Category: Global Warming

Carbon Dioxide (CO2) Emissions Have Little Effect on Global Warming

My colleague Mark Wohar, and his co-author David McMillan, have used sophisticated econometrics to analyze a very long time-series dataset on carbon dioxide (CO2) and temperature. They find that CO2 has little, if any, effect on temperature. Here is the abstract of their paper:

(p. 3683) The debate regarding rising temperatures and CO2 emissions has attracted the attention of economists employing recent econometric techniques. This article extends the previous literature using a dataset that covers 800,000 years, as well as a shorter dataset, and examines the interaction between temperature and CO2 emissions. Unit root tests reveal a difference between the two datasets. For the long dataset, all tests support the view that both temperature and CO2 are stationary around a constant. For the short dataset, temperature exhibits trend-stationary behaviour, while CO2 contains a unit root. This result is robust to nonlinear trends or trend breaks. Modelling the long dataset reveals that while contemporaneous CO2 appears positive and significant in the temperature equation, including lags results in a joint effect that is near zero. This result is confirmed using a different lag structure and Vector Autoregressive (VAR) model. A Generalized Method of Moments (GMM) approach to account for endogeneity suggests an insignificant relationship. In sum, the key result from our analysis is that CO2 has, at best, a weak relationship with temperature, while there is no evidence of trending when using a sufficiently long dataset. Thus, as a secondary result we highlight the danger of using a small sample in this context.

Source:
McMillan, David G., and Mark E. Wohar. “The Relationship between Temperature and CO2 Emissions: Evidence from a Short and Very Long Dataset.” Applied Economics 45, no. 26 (2013): 3683-90.
(Note: bold added.)

Green Threats to Restrict Coal Creates Incentive to Extract More Coal Now

(Wang, p. 1146) The last chapter of the book advances the supply-side analysis and presents the “Green Paradox,” that “(t)he mere announcement of intentions to fight global warming made the world warm even faster” ([Sinn, p. ] 189). The key insight is that demand-reduction measures affect carbon supply through pressure on future prices. Since the existing “green” policies almost always involve increasing stringency and widening coverage over time, the increasing downward price pressure therefore induces resource owners to expedite extraction and thereby exacerbates the climate problem.

For the full review, see:
Wang, Tao. “The Green Paradox: A Supply-Side Approach to Global Warming.” Journal of Economic Literature 50, no. 4 (Dec. 2012): 1145-46.
(Note: bracketed information added.)

The book under review is:
Sinn, Hans-Werner. The Green Paradox: A Supply-Side Approach to Global Warming. Cambridge and London: MIT Press, 2012.

“It Isn’t What You Know that Counts–It Is How Efficiently You Can Refresh”

HalfLifeOfFactsBK2012-12-01.jpg

Source of book image: online version of the WSJ review quoted and cited below.

(p. A17) Knowledge, then, is less a canon than a consensus in a state of constant disruption. Part of the disruption has to do with error and its correction, but another part with simple newness–outright discoveries or new modes of classification and analysis, often enabled by technology.
. . .
In some cases, the facts themselves are variable.  . . .
. . .
More commonly, however, changes in scientific facts reflect the way that science is done. Mr. Arbesman describes the “Decline Effect”–the tendency of an original scientific publication to present results that seem far more compelling than those of later studies. Such a tendency has been documented in the medical literature over the past decade by John Ioannidis, a researcher at Stanford, in areas as diverse as HIV therapy, angioplasty and stroke treatment. The cause of the decline may well be a potent combination of random chance (generating an excessively impressive result) and publication bias (leading positive results to get preferentially published).
If shaky claims enter the realm of science too quickly, firmer ones often meet resistance. As Mr. Arbesman notes, scientists struggle to let go of long-held beliefs, something that Daniel Kahneman has described as “theory-induced blindness.” Had the Austrian medical community in the 1840s accepted the controversial conclusions of Dr. Ignaz Semmelweis that physicians were responsible for the spread of childbed fever–and heeded his hand-washing recommendations–a devastating outbreak of the disease might have been averted.
Science, Mr. Arbesman observes, is a “terribly human endeavor.” Knowledge grows but carries with it uncertainty and error; today’s scientific doctrine may become tomorrow’s cautionary tale. What is to be done? The right response, according to Mr. Arbesman, is to embrace change rather than fight it. “Far better than learning facts is learning how to adapt to changing facts,” he says. “Stop memorizing things . . . memories can be outsourced to the cloud.” In other words: In a world of information flux, it isn’t what you know that counts–it is how efficiently you can refresh.

