One possible casualty of the endless U.S. budget fight may be the federal subsidy for corn ethanol production. There's been a lot of quiet, and some not-so-quiet, cheering from the environmental community, based on the premise that eliminating the subsidy will lessen nutrient pollution from growing so much corn.
In reality, cutting or repealing the 45-cents-per-gallon ethanol tax credit is unlikely to have much of an effect on planting decisions. As a recent article in the NY Times nicely explained last week, the subsidy is, at this point, unnecessary. Between laws requiring blending of ethanol into gasoline, the federal ethanol mandate, the tariff on imports, the size of the ethanol production industry, and the high price of corn, there's already enough incentive to maintain the status quo in corn production and corn ethanol production.
There are certainly good reasons to eliminate the subsidy. No one should pretend that doing so will solve of the problem of nutrient levels in the Mississippi River and the Gulf of Mexico. That is a far greater challenge.
Sunday, July 17, 2011
Eliminating the US corn ethanol subsidy is no panacea
Wednesday, March 30, 2011
Food prices and the ongoing biofuel debate
People worldwide are being affected by a rise in the price of food. The causes are complex and interacting: last summer's drought in Russia, the price of oil, speculative trading in commodities, economic instability, political unrest on the Middle East, you name it. As Tamino mentions, some people sceptical of efforts to reduce greenhouse gas emissions blame the increase in food prices on those efforts, namely the cultivation of biofuels like corn ethanol. Though I think Tamino's post misses the point of this debate.
The impact of corn ethanol, or an individual drought, or any other individual factor, on the price of a global commodity is very hard to quantify. The diversion of the U.S. corn crop to ethanol production over the past decade has undoubtedly affected food prices, despite U.S. government claims to the contrary. The various factors have interacting, nonlinear effects on the price of each commodity, and the commodity prices each affect the others, so it is hard to work out, say, a coefficient for each driving variable. But that's not the problem.
The real problem with any "climate change mitigation = more corn ethanol = higher food prices" argument is the first part: the claim that producing corn ethanol is addressing climate change.
In reality, the use of ethanol from corn as a fuel might actually result in greater greenhouse gas emissions than the use of gasoline, because of the land and energy required to grow the corn, harvest the corn, and convert the corn to ethanol. As such, the primary motivation for the expansion of corn ethanol production in the US is not climate change. Ethanol production is about appeasing regional interests, maintaining of the agricultural subsidy system and reducing reliance on imported fuels, probably in that order.
The only reason that corn ethanol gets promoted by politicians in the U.S. as a solution to climate change is that in the current political atmosphere, very few actual climate change mitigation proposals can pass, and because of some effective lobbying and the power of the Presidential primary process, expanding corn ethanol production looks like climate change mitigation to the public.
Throw out the word biofuels and people might think action is being taken to address climate change. Look at the acutal conversion efficiencies and total lifecycle greenhouse gas emissions of the current feedstocks in the U.S. and you find a different story.
There is definitely reason to be concerned about the market effects of diverting so much of the U.S. corn crop to ethanol production. The real key to the story, the one to to look for in the coming months, is the price of meat. The majority of cereals and oils, the commodities for which the price has spiked the most, are used to generate animal feed. If you look back to 2008, you’ll see that the price of meat is likely to spike next.
This dynamic demonstrates the real battle we face in the future. It’s not food vs. fuel, it is feed vs. fuel. If the world wants to keep using the most productive croplands to provide biofuel feedstocks, we had better be prepared to eat less or much more expensive meat.
Wednesday, October 06, 2010
Collaborating with industry on publications and climate solutions
The article Geoengineering: The Inescapable Truth of Getting to 350 from online hybrid magazine / academic publication The Solutions Journal appeared in my inbox today.
We can argue back and forth about the societal and ecological implications of geoengineering. That's not the point of this post. What struck me as unique in this particular article is the focus on "bioenergy" solutions, namely 'The Case for Algae', out of all the many possible geoengineering proposals. It turns out the article is written by two academics along with the chief technology and science officer of Cellana. From the Cellana website:
Cellana was established in 2007 as a joint venture between Shell and HR BioPetroleum to develop technology for the sustainable and commercial production of biofuels and animal feed from algae
Let's be clear. Developing and implementing solutions to climate change will require working with industry. We live in a capitalist system; it is willful blindness to ignore the efforts of profit-seeking outfits. So there's not necessarily anything unethical about working with industry - there certainly are cases where it will be unethical, but it is not absolute guaranteed ethical violation. Having worked on the ecological impacts of biofuels, I've certainly encountered academic scientists who consult with algae companies, because the scientists concluded algae is a far better feedstock than corn.
Does the same apply to publishing peer-reviewed articles? Is this a good example of academics working with companies to find solutions, or of a journal bridging the gap between the ivory tower and the real world? Or is this article example of "the literature" being sullied by industry influence?
Friday, October 23, 2009
Carbon consequences of the biofuels land use cascade
I've written here before about the land use cascade, the sequence of land transformations and land use changes that follow a change in one region.
