Topic: Energy and Environment

Current Wisdom: New Research Calls into Question High Rates of Sea Level Rise

The Current Wisdom is a series of monthly articles in which Patrick J. Michaels, director of the Center for the Study of Science, reviews interesting items on global warming in the scientific literature that may not have received the media attention that they deserved, or have been misinterpreted in the popular press.


In its 2007 Fourth Assessment Report, the Intergovernmental Panel on Climate Change (IPCC) projected that as a result of warming primarily caused by anthropogenic greenhouse gas emissions, global mean sea level would rise from 1990 through 2100 from 0.18 to 0.59 meters (7 to 23 in.) with perhaps another 0.1 to 0.2 meters (4 to 8 in.) on top of that if the rates of ice loss from Greenland and Antarctica continued to grow linearly (from their 1993-2002 rates).

Some of our colleagues who are of a particularly “concerned” persuasion accused the IPCC of being far too conservative in these estimates; it’s true that the IPCC’s central estimate of 15 inches is hardly alarming.  NASA’s Jim Hansen went as far as to accuse the IPCC and others of “scientific reticence” (Hansen claims that scientists are generally reluctant to announce bad news. Judge that one for yourself.) with regard to sea level rise. For his part, Hansen shares no such reticence, and doesn’t mind telling anyone who asks (and many who don’t) that we should be expecting upwards of 6 meters (236 in.) of sea level rise in a hundred years.  He has even stated that the majority of this could occur by 2100. Clearly, there is a world of difference (and a different world) between the IPCC central estimate of 15 inches and Hansen’s 20 feet.

As if on cue, a bunch of apparently non-“reticent” scientists suddenly emerged, trying to show that the IPCC was wrong and of course, that things are “worse than we thought”.

They developed a technique that, to the non-perseverators in the crowd, seems quite reasonable, a “semi-empirical” method which ties historical sea level rise to the rate of global mean temperature change.  They used this relationship rather than the computer-generated rises in sea level that come out of climate models, which is what backs the IPCC projections. Instead they only used the global temperature change projections from the same climate models, and then coupled those with their semi-empirical relationship between temperature and sea level to make their projections. Such a technique almost invariably yields greater rates of sea level rise, with the upper end of the range of projected values often exceeding 1 meter (39 in.) by the year 2100.

One potential problem is that the empirical relationship between sea level and global temperature may not be valid—even though it seems simple and straightforward.  A new multi-authored study argues cogently that indeed the semi-empiricists have fallen into this simple trap.

CO2 Benefits Outweigh Climate Stressors: Chinese Wheat

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

In the vast majority of laboratory and field experiments, the benefits of higher atmospheric carbon dioxide (CO2) concentrations for plants (including food crops) generally outweigh the negative impacts from climate change. And this is even assuming the “dumb farmer scenario” that we recently blogged, in which farmers and agronomists don’t develop new production techniques, technologies, crop varietals, etc., to adapt to change, turning expected losses into gains. There is overwhelming evidence such as the remarkably robust increase that has occurred in the yield of most of the world’s major crops when grown in developing or developed nations. In other words, adding CO2 to the atmosphere may be a win-win situation for the world’s vegetation, but we digress…

Here, we’ll highlight a new study showing that including the fertilization effect of higher CO2 concentrations in a crop model of wheat grown in China turns projections of future climate change-driven reductions in crop yields into CO2-driven yield increases.

The study was conducted by researchers Yujie Liu and Fulu Tao of the Chinese Academy of Sciences and will soon be published in the Journal of Applied Meteorology and Climatology. Liu and Tao used a complex crop model to evaluate the changes in wheat production (which accounts from 22% China’s primary food production), in the main wheat cultivation areas in China under three climate change scenarios—global temperature increases of 1°, 2°, and 3°C. They modeled the crop response both with and without considering the fertilization impacts of additional atmospheric CO2 concentrations (which presumably produced the warming) and compared the results. Here is their summary:

There is a high probability of decreasing (increasing) changes in yield and water use efficiency under higher temperature scenarios without (with) consideration of CO2  fertilization effects. Elevated CO2 concentration generally compensates for the negative effects of warming temperatures on production. Moreover, positive effects of elevated CO2 concentration on grain yield increase with warming temperatures. The findings could be critical for climate change-driven agricultural production that ensures global food security.

Findings and conclusions like these are a breath of carbon dioxide-enhanced fresh air in a world of climate gloomsaying.