For the full review, see:
DAVID A. SHAYWITZ. “BOOKSHELF; The Scientific Blind Spot.” The Wall Street Journal (Mon., November 19, 2012): A17.
(Note: ellipses added, except for the one internal to the last paragraph, which was in the original.)
(Note: the online version of the article was dated November 18, 2012.)

The book under review, is:
Arbesman, Samuel. The Half-Life of Facts: Why Everything We Know Has an Expiration Date. New York: Current, 2012.

The Case for More Climate Adaptations and Fewer Climate Mitigations

ClimatopolisBK2012-11-02.jpg

Source of book image: http://perseuspromos.com/images/covers/200/9780465019267.jpg

(p. 777) Climatopolis begins with the assumption that our future will bring some combination of higher temperatures, sea level rise, more intense natural disasters, and changes in precipitation and drought conditions. The forecast is considered inevitable because of humanity’s deep and (p. 778) growing dependence on energy from fossil fuels, the burning of which generates emissions that cause climate change. In a way that some readers are likely to find overly pessimistic, dismissive, or both, Kahn asserts that we are unlikely to invent a “magical” technology that allows us to live well without producing greenhouse gases. He is equally skeptical about whether geo-engineering will help stabilize the climate. So when it comes to facing a future that includes climate change, Kahn has concluded as soon as page 5 that “unlike a ship, we cannot turn away.”

Economics is, after all, the dismal science, but early pessimism in Climatopolis quickly gives way to an overall optimistic theme. It is first encountered, somewhat surprisingly, in a chapter titled “What We’ve Done When Our Cities Have Blown Up.” With examples that range from fires and floods to wars and terrorist attacks, Kahn makes the case that we humans are a surprisingly resilient species. Among the lessons he draws are that destruction often triggers economic booms, people learn from their mistakes, cities are shaped by the accumulation of small decisions by millions of self-interested people, and when conditions are bad in one location people migrate to where it is better.
Kahn gets traction out of the notion that people “vote with their feet,” and he describes how climate change will affect where people want to go. Rising temperatures will cause Sun Belt cities in the United States to suffer, for example, while northern cities such as Minneapolis and Detroit will become more attractive places to live.
. . .
Climatopolis . . . cautions against maladaptive policies, and the recommendation here will be familiar to economists: prices should be left undistorted to reflect real costs and risks. Kahn is critical of a policy in Los Angeles under which people who demand more water pay a lower marginal price, and thereby face exactly the wrong incentive for conservation as water becomes increasingly scarce. He also points to the problems of subsidized insurance or caps on premiums for residents in climate-vulnerable areas, as these policies only promote greater vulnerability. What is more, Kahn would like us to stop treating people who move into harm’s way as victims in need of a bailout when natural disasters strike. He writes that, “Ironically, to allow capitalism to help us adapt to climate change, the government must precommit to not protect ‘the victims’.”

For the full review, see:
Kotchen, Matthew J. “Review of Kahn’s Climatopolis.” Journal of Economic Literature 49, no. 3 (September 2011): 777-79.
(Note: ellipses added.)

Book under review:
Kahn, Matthew E. Climatopolis: How Our Cities Will Thrive in the Hotter Future. New York: Basic Books, 2010.

Preindustrial Icelanders Adapted to Adverse Global Cooling

(p. 254) We investigate the effect of climate on population levels in preindustrial Iceland. We find that short-term temperature changes affect the population growth rate. In particular, a 1ºC decrease in temperature causes about 0.57 percent decrease in the population growth rate for the two subsequent years, for a total effect of 1.14 percent. This effect appears to attenuate as the growth rate returns to trend in subsequent years. We also quantify the extent to which eighteenth- and nineteenth-century Icelanders adapt to long-run climate change. In particular, the data suggest that long-run adaptation to climate takes about 20 years and reduces the effect of cold shocks by about 60 percent. Our results also allow us to approximate the effect of permanent climate change on steady-state population levels. This approximation suggests that steady state population levels decrease by 10 percent to 26 percent for each 1ºC of sustained adverse temperature change.
(p. 255) . . .
If contemporary poor agricultural populations behave like their eighteenth- and nineteenth century Icelandic counterparts, then our results suggest that adverse climate change (which now refers to warming, not cooling) will have three effects. First, in the short run it will lead to a significant decrease in population growth rates. Second, over the course of a generation, adaptation will offset about 60 percent of the short run effects. Finally, in the long run, we expect a decrease in steady-state populations.