A new Policy Forum in Science argues that ignoring the cascading carbon consequences of converting lands for biofuels will undercut global efforts to reduce greenhouse gas emissions.
The logic is not new. If croplands and pasture lands are converted to biofuel production, then some other forest or grassland must be cleared to produce the crops or providing the grazing area taken away by the biofuel production. It might happen in the neighbouring county. It might happen on another part of the planet. Either way, it will release soil carbon and plant carbon to the atmosphere (more immediately via burning or later via respiration and decomposition).
The authors argue that we need a new accounting system:
The accounting now used for assessing compliance with carbon limits in the Kyoto Protocol and in climate legislation contains a far-reaching but fixable flaw that will severely undermine greenhouse gas reduction goals (1). It does not count CO2 emitted from tailpipes and smokestacks when bioenergy is being used, but it also does not count changes in emissions from land use when biomass for energy is harvested or grown. This accounting erroneously treats all bioenergy as carbon neutral regardless of the source of the biomass, which may cause large differences in net emissions. For example, the clearing of long-established forests to burn wood or to grow energy crops is counted as a 100% reduction in energy emissions despite causing large releases of carbon.
If it is not fixed, this "accounting problem" has and will continue to cause poor national and international policy decisions.
The Kyoto Protocol caps the energy emissions of developed countries. But the protocol applies no limits to land use or any other emissions from developing countries, and special crediting rules for "forest management" allow developed countries to cancel out their own land-use emissions as well. Thus, maintaining the exemption for CO2 wrongly treats bioenergy from all biomass sources as carbon neutral, even if the source involves clearing forests for electricity in Europe or converting them to biodiesel crops in Asia.
This accounting error has carried over into the European Union's cap-and-trade law and the climate bill passed by the U.S. House of Representatives. Both regulate emissions from energy but not land use and then erroneously exempt CO2 emitted from bioenergy use.
How could it be fixed? The authors argue for a more full and fair accounting of emissions caused by biofuels or bioenergy.
The straightforward solution is to fix the accounting of bioenergy. That means tracing the actual flows of carbon and counting emissions from tailpipes and smokestacks whether from fossil energy or bioenergy. Instead of an assumption that all biomass offsets energy emissions, biomass should receive credit to the extent that its use results in additional carbon from enhanced plant growth or from the use of residues or biowastes. Under any crediting system, credits must reflect net changes in carbon stocks, emissions of non-CO2 greenhouse gases, and leakage emissions resulting from changes in land-use activities to replace crops or timber diverted to bioenergy.
This full accounting is necessary but will be difficult to implement given the uncertainty in soil carbon budgets and the complexity of the land use cascade.
Sunday, July 05, 2009
Abuse of science and logic by the National Corn Growers Association
The National Corn Growers Association released a report arguing that there is no connection between the use of nitrogen fertilizers on corn in the Midwestern US and the seasonal “Dead Zone” in the Gulf of Mexico.
There is no point mincing words about what this “analytical white paper”. It is the corn equivalent of irrational climate change skepticism. This is one truly shoddy piece of work. I encourage others in the scientific community to respond either independently or to append the critique offered here.
First, let’s review the actual science.
The “dead zone” in question, discussed many times before on this blog, is generated most summers on the continental shelf of the northern Gulf of Mexico. Nutrients originating in the Mississippi River Basin in the spring fuel the production of algae (primary production) in the surface waters along the continental shelf. The algae die and sink to the bottom, or something else eats the algae and the fecal matter from the something else sinks to the bottom. All that organic matter needs to decompose, and the process of decomposition (respiration) consumes oxygen. So the bottom waters on the continental shelf during the summer become very depleted in oxygen, or “hypoxic”.
Scientific research over the last few decades has shown that the increase in nitrogen flow from the Mississippi and neighbouring Atchafalaya Rivers since the 1950s has driven the development of these large seasonal periods of hypoxia. The evidence comes from basic ecological theory on nutrient limitation, lab experiments, tracking of the Mississippi River plume, long-term data analysis, sediment cores, isotopic analysis and mathematical modeling. While other nutrients like phosphorus and silica are important, nitrogen is the primary culprit.
There are many possible explanations for the increased flow of nitrogen out of the Mississippi-Atchafalaya River Basin (MARB) including fertilizer use, manure use, NOx emissions from cars and sewage. A simple nutrient budget shows nitrogen fertilizer use in the MARB has increased 20-fold since the 1950s. And today, most of that nitrogen fertilizer is applied to corn fields. Measurements and mathematical modeling of nitrogen loss from corn fields show that corn production is a primary source of nitrogen to the Mississippi and Atchafalaya Rivers, and hence, a primary driver of the development of what's come to be called the “Dead Zone”.