Reference:

Liu, Y., and F. Tao, 2012. Probabilistic change of wheat productivity and water use in China for global mean temperature changes of 1, 2, and 3°C. Journal of Applied Meteorology and Climatology, doi:10.1175/JAMC-D-12-039.1, in press.

A Poor Excuse for Even Poorer Legislation

According to The Hill, yesterday Senate Environment and Public Works Committee Chairwoman Barbara Boxer (D-CA) told reporters, “I am going to form a climate change caucus, because people are coming up to me, they really want to get into this. I think Sandy changed a lot of minds.”

Changed a lot of minds about what?   As I have pointed out, the link between “superstorm” Sandy and anthropogenic climate change is weak, and weaker still is our understanding of whether climate change strengthened or weakened Sandy. But regardless of whether or not human greenhouse gas emissions impacted Sandy in some detectable way, it is certain that Congressional attempts to drive down U.S. greenhouse gas emissions will have absolutely zero detectable impact of such storm systems, and any other type of extreme weather you can think of.

Why? Because, as I have shown, under business-as-usual scenarios, the U.S. greenhouse gas emissions are only expected to be responsible for maybe 7% of the total global human greenhouse effect impact over the course of this century.  Detecting a human impact on extreme weather systems is already hard enough (due to human-signal to natural-noise ratio problems), and detecting only 7% of it is impossible (and 7% is the best case scenario if all U.S. greenhouse gas emissions forever ceased starting tomorrow, which, I can assure you, will not be the case).

Sandy is a poor excuse to pursue even poorer legislation.

The Latest Greenland Kerfluffle: If Their Science Can’t Be Refuted, Smear ‘Em

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

About a year and a half ago, we were co-authors (along with Dr. Oliver Frauenfeld from Texas A&M University) on a paper published in the Journal of Geophysical Research in which we presented a nearly 225-year reconstruction of surface snow melt across Greenland (Figure 1).

Our reconstruction was based on long-term temperature records from the southern Greenland coast along with historic indicators of the atmospheric circulation in the North Atlantic Ocean. We found that in addition to the period since about the year 2000, there was an extended (multi-decadal) period in the early portion of the 20th century where the amount of surface snowmelt was elevated above the long-term average.  We concluded from this that since there did not appear to be a large increase in the rate of global sea level rise during the early 20th century period of elevated ice melt—a melt driven primarily by warmer than normal temperatures—that Greenland’s contribution to global sea level rise during the current period of high temperatures was likely to remain relatively “modest,” at least for the next few decades.

Figure 1. Reconstructed history of the total ice melt extent index over Greenland, 1784–2009. Observed values of the ice melt index (blue solid circles), reconstructed values of the ice melt index (gray open circles), the 10 year trailing moving average through the reconstructed and fitted values (thick red line), and the 95% upper and lower confidence bounds (thin gray lines) (from Frauenfeld et al., 2011).

Neither our methods, nor or findings were overly controversial—or so we thought.

Shortly after our paper was published, one of the reviewers of our paper, a noted snow/ice researcher who has spent a lot of time studying Greenland, Dr. Jason Box, came forwarded and denounced our work. On his blog (in posts he has subsequently removed), he attacked our work both from a scientific standpoint as well as deriding it with a few ad hominems (for example “Examining the 2nd [Knappenberger] and 3rd [Michaels] authors’ credentials, a climate change denialist pattern emerges”).

On both accounts we felt he was wrong (of course) and offered a rebuttal.

But perhaps the strongest argument that our results were scientifically sound comes from an ironic source—the results of new research findings from Jason Box himself!

These new findings from Box, although not yet fully available, have been incorporated into another research project that has recently been published (Gregory et al., 2012) and thus we can get a sneak peek at them.

The solid black line in Figure 2 (below) shows Box’s reconstruction of the sea level rise contribution from Greenland back into since the mid-1800s.

Figure 2. Various estimates of the time series of the Greenland ice-sheet mass contribution to global-mean sea-level rise. The reconstructions are plotted as ten-year running time-means of the sea-level equivalent of the rate of change of mass of the Greenland ice-sheet with respect to the mean of 1961–1990. The solid black line, labeled “B” is the net mass balance, including both surface mass balance and ice discharge from Jason Box. The horizontal dotted line indicates zero. The vertical lines indicate the years in which major volcanic eruptions occurred (from Gregory et al., 2012).

