC doesn’t look any more likely now than it did then. See here, here, and here (pp. 316-317).

If one wants to develop rational policies to address speculative catastrophic events that could conceivably occur over the next few centuries or millennia, as a start one should consider the universe of potential catastrophes and then develop criteria as to which should be addressed and which not. Rational analysis must necessarily be based on systematic analysis, and not on cherry picking one’s favorite catastrophes.

Just as one may speculate on global warming induced catastrophes, one may just as plausibly also speculate on catastrophes that may result absent global warming. Consider, for example, the possibility that absent global warming, the Little Ice Age might return. The consequences of another ice age, Little or not, could range from the severely negative to the positive (if that would buffer the negative consequences of warming). That such a recurrence is not unlikely is evident from the fact that the earth entered and, only a century and a half ago, retreated from a Little Ice Age, and that history may indeed repeat itself over centuries or millennia.

Yet another catastrophe that greenhouse gas controls may cause is that CO2 not only contributes to warming, it is also the key building block of life as we know it. All vegetation is created by the photosynthesis of CO2 in the atmosphere. In fact, according to the IPCC WG I report (2007, p. 106), net primary productivity of the global biosphere has increased in recent decades, partly due to greater warming, higher CO2 concentrations and nitrogen deposition. Thus , there is a finite probability that reducing CO2 emissions would, therefore, reduce the net primary productivity of the terrestrial biosphere with potentially severe negative consequences for the amount and diversity of wildlife that it could support, as well as agricultural and forest productivity with adverse knock on effects on hunger and health.

There is also a finite probability that costs of GHG reductions could reduce economic growth worldwide. Even if only industrialized countries sign up for emission reductions, the negative consequences could show up in developing countries because they derive a substantial share of their income from aid, trade, tourism, and remittances from the rest of the world. See, for example, Tol (2005), which examines this possibility, although the extent to which that study fully considered these factors (i.e., aid, trade, tourism, and remittances) is unclear.

Finally, one of the problems with the argument that society should address low probability high impact events (assuming a probability could be estimated rather than assumed or guessed) is that it necessarily means there is a high probability that resources expended on addressing such catastrophic events will have been squandered. This wouldn’t be a problem but for the fact that there are opportunity costs associated with this.

According to the 2007 IPCC Science Assessment’s Summary for Policy Makers (p. 10), “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.” In plain language, this means that the IPCC believes there is at least a 90% likelihood that anthropogenic greenhouse gas emissions (AGHG) are responsible for 50-100% of the global warming since 1950. In other words, there is an up to 10% chance that anthropogenic GHGs are not responsible for most of that warming.

This means there is an up to 10% chance that resources expended in limiting climate change would have been squandered. Since any effort to significantly reduce climate change will cost trillions of dollars (see Nordhaus 2008, p. 82), that would be an unqualified disaster, particularly since those very resources could be devoted to reducing urgent problems humanity faces here and now (e.g., hunger, malaria, safer water and sanitation) — problems we know exist for sure unlike the bogeymen that we can’t be certain about.

Spending money on speculative, even if plausible, catastrophes instead of problems we know exist for sure is like a starving man giving up a fat juicy bird in hand while hoping that we’ll catch several other birds sometime in the next few centuries even though we know those birds don’t exist today and may never exist in the future.