The author of the NCGA report (from the consulting firm StrathKirn Inc.) attempt to counter the mass of scientific evidence with the following largely baseless and unscientific arguments. Basically, he throws a bunch of stuff at the wall to see if anything sticks. I’ll go one by one through the report's chain of five incorrect and comically inconsistent assertions:
Assertion #1: Oxygen levels on the continental shelf are not low in comparison to other parts of the ocean.
This is misleading and irrelevant. First, the large regions of upwelling in the open ocean have low oxygen concentration due to high primary production. There’s no sense in contrasting the naturally and persistently low oxygen levels in the eastern Pacific to the intermittent, seasonal hypoxia on the continental shelf of the Gulf of Mexico. Second, even if there were some sense in this comparison, the data resolution of these maps is far too poor to capture a hypoxia area, which, while among the largest in the world, is still at its largest on the order of 20,000 km2 [here’s a test – can you clearly delineate New Jersey on that map?]. The global map of marine nitrogen concentrations is even more ridiculous. The data is far too coarse to capture the plume of the Mississippi River.
Assertion #2: Hypoxia doesn’t affect the fishery (not there is any hypoxia).
The report shows no change in fish catch over the years. As Steve Carpenter of the University of Wisconsin mentioned in an e-mail, the problem is the report analyses data on fish landings, not fishing effort. The boats may come back with the same weight in fish – but it takes more time and money to get those fish.
Assertion #3: Nitrogen from the Mississippi and Atchafalaya doesn’t cause the hypoxia (not that the hypoxia affects the fishery, or that there is any hypoxia in the first place).
This argument is advanced through a series of graphs relating annual nitrogen export, annual river flow and the annual extent of the hypoxic zone. There are a number of problems here. The nitrogen and flow data are shown only since 1985, despite data existing back to the 1950s. If the graph went back thirty years, you’d see the 2-3fold increase in nitrogen export occurred between the 1950s and the 1980s. Instead, the author reports no evidence of a trend in nitrogen of hypoxia since 1993. That’s not the issue – the issue is the hypoxic zone began growing large in the 1980s because fertilizer use increased between the 1950s and the 1980s, and further increases in corn planting, say for ethanol production, may further increase the average annual extent of hypoxia.
The other glaring problem with this argument is that the report uses no statistics whatsoever. For example, after a chart of nitrogen export and hypoxia extent since 1985 is this unsupported passage:
Again, there appears to be an association between water flow and the amount of nitrite (NO2) plus nitrate (NO3), but these do not relate well to the size of the hypoxic zone (except that they are all low in the year 2000). Thus, many of the statements about the relationship between water flow, nitrogen, and the size of the hypoxic zone are inaccurate.
Some actual statistical analysis, or frankly, just eyeballing the graph, would suggest that there is a significant relationship between the annual nitrogen export from the MARB and the annual extent of the hypoxic zone. It is not a perfect one-to-one relationship between nitrogen and the extent of hypoxia because of how the weather effects mixing of oxygen in the Gulf, the load of other nutrients and a myriad of other mitigating factors. If the author had done any research, they’d find proper statistical analysis and explanations in dozens of published papers, including this one of from my own work, a 2007 paper in Limnology and Oceanography:
Between 1985 and 2004, there is a significant relationship (r2 > 0.61) between midsummer hypoxia area and the May + June nitrate flux (Fig. 1). The strength of this relationship is limited by a number of other variables, including the advection of sub-pycnoclinal waters on the continental shelf, summer tropical storms that increase vertical mixing, recycling of N sequestered in shelf sediments during previous years, and the input of other nutrients such as phosphorus (Rabalais et al. 2002; Scavia et al. 2003; Wawrik et al. 2004).
Assertion #4: Not very much nitrogen is applied to corn (not that nitrogen causes hypoxia, or that hypoxia affects the fishery, or that there is any hypoxia in the first place).
The report displays a graph illustrating that non-crop uses of nitrogen fertilizer, like fertilizer used on lawns, is equal to or greater than the use of nitrogen fertilizer on corn. The problem, or I should say, the most glaring problem? It is national data. Over 90% of the corn grown in the US, and over 90% of the nitrogen fertilizer applied to corn in the US, is grown in the MARB. A 1999 EPA report estimated that non-agricultural fertilizer use is only 5% of total U.S fertilizer use - and that percentage of total fertilizer use in the major producing states of the Corn Belt.
Assertion #5: No nitrogen runs off of corn fields (not that much nitrogen is applied to corn, or that nitrogen causes hypoxia, or that hypoxia affects the fishery, or that there is any hypoxia in the first place).
The report proudly claims that the same amount of nitrogen is now removed during the corn harvest (i.e. in the grain) than is applied as fertilizer, so there can’t be any extra nitrogen left over to run off into the river. Fertilizer use efficiency has indeed increased over the years thanks to genetic technology and improved management. In other word, farmers are getting higher yields with the same amount of nitrogen fertilizer. That is positive news.