Notice the strong resemblance of Box’s reconstruction of the sea level contribution from Greenland with our reconstruction of the surface snow melt across Greenland.  The snow melt/sea level contribution is currently very high, was relatively low in the 1970s, 1980s, and 1990s, was high from the mid-1920s through the late 1960s, and was lower in the 1800s.

Considering that there are other factors besides snowmelt (like snow accumulation and calving glaciers) that contribute to Greenland’s net contributions to sea level rise, the two curves are remarkably similar. This is a strong indication that whatever is driving snowmelt (regional temperature) is also driving the net sea level contribution.

All of which we wrote in our paper:

This record of ice melt indicates that the melt extent observed since the late 1990s is among the highest likely to have occurred since the late 18th century, although recent values are not statistically different from those common during the period 1923–1961, a period when summer temperatures along the southern coast of Greenland were similarly high as those experienced in recent years. Our reconstruction indicates that if the current trend toward increasing melt extent continues, total melt across the Greenland ice sheet will exceed historic values of the past two and a quarter centuries

…The forces acting in concert with ice melt across Greenland to produce higher global sea levels currently, should also have been acting during the extended high‐melt conditions from the mid‐1920s to the early 1960s.

And we also added this concerning the significance of Greenland’s contribution to the total global sea level rise:

[T]here is no indication that the increased contribution from the Greenland melt in the early to mid 20th century, a roughly 40 year interval when average annual melt was more or less equivalent to the average of the most recent 10 years (2000–2009), resulted in a rate of global sea level rise that exceeded ~mm/yr.  This suggests that Greenland’s contribution to global sea level rise, even during multidecadal conditions as warm as during the past several years, is relatively modest.

Figure 3 (anther figure from the new paper from Gregory et al., 2012) shows the breakdown of the factors contributing to the global rise in sea level of the past century and a half.  Greenland’s contribution (based on Box’s reconstruction) is the pale green line (labeled “Greenland-B” in the legend). I think it is pretty fair to characterize this as “modest.”

Figure 3. Observational (black) and a reconstructed (red) time series of global mean sea-level rise (thick lines, with 5–95% observational uncertainty shaded), also showing the contributions to the latter (thin lines), identified by the time series initials in the key (from Gregory et al., 2012).

Why was such a big deal was made about our research results and “denialist” credentials when subsequent results, made by the very person who went ad hominem, completely replicate our findings?

References:

Box, J. E., Greenland ice sheet mass balance reconstruction. Part III: Marine ice loss and total mass balance (1840–2010). Journal of Climate, submitted (as cited by Gregory et al., 2012).

Frauenfeld, O.W., P.C. Knappenberger, and P.J. Michaels, 2011. A reconstruction of annual Greenland ice melt extent, 1785-2009. Journal of Geophysical Research, 116, D08104, doi: 10.1029/2010JD014918.

Gregory, J., et al., 2012. Twentieth-century global-mean sea-level rise: is the whole greater than the sum of the parts? Journal of Climate, doi:10.1175/JCLI-D-12-00319.1, in press.

Suffer the Little Children

But maybe think twice before taking them as authorities on complex environmental and economic matters.

The used lunch trays Emily Fox took home about four years ago from the loading dock outside her elementary school were gross, some still plastered with ketchup. Emily stacked the trays in piles of 10. She wanted to know just how many polystyrene lunch trays Piney Branch Elementary School students went through in a day.  “Three hundred and twenty-five,” said Emily, now 12…

On Friday, the Hermosa Beach City School District in Southern California started replacing foam trays with recycled paper trays once a week, thanks in part to the advocacy of Max Riley, a fourth-grader at Hermosa Valley School, and his sister Reece, a second-grader.

“No Foam Friday” will run through the end of the school year, and the siblings say they’re pushing for permanent change.

Max said he worries about the health repercussions of littering Earth with foam.

Exporting Natural Gas

Suddenly, due to improved drilling techniques, the U.S. is overflowing with natural gas, driving down domestic prices. But foreign prices remain high, which means there is an opportunity for us to export natural gas.  Unfortunately, the infrastructure does not currently exist. To transport natural gas across the ocean, you have to liquefy it first. We have the facilities to import liquefied natural gas, but not to liquefy it ourselves and export.  In order to start exporting, we need to build the appropriate facilities, which requires regulatory approval from the Energy Department. A number of applications have been made to build new facilities.