For the full article, from which the above conclusion is quoted, see:
Turner, Matthew A., Jeffrey S. Rosenthal, Jian Chen, and Chunyan Hao. “Adaptation to Climate Change in Preindustrial Iceland.” American Economic Review 102, no. 3 (May 2012): 250-55.
(Note: underlining added; the underlined words appeared on p. 254 of the print issue, and on p. 255 of the online issue, of the article.)

Government Disaster Relief Crowds Out Private Self-Protection

(p. 242) This paper has investigated the role of natural disaster shocks in determining gross migration flows, controlling for other place-based features. Using two micro datasets, we documented that in the 1920s and 1930s population was repelled from tornado-prone areas, with a larger effect on potential in-migrants than on existing residents, while flood events were associated with net inmigration. The differential migration responses by disaster type raises the question of whether public efforts at disaster mitigation counteract individual migration decisions. The nascent investment in rebuilding and protecting flood-prone areas could provide one example of public investment crowding out private self-protection (i.e., migration).
(p. 243) In future work, we plan to explore the role of New Deal disaster management more directly by exploiting variation across SEAs in federal expenditures and representation on key congressional committees. We predict that residents of areas that received federal largesse after a disaster in the 1930s will be less likely to move out and that new arrivals may be more likely to move in, while residents of areas that benefited less from New Deal spending will continue to use migration as a means of self-protection.

For the full article, from which the above conclusion is quoted, see:
Boustan, Leah Platt, Matthew E. Kahn, and Paul W. Rhode. “Moving to Higher Ground: Migration Response to Natural Disasters in the Early Twentieth Century.” American Economic Review 102, no. 3 (May 2012): 238-44.

Global Warming Expands Range of Brown Argus Butterfly

BrownArgusButterfly2012-09-03.jpg “The brown argus butterfly has expanded its range in England.” Source of caption and photo: online version of the NYT article quoted and cited below.

(p. D3) A butterfly species in England is expanding its range, thanks to climate change.

In the current issue of Science, researchers at the University of York report that the brown argus butterfly has spread its reach in England northward by about 50 miles over 20 years as a warmer climate allows its caterpillars to feed off wild geranium plants, which are widespread in the countryside.

For the full story, see:
SINDYA N. BHANOO. “OBSERVATORY; A Butterfly Takes Wing on Climate Change.” The New York Times (Tues., May 29, 2012): D3.
(Note: the online version of the article has the date May 24, 2012.)

The results summarized above are reported to the scientific community in:
Chen, Ching, Jane K. Hill, Ralf Ohlemüller, David B. Roy, and Chris D. Thomas. “Report; Rapid Range Shifts of Species Associated with High Levels of Climate Warming.” Science 333, no. 6045 (August 19, 2011): 1024-1026.

Ice Melts too Slowly for Obama Backed Arctic Oil Project

ArcticDrillingMap2012-09-03.jpgSource of map: online version of the WSJ article quoted and cited below.

(p. B1) Royal Dutch Shell . . . is spending billions of dollars to drill the first oil wells in U.S. Arctic waters in 20 years, backed by an Obama administration eager to show it wasn’t opposed to offshore exploration.

But the closely watched project isn’t going the way the company or the government hoped–illustrating the continuing challenge of plumbing for natural riches in one of the world’s most unforgiving locations.
Sea ice in the Chukchi and Beaufort seas off the northern Alaska coast was slow to break up this year, leaving the drilling areas inaccessible much later than anticipated.

For the full story, see:
TOM FOWLER. “Shell Races the Ice in Alaska; Delays Put $4.5 Billion Arctic Drilling Plan in Danger of Missing Window Before Next Freeze.” The Wall Street Journal (Mon., August 20, 2012): B1-B2.
(Note: ellipsis added.)
(Note: the online version of the article has the date August 19, 2012.)