But the calculation in the paper is full of flaws. To name just one: the contention that fertilizer inputs = crop outputs = no nitrogen runoff only makes sense if fertilizer were the one and only source of nitrogen to the crops. For one, there is the mineralization of nitrogen in the soil – plant matter on the ground is naturally broken down by microbes, a process that released nitrogen from the plant matter to replenish the soil. This is a fundamental part of soil chemistry. The whole reason the Midwest is good land for growing corn is the high natural mineralization rates!
Final take-home message of the report: The US has a lot of golfers.
The report concludes that all other analyses are ignoring all the fertilizer applied to lawns and present maps and data to support this conclusion. The calculations are extremely suspect. First, the author assumes that the fraction of land devoted to lawns is greater in the MARB than in the rest of the country. Analysing the lawn data, eyeballing the national map, or simply reflecting about the fact that 4/5ths of the US population live outside the MARB, shows that this is a ridiculous assumption. Second, the report assumes that all the fertilizer not applied to corn, wheat, soybeans or cotton – which amounts to about 25% of annual fertilizer sales - is applied to lawns. This ignores all other crops grown in the United States, as well as all the fertilizer applied to rangelands and forests.
The report goes on to argue:
Since most lawns are cut and mulched there is relatively little removal of N, unlike the grain in corn. Consequently, a major portion of the N applied to lawns may be available for leaching… the net N available for leaching per acre is almost infinitely higher for lawns than from corn.
Not only does this argument incorrectly imply that no plant residue whatsoever is ever left behind after harvest to replenish the soil, it ignores the fact that unlike lawns, many corn fields are artificially drained by pipes or drainage tiles, such that excess nitrogen easily leaches to the nearest stream.
All told, the NCGA report is an embarrassment.
There are some legitimate outstanding questions about the nitrogen-hypoxia problem and definitely some legitimate critiques of the media coverage. In particular, the coverage often gives the mistaken impression that corn is the only source of nitrogen, that the hypoxic zone covers a large fraction of the Gulf of Mexico, that water at all depths is hypoxia, and that hypoxia is a permanent phenomena, rather than a seasonal occurrence. The NCGA could have issued on a report on those real concerns. Instead, it issued this dishonest mess of half-truths and pseudo-science.
Wednesday, July 23, 2008
The conflict between ethanol and animal feed
The NY Times reports that at least one major livestock producing state is objecting to the use of corn for ethanol, because it diverts corn away from, and raise the price of, animal feed:
Gov. Rick Perry of Texas is asking the Environmental Protection Agency to temporarily waive regulations requiring the oil industry to blend ever-increasing amounts of ethanol into gasoline. A decision is expected in the next few weeks. Mr. Perry says the billions of bushels of corn being used to produce all that mandated ethanol would be better suited as livestock feed than as fuel.
This are exactly the type of conflict we wrote about in our study on corn-based ethanol production and the Gulf of Mexico "Dead Zone".
From the conclusion:
The land cover analysis in this study raises questions about the availability of land to radically increase ethanol or other biofuel production. Reaching the proposed biofuel production goals will lead to trade-offs between cropland demands for food, feed, and fuel, even when the use of ethanol coproducts as feed is considered. The mitigation scenario demonstrates that reducing the cultivation of animal feed, the majority domestic use of corn and soybeans (2), is one way of attaining the croplands necessary for biofuel production.
A sharp reduction in feed cultivation and animal production in the U.S. is purely hypothetical; it would require a substantial change in culture and the reduction of an industry that provides income and employment to a large number of Americans. However, given the probable ceilings on cropland area, grain yields and use of ethanol coproducts as animal feed, a gradual decrease in use of corn and soybeans for animal feed may be a necessary consequence of the projected increase in demand for biofuels.
Tuesday, June 17, 2008
A perfect storm for the Dead Zone
The massive floods in the Midwestern US are likely to fuel the largest Gulf of Mexico Dead Zone in recorded history. The image at right is from the NY Times and the National Weather Service.
Nitrogen applied to crops like corn in the Midwest is the major driver of the now famous Dead Zone, as I've described in a number of previous posts and this Google News commentary. The blame for the high nitrogen levels in the Mississippi and this year's record Dead Zone forecast is being placed on the production of more corn for ethanol. A more complete explanation would be that the surge in corn production, and, hence, fertilizer use, the past few years has made nitrogen pollution more sensitive to the climate than ever.
Nitrogen and hydrology are tightly linked in the Mississippi River Basin, and other agriculturally intensive river basins, thanks to nature and to humans. Several nitrogen 'species' like nitrate are highly soluble. What has exacerbates things in the Mississippi is activities like wetlands, installing artificial drainage under fields and channelizing rivers that reduce chances for nitrogen to be consumed before moving downstream. The result is the amount of nitrogen that the Mississippi sends to the Gulf can actually be predicted from the rainfall in the Corn Belt.
In coverage of our recent paper on corn and the Dead Zone, the prediction that the US Energy Policy would increase average nitrogen loading by 10-34% drew most of the attention. What might be missed is that the nitrogen loading could be much higher if the conditions are wetter.