So why wouldn’t the Energy Department approve this?  Some are arguing that allowing exports would raise prices for domestic consumers and manufacturers, and this would be bad for American users of natural gas.

For more on all this, see the Washington Post here and the NY Times here.

Normally, free trade is about whether or not to allow imports, but preventing exports in an effort to help domestic interest groups is really just the same situation in reverse.  The Washington Post has a good editorial in which they argue for allowing exports.  As they put it:

USUALLY, OPPONENTS of freer trade argue that Americans shouldn’t be buying so many cheap products from abroad, sending their cash overseas. But when it comes to exporting some of this nation’s abundant supplies of natural gas, those who oppose opening up to the world turn that logic on its head — arguing, strangely, that Americans shouldn’t be trying to sell this particular product to other nations, bringing money into the country in the process. Both arguments are unconvincing, and for the same reason: When countries can buy and sell to each other, their economies do what they are best at, producing more with less and driving economic growth.

That’s well put, but let me just add one thing: Under our international trade agreements, we have promised not to restrict exports.  We can’t restrict exports just to keep domestic prices down. In fact, we have already brought a successful WTO complaint against China for doing similar things.  If we want others to play by the rules, we have to do so as well.

So, not only is allowing exports of natural gas good policy, it is what we have promised to do, and what we are demanding of others.

The Current Wisdom: ‘Dumb People’ Syndrome

The Current Wisdom is a series of monthly articles in which Patrick J. Michaels, director of the Center for the Study of Science, reviews interesting items on global warming in the scientific literature that may not have received the media attention that they deserved, or have been misinterpreted in the popular press. Occasionally — as in this edition — we examine recent global warming perceptions that are at odds with reality.

“The habitability of this planet for human beings really is at risk.”
–Al Gore, July 18, 2007

The notion that people just can’t adapt to change (and therefore that governments must regulate change) is known as “Dumb People Syndrome” (DPS).  Given the fact that the planet is “habitable” (meaning  that there large numbers of people) over a mean annual temperature range of approximately 40°C , Gore’s statement—which is about a few degrees C, at best—is quintessential DPS.  

DPS has its subtypes, such as “Dumb Farmer Syndrome”, in which there’s agricultural Armageddon as the world’s farmers fail to adapt to warming conditions.  It’s not only preposterous, it’s inconsistent with history.

Farmers aren’t dumb, and there are incentives for their supply chain—breeders, chemical manufacturers, equipment companies, etc.—to produce adaptive technologies.  Corn is already much more water-use efficient than it was, thanks to changes in genetics, tillage practices, and farm equipment.  The history of U.S. crop yield bears strong witness (Figure 1).

Figure 1. U.S. national corn and wheat yields, 1900-2012 (source: USDA National Agricultural Statistics Service).

A look at the horrible crop year of 2012 is instructive. Corn yield drops about 38 bushels per acre  from what’s known as the “technological trend line.”  Because the “expected” yield—thanks to  technology—with good weather is so high (around 160 bushels/acre), that’s a drop of about 24%, which is simply unremarkable when compared to the other lousy weather years of 1901 (36%), 1947 (21%), 1983 (29%) and 1988 (30%).  Did we mention that the direct fertilization effect of atmospheric CO2  has resulted in a  corn yield increase of approximately seven per cent?

Most assessments of the impacts of climate change give some credence to DPS. Below is one of the  “Key Findings” from the report Global Climate Change Impacts in the United States produced by the U.S. Climate Change Global Change Research Program (USGCRP), which was used as a major support for  the U.S. Environmental Protections Agency’s “Endangerment Finding”  that human carbon dioxide emissions are a threat to health and welfare. According to the USGCRP:

Crop and livestock production will be increasingly challenged.

Many crops show positive responses to elevated carbon dioxide and low levels of warming, but higher levels of warming often negatively affect growth and yields. Increased pests, water stress, diseases, and weather extremes will pose adaptation challenges for crop and livestock production.

Now compare that to the corresponding “Key Finding” from our report Addendum: Global Climate Change Impacts in the United States which is an independent (from the USGCRP) assessment of the scientific literature relating to environmental changes and how they may impact U.S. agriculture:

Crop and livestock production will adapt to climate change.

There is a large body of evidence that demonstrates substantial untapped adaptability of U.S. agriculture to climate change, including crop-switching that can change the species used for livestock feed. In addition, carbon dioxide itself is likely increasing crop yields and will continue to do so in increasing increments in the future.