Economists Optimistic that Economy Can Adapt to Climate Change

EconomicsOfClimateChangeBK2012-08-28.jpg

Source of book image: http://www.bibliovault.org/thumbs/978-0-226-47988-0-frontcover.jpg

(p. 222) Efficient policy decisions regarding climate change require credible estimates of the future costs of possible (in)action. The edited volume by Gary Libecap and Richard Steckel contributes to this important policy discussion by presenting work estimating the ability of economic actors to adapt to a changing climate. The eleven contributed research chapters primarily focus on the historical experience of the United States and largely on the agricultural sector. While the conclusions are not unanimous, on average, the authors tend to present an optimistic perspective on the ability of the economy to adapt to climate change.

For the full review, see:
Swoboda, Aaron. “Review of: The Economics of Climate Change: Adaptations Past and Present.” Journal of Economic Literature 50, no. 1 (March 2012): 222-24.

Book under review:
Libecap, Gary D., and Richard H. Steckel, eds. The Economics of Climate Change: Adaptations Past and Present, National Bureau of Economic Research Conference Report. Chicago: University of Chicago Press, 2011.

Global Warming Heretic Svensmark May Be the Next Shechtman

(p. C) The list of scientific heretics who were persecuted for their radical ideas but eventually proved right keeps getting longer. Last month, Daniel Shechtman won the Nobel Prize for the discovery of quasicrystals, having spent much of his career being told he was wrong.
“I was thrown out of my research group. They said I brought shame on them with what I was saying,” he recalled, adding that the doyen of chemistry, the late Linus Pauling, had denounced the theory with the words: “There is no such thing as quasicrystals, only quasi-scientists.”
The Australian medical scientist Barry Marshall, who hypothesized that a bacterial infection causes stomach ulcers, received similar treatment and was taken seriously only when he deliberately infected himself, then cured himself with antibiotics in 1984. Eventually, he too won the Nobel Prize.
. . .
Perhaps it’s at least worth guessing which of today’s heretics will eventually win a Nobel Prize. How about the Dane Henrik Svensmark? In 1997, he suggested that the sun’s magnetic field affects the earth’s climate–by shielding the atmosphere against cosmic rays, which would otherwise create or thicken clouds and thereby cool the surface. So, he reasoned, a large part of the natural fluctuations in the climate over recent millennia might reflect variation in solar activity.
Dr. Svensmark is treated as a heretic mainly because his theory is thought to hinder the effort to convince people that recent climatic variation is largely manmade, not natural, so there is a bias toward resisting his idea. That does not make it right, but some promising recent experiments at CERN (the European Organization for Nuclear Research) raise the probability that Dr. Svensmark might yet prove to be a Shechtman.

For the full commentary, see:
MATT RIDLEY. “MIND & MATTER; Is That Scientific Heretic a Genius–or a Loon?” The Wall Street Journal (Sat., November 12, 2011): C4.
(Note: ellipsis added.)

Dinosaur Belches and Farts Made More Global Warming Gas than All of Today’s Sources

(p. A6) Gassy dinosaurs may have spewed so much methane into the air that it could have helped warm the climate tens of millions of years ago, when temperatures were much higher than today, a team of U.K. scientists reported Monday.
The stomach gas released each year by a group of long-necked, plant-eating dinosaurs, which included the world’s largest known land animals, may have equaled the total amount of methane produced every year today from all natural, agricultural and industrial sources, the researchers said Monday in the journal Current Biology. Methane, a greenhouse gas, is 23 times as effective at trapping heat in the atmosphere as carbon dioxide.
The new scientific work highlights the importance of wildlife, livestock and other natural sources of greenhouse-gas emissions in shaping the global climate.
As with cows, sheep and buffalo today, these plant-eating dinosaurs, known as sauropods, likely digested their leafy greens with the help of methane-producing microbes in their stomachs that fermented the plant matter after it was chewed and swallowed. Generally, other plant eaters and creatures that eat meat, including people, don’t digest their food this way and pass gas that is mostly nitrogen and carbon dioxide, with traces of methane and hydrogen.
Cattle belching and gas account for about 20% of U.S. methane emissions, according to the Environmental Protection Agency.

For the full story, see:
ROBERT LEE HOTZ. “Dinosaur Gas Emissions May Have Warmed Air.” The Wall Street Journal (Tues., May 8, 2012): A6.
(Note: online version of the story is dated May 7, 2012.)

The academic article on sauropod methane emissions is:
Wilkinson, David M., Euan G. Nisbet, and Graeme D. Ruxton. “Could Methane Produced by Sauropod Dinosaurs Have Helped Drive Mesozoic Climate Warmth?” Current Biology 22, no. 9 (May 8, 2012): R292-R93.