The reason this matters is the the continental shelf of the Gulf of Mexico has a memory. The usual tale is that the Dead Zone grows each spring and summer when the big flood of Mississippi nitrogen arrives weather and water conditions are ripe for algae growth (it breaks up in the fall when the waters cool and mix, reintroducing oxygen to the bottom waters). However, nitrogen from previous years that is deposited in the sediments can also be recycled and feed algae growth. In other words, the system remembers a big flood of nitrogen. For example, during the 1993 Mississippi floods, the Dead Zone grew to a then-record 17,600 km2; the next year, it grew to an almost equal 16,600 km2, despite 31% less nitrate flowing down the Mississippi. That's just one reason why it is critical to consider climate and climate variability in ecological management and policy.
This year, the Dead Zone is projected to reach over 25,000 km2 in size, 20% greater than the previous maximum. What will that mean for 2009? For 2010? The longer you wait, the harder problems like the Dead Zone are to solve.
Tuesday, April 15, 2008
Food prices and the use of corn
The rise in food prices is finally garnering serious attention from the media and from world governments. The latest NY Times piece has this precious quote from Senator Charles Grassley of Iowa:
“You make ethanol out of corn,” he said. “I bet if I set a bushel of corn in front of any of those delegates, not one of them would eat it.”
Never mind the fact that a bushel is more than 25 kg of corn, Sen. Grassley (in claiming that the diversion of corn for ethanol is not affecting food prices) rather accidentally describes the exact problem. We don't eat the corn. In the U.S., the majority of the subsidized crops corn and soybeans (~75% in our most recent look at the economic data) are used for animal feed. And it is the rise in demand for meat, together with biofuel demand, high oil prices and droughts overseas, that is driving up food prices.
Wednesday, April 09, 2008
Growing ethanol on conservation lands
One of the assumptions in our recent paper on the impact of increasing corn ethanol production on the Gulf of Mexico Dead Zone is that farmers could start to plant crops on land enrolled in a federal conservation program.
The latest data shows that may be happening. The area of U.S. croplands enrolled in the federal Conservation Reserve Program decreased from by 2.12 million acres since July of last year (using February data), a drop of 6%. The NY Times reports that the drop was caused by high commodity prices, driven in part by the ethanol boom.
Farmers sign a ten-year contract when entering land in the CRP. As it stands, that land cannot be returned to cultivation until the contract expires. It is worth remembering that, despite the headlines and echoing blog posts, the area of CRP lands had been increasing for the past ten year, reaching an all-time high last year. This recent drop does not negate those changes. So the real question is what happens to the 9.5 million acres of land for which the contracts expire in the next three years.
Monday, March 10, 2008
Corn ethanol production will worsen the Dead Zone
A new paper by my colleague Chris Kucharik and I looks at the new US Energy Policy, will calls for growing more corn to produce ethanol, will affect the "Dead Zone" in the Gulf of Mexico. For a quick summary, see Reuters, the CBC or AFP (or my 15 Minuten ruhm on German ARD). Wired and Scientific American go into more detail.
The Mississippi dumps a massive amount of nitrogen, largely in the form of the soluble ion nitrate, into the Gulf each spring. It promotes the growth of a lot of algae, which eventually sinks to the bottom and decomposes. This consumes much of the oxygen in the bottom waters, making life tough for bottom-dwelling fish and creatures like shrimp. The Dead Zone has reached over 20,000 km2 in recent years.
The primary source of all that nitrogen is fertilizer applied to corn grown in the Midwest and Central US. Reducing the Dead Zone to less than 5000 km2 in size, as is suggested in US policy, will require up to a 55% decrease in nitrogen levels in the Mississippi.
The new US Energy Policy calls for 36 billion gallons of renewable fuels by the year 2022. Of that, 15 billion can be produced from corn starch. Our study found meeting those would cause a 10-34% increase in nitrogen loading to the Gulf of Mexico.
Meeting the hypoxia reduction goal was already a difficult challenge. If the US pursues this biofuels strategy, it will be impossible to shrink the Dead Zone without radically changing the US food production system. The one option would be to dramatically reduce the non-ethanol uses of corn. Since the majority of corn grain is used as animal feed, a trade-off between using corn to fuel animals and using corn to fuel cars could emerge.
Tuesday, February 12, 2008
Biofuels and the "land use cascade"
As readers of Maribo no doubt heard, two papers in last week’s Science addressed the greenhouse gas emissions that arise from clearing lands for biofuel crop production. It is an important subject that has been widely discussed within the scientific community, including my own collection of colleagues, for the past year or two. You might say these papers are the first to “do the math”. The papers conclude what many carbon cycle experts suspect: that any greenhouse gas benefits that come from using biofuels instead of oil are negated when you include the emissions associated with land clearing.
The publication of both papers at once is enlightening because they tackle slightly different, but complimentary, issues.
Fargione et al. address the direct emissions from the land cleared to plant the actual biofuel crops. The examples includes Brazilian Amazon to soybean biodiesel, Brazilian Cerrado to soybean biodiesel, Brazilian Cerrado to sugarcane ethanol, Indonesian or Malaysian lowland tropical rainforest to palm biodiesel, Indonesian or Malaysian peatland tropical rainforest to palm biodiesel, and US Central grassland to corn ethanol.
Searchinger et al. use a global economic model to look more at the indirect emissions. In the developed world, including Canada and the US , forests or grasslands are not being cleared to plant biofuel crops. Instead, biofuels are being produced on land previously devoted to other crops or from grain diverted from another use (i.e. corn grain goes to the ethanol plant rather than the boat shipping it overseas). The change has a cascading effect on the world market. There is less grain available, which can cause other countries to clear land to feed the market.
I like to call problems like that addressed in the Searchinger et al. paper “land use cascades”. There are countless examples -- one of the my favourites is the effect that the surge in soybean production in the US and Brazil in the 90s had on the Yasawa Islands in Fiji (I tell the whole story is here).
These cascades are becoming increasingly important, and increasingly global in scale. For example, the same thinking needs to be applied to forestry-based carbon credit programs. If a segment of BC coastal rainforest slated for logging is protected, does that mean some other forest must be logged to provide the missing pulp and paper? If so, what effect does that have on the net emissions? We may discover that net greenhouse gas savings only occur if we also reduce demand for the products that would otherwise come from that land either cleared (biofuels) or saved (forest carbon credits). More on that later.
Saturday, January 26, 2008
Greenhouse gases, meat consumption and the Amazon
The Sunday NY Times has a good story on the global environmental burden of meat production, an issue that's been covered here on and off over the past couple years. Meat production, particularly beef, is responsible for a large proportion of the world's greenhouse gas emissions due to the energy required to grow animal feed, the clearing of land for feed crops, N2O emissions from fertilizer application and both N2O and CH4 emissions from the animals themselves. The graph at right shows the consistent rise in per capita consumption in the Americas and Asia over the past 45 years. Meat production and consumption is expected to continue to rise due to rising demand in China and other parts of Asia.
The demand for animal feed, coupled the demand for biofuels, is being felt most of all in the Amazon, the one large area of "unused" and potentially productive farmland left on the planet. The rate of Amazonian deforestation increased in the last few months, and may increase further in the rainy months to come, when most illegal cutting usually occurs.
Wednesday, October 03, 2007
Greenhouse gases from biofuels and the reporting of science
You may have read that a study by Nobel Prize winner Paul Crutzen and colleagues currently under review reports that biofuels, like corn-base ethanol and rapeseed biodiesel, emit more greenhouse gases than the fossil fuels they replace. It was covered by Reuters, the Times (UK) and the magazine Chemistry World (update: podcasts available on Scitizen). The news then bounced all over the internet, appearing in Grist, Green Car Congress, and a number of blogs like Alternapower, Green Diary, Biofuels Digest, Climateer Investing, Earth2Tech, Big Biofuels Blog, Classically liberal, After Gutenberg, Digital Journal, I could go on.
There is one other phrase you are unlikely to have noticed above. Under review.
In this case, that process is still underway. But that's where things get screwy. Unlike other journals, where submitted articles are sent to individual expert reviewers selected by the editors, APC includes an open review process. That means in addition to the normal peer review, anyone in the community can read the submitted paper online and offer comments. Personally, I like the system, as it gives authors a wider array of reviews and helps eliminate the chances that one irrational reviewer will derail a good piece of research.
The unintended consequence of the open discussion, however, is that an unpublished, and hence, unfinished paper is there for anyone to read. The paper can be reported in the media and the public can get the mistaken that the findings are accepted by the scientific community.
Think about this.
How could the N2O from fertilizer offset the GHG reductions from cutting gasoline use, if other studies accounting for GHG from all aspects of biofuel production, including N2O from fertilizer, found that biofuels were, at the worst, a wash with traditional gas? What, then, has this study done to find such a dramatically different result? And how is the scientific community responding?
Monday, July 30, 2007
Dead Zone in Gulf is third largest since 1985
Though I'm reticent to link to any news article under the cable-TV-news-ish heading "Planet in Peril", CNN reports that this summer's Gulf of Mexico dead zone has been measured at about 20, 460 km2 in size. That makes it the third largest since measurement began in 1985.
The hypoxic zone was expected to be unusually large this year because of the high flux of nitrogen -- the nutrient that fuels the high productivity on the continental shelf that leads to the consumption of oxygen from the bottom waters -- from the Mississippi River this spring. The blame can likely be placed on the weather and possibly even the increase in corn planting (due to high prices / ethanol demand).
Now off to grab my cape. The planet is in peril.
Thursday, July 12, 2007
Pros and cons of the US Senate Energy Bill
A couple provisions in the last month's US Senate Energy Bill - technically the Renewable Fuels, Consumer Protection, and Energy Efficiency Act of 2007 - received most of the attention:
i) the increase in CAFE standards, and
ii) the renewable fuels standard.
It turns out both provisions have some quirky loopholes that were missed in much of the mainstream media coverage so far.
1. CAFE standards
With all the political hurdles, any change in CAFE standards is an accomplishment. As this well-researched article in Salon carefully explains, the actual goal -- that automobiles sold in 2020 average 35 mpg -- may not be worthy of that much praise.
First, it sets a rate of increase could be matched or surpassed without any policy:
It takes about a decade for the nation's vehicle fleet to turn over -- for new cars to replace old ones -- so any change to CAFE takes years to have a real impact on the average fuel economy of vehicles on the road... if you averaged the mileage of the most fuel-efficient cars, trucks, SUVs and minivans sold in the U.S. today, you'd already get a combined mileage of 31 miles per gallon... cars that Toyota sells in the United States almost meet the 2013 standard already, getting just shy of 35 miles per gallon... In Japan, the current average is 45 miles per gallon.
Second, the bill gives automakers one big out:
If the National Highway and Traffic Safety Administration can show that it's not "cost effective" for automakers to meet the 35 mpg goal, then it won't have to require them to do so.
These new CAFE provisions may actually get weakened further by the US Congress (where Democratic lawmakers from the automobile-producing states hold some sway). Efficiency will increase a bit without regulation simply due to current market pressures. But, as our carrot-munching friend noted in a comment here, without tougher standards or regulation, people may not have enough incentive to shift from the "safer" large vehicles towards smaller more efficient vehicles.
2. Renewable Fuels Standard
The bill sets a new target of 36 billion gallons of renewable fuels by 2022. Opponents of corn-based ethanol cheered the "capping" of its production at 15 billion gallons.
As part of some ongoing research, a colleague and I read through the renewable fuels portion of the bill for the section on corn. Actually, we just searched for the "corn". Nothing. We tried "maize". Nope.
You see, there is no cap specifically on corn. The target is for 21 billion gallons of "advanced fuels". The remainder, 15 billion, can be conventional ethanol. Flipping back to the beginning of Bill reveals that "advanced" means "fuel derived from renewable biomass other than corn starch." That's where the news of a 15 billion cap came from.
It'll be interesting to discover how this standard will be interpreted. Does a small conversion of corn cellulose or non-starch parts of the corn plant (i.e. relative to the use of the starch in the grain) allow corn-based ethanol production to be included as an advanced fuel? Will conventional fuels created from sorghum, a crop similar to corn grown in drier parts of the US, or from durum wheat be considered advanced fuels?
Perhaps the intent of the authors in structuring the Bill in this manner was benign. At the very least, the language is very curious.
Friday, June 01, 2007
Ok, this biofuels thing has gone too far
MEXICO CITY (Reuters) - Mexican farmers are setting ablaze fields of blue agave, the cactus-like plant used to make the fiery spirit tequila, and resowing the land with corn as soaring U.S. ethanol demand pushes up prices.
The switch to corn will contribute to an expected scarcity of agave in coming years, with officials predicting that farmers will plant between 25 percent and 35 percent less agave this year to turn the land over to corn.
Friday, March 30, 2007
What the record corn crop actually means
U.S. farmers are expected to plant 37 million hectares of corn this spring, the largest area of corn since “the Allies invaded Normandy”. It is a 15% increase from last year, all thanks to the demand for ethanol. At the same time, the planted area of soybeans is expected to be 11% lower than last year.
That’s 90.5 million acres of corn, in American English (sick of getting sent data in pounds, cubic feet per second and acres, I'm a on one-person quest to convert to USDA and the USGS to metric).
The media has been all over this today. The coverage I've seen is largely missing the point.
Corn and soybeans are the two prominent crops in the central U.S. For the past 10-15 years, the “Corn Belt” has really been the “Corn and Soybean Belt”. In 2006, the planted area of corn was 31.9 million ha; of soybeans, 30.6 million hectares. The crops are often grown in rotation – corn on a field one year, soy the next – since the nitrogen-fixing soy helps reduce fertilizer needs on corn (and residual nitrogen from corn helps the soy the next year). Both crops are largely used to generate animal feed, a sizeable chunk of which is exported to Europe and Asia.
We’re not about to discover more fertile farmland in the US. The additional corn to produce ethanol is largely coming two ways:
1. Replacing other crops. Since soybeans and corn are usually grown together, the surge in corn means less soy being grown. That means fewer soy available as feed, both here and overseas.
2. Reducing other uses of corn. The major uses of corn are animal feed, exports (mostly feed), food and now fuel. The domestic animal feed isn’t changing substantially lest we change our diets; the domestic food is a small fraction; the surplus here is coming from exports.
Those headlines about the impending choice between food and fuel? That’s not happening here, at least not yet. Ethanol is being generated in the US via planting more corn (at the expense of soy) and exporting less corn. The result is not less food in the store. It is less grain being sold for feed overseas.
That has market implications and environmental implications overseas(more on the environmental side later). As has been widely reported – the “tortilla effect” in Mexico – the price of corn has been high because the supply is being diverted (from exports for feed) to ethanol. It is important to remember that plenty of other factors affect food and crop prices. People seem to be getting carried away blaming ethanol for everything, like the price of wheat, which is rarely used for feed or to generate ethanol.
As for the US, with a 15% increase in planting of heavily fertilized corn, at the expensive of largely unfertilized soybeans, there may also be a record amount of nitrogen in central US soils this summer. A wet spring means a large hypoxic zone is likely to appear in the northern Gulf of Mexico next summer.
Monday, March 05, 2007
Climate and the Gulf of Mexico "dead zone"
My colleague Don Scavia and I have an article in the latest issue of Limnology and Oceanography about the effect of climate on the development of the seasonal “dead zone” in the Gulf of Mexico.
I’ve written a bit about this issue before on Maribo. The intensification of agriculture in the central US since the 1950s – huge increases in nitrogen fertilizer use, planting of more nitrogen-fixing soybeans, drainage of wetlands, installation of artificial drains under fields – caused a 2-3 fold increase in the amount of nitrogen the Mississippi River delivers to the Gulf of Mexico. The large influx of nitrogen now promotes the growth of a seasonal low oxygen or hypoxic zone each summer on the continental shelf of the northern Gulf of Mexico.
From the 1980s until quite recently, however, agricultural land use and land cover were relatively stable in contrast to the more dramatic changes in the previous three decades (the surge in interest for ethanol may end the relative stability). The one factor that changed the most, year to year, is the weather. Our study examines how this year-to-year variability in rainfall influences the amount of nitrogen flooding down the Mississippi in the spring and the extent of hypoxia in the Gulf.
The study finds that, absent any major changes in land use and land cover, the year-to-year variability in precipitation across the “Corn Belt” (in the previous November and December and in March, April and May) is the primary driver of the year-to-year variability in amount of nitrogen delivered by the Mississippi during the late spring (in May and June). Using this relationship, the study then examines how climate variability affects the potential size of the hypoxic zone and the implications for reducing nitrogen losses and the size of the hypoxic zone. During very wet years, a nitrogen reduction of 50-60% – close to twice the original recommended target – is necessary to reach the goal of minimizing the size of the hypoxic zone (< 5000 km2).
The results are a reminder of the importance of factoring climate variability into water quality or aquatic ecosystem policy, particularly given the changes in climate expected to occur in the coming decades.
Sunday, November 12, 2006
As the corn turns
Last week, I was at an EPA symposium about nutrient pollution in the Mississippi River Basin. Although the seminars had titles like “Nitrogen Processing in Flow-Controlled Backwater Systems of the Upper Mississippi River” and “Nitrogen Removal Capacity of Entire River Networks—Interactions of Geomorphic, Hydraulic and Biological Factors”, the same subject kept cropping up:
Ethanol
In 2004, the production of corn-based ethanol reached 3.4 billion gallons – or 2% of all U.S. gasoline by volume – by far the highest in history. The Energy Policy Act calls for ethanol production to more than double, to 7.5 billion gallons, by the year 2012. Since energy independence is likely to be one of the only areas of agreement between the Bush Administration and the newly Democratic Congress and Senate, it would not be surprising to see an even more aggressive policy emerge in the next couple years.
Every passing mention of the inevitable expansion of corn-based ethanol production brought sighs from many of the participants.
Why? First, most of the people I spoke with agree with the conclusion that the energy derived from corn-based ethanol is, at best, only slightly greater than the energy required in production. It may be net energy loss. Second, the participants of the Symposium have for the most part been working on the difficult challenge of reducing nitrogen pollution in the Mississippi River Basin. Increasing the production of the fertilizer-intensive crop will make it even more difficult to goal of shrinking the nitrogen-fuelled “dead zone” in the Gulf of Mexico.
To meet the 2012 ethanol goal, corn production is bound to increase [the only other option is to meet the goal purely by diverting corn grain away from feed or exports – not impossible, but less likely given the financial incentive to expand production]. That will require either the conversion of existing croplands to corn or the cultivation of existing croplands to corn.
The total area of croplands is unlikely to change significantly – it hasn’t in the past century. The best croplands were identified long ago. The change over the century has been in what crops are grown on those lands. Right now, around 2/3s to 3/4s of US croplands are devoted to just three crops: corn, soybeans and wheat.
So the thought it is that the extra corn production will come either at the expense of some other crop or at the expense of croplands currently left uncultivated. Some at the meeting suggested that farmers will replace soybeans with corn. Others, myself included, dismiss that notion: soybeans have been expanding for fifty years in the US and are too valuable crop to abandon (for ecological and economic reasons). It is more likely that either land devoted to other crops or lands contained within US Conservation Reserve Program – essentially farms are paid to leave some croplands fallow – will be used to expand corn production. Unless there is a major change in the production practices, the addition of more corn cultivation does not bode well for the nitrogen cycle.
The one reasonable argument for expanding corn-based ethanol production is