Another example of the DPS relates to projections of the effects  of more or stronger  heat waves on human mortality.  Everyone has heard—especially after last summer—how human use of fossil fuels to produce energy will increase the frequency and severity of killer heat waves.

Here is how the USGCRP sees it, according to the “Key Messages” from the “Human Health” chapter of their report:

Increases in the risk of illness and death related to extreme heat and heat waves are very likely.

History shows that things don’t work this way.

Why? Because people are not dumb. Instead of dying in increasing numbers as temperatures rise, people take better precautions to protect themselves from the heat.

Numerous examples of this abound, including some pioneering work that we did on the subject about 10 years ago.  We clearly demonstrated that across the U.S., people were becoming less sensitive to high temperatures, despite the fact that high temperatures were increasing. In other words, adaptation was taking place in the face of (or, perhaps even because of) rising temperatures. Adaptations include expanding use of air conditioning, increasing public awareness, and more widespread community action programs.

What was interesting  about our work is we didn’t even need global warming to drive increasing heat waves.  All we needed was economic activity that concentrates in cities.  As they grow, buildings and pavement retain the heat of the day and impede the flow of ventilating winds.  In recent years, the elevation of night temperatures here in Washington (where your tax dollars virtually guarantee economic growth),  compared to the countryside, has become truly remarkable.  But you won’t find  an increase in heat-related mortality.  Instead, there’s been a decrease.
Our research was limited to major cities across the United States. But similar findings have since been reported for other regions of the world, the most recent being the from the Czech Republic.

Czech researchers Jan Kyselý and Eva Plavcová recently published the results of their investigation of changes in heat-related impacts there from 1986 through 2009.  What they found sure wasn’t surprising to us, but surely must come as quite a shock to the fans of DPS.

Declining trends in the mortality impacts are found in spite of rising temperature trends. The finding remains unchanged if possible confounding effects of within-season acclimatization to heat and the mortality displacement effect are taken into account. Recent positive socioeconomic development, following the collapse of communism in Central and Eastern Europe in 1989, and better public awareness of heat-related risks are likely the primary causes of the declining vulnerability. The results suggest that climate change may have relatively little influence on heat-related deaths, since changes in other factors that affect vulnerability of the population are dominant instead of temperature trends. It is essential to better understand the observed nonstationarity of the temperature-mortality relationship and the role of adaptation and its limits, both physiological and technological, and to address associated uncertainties in studies dealing with climate change projections of temperature-related mortality.

Findings like these, along with our own work, caused us to conclude in our Addendum report that:

“In U.S. cities, heat-related mortality declines as heat waves become stronger and/or more frequent.”

Evidence is much more compelling in  support of a “smart people” diagnosis than its opposite.  In fact, if humankind was really as dumb as the fans of DPS would have us believe, we wouldn’t be around  today to hear their doomsaying, because Homo sapiens would have been wiped out during vastly larger environmental swings (in and out of ice ages, for example) in our past,  than those expected as a consequence of the burning of fossil fuels to produce the energy that powers our world—a world in which the human life expectancy, perhaps the best measure of our level of “dumbness” or “smartness”—has more than doubled over the last century and continues to grow ever longer.

Simply put, we are not “dumb” when it comes to our survival and our ability to adapt to changing environmental conditions, but “scientific” assessments that assume otherwise most certainly are.

References:

Davis, R.E., Knappenberger, P.C., Novicoff, W.M., Michaels, P.J., 2002. Decadal changes in heat-related human mortality in the Eastern US. Climate Research, 22, 175–184.

Davis, R.E., Knappenberger, P.C., Novicoff, W.M., Michaels, P.J.,2003a. Decadal changes in summer mortality in U.S. cities. International  Journal of Biometeorology, 47, 166–175.

Davis, R.E., Knappenberger, P.C., Michaels, P.J., Novicoff, W.M., 2003b. Changing heat-related mortality in the United States. Environmental Health Perspectives, 111, 1712–1718.

Davis, R.E., Knappenberger, P.C., Michaels, P.J., Novicoff, W.M., 2004. Seasonality of climate-human mortality relationships in US cities and impacts of climate change. Climate Research, 26, 61–76.

Jan Kyselý, j., and E. Plavcová, 2012.Declining impacts of hot spells on mortality in the Czech Republic, 1986–2009: adaptation to climate change? Climatic Change, 113, 437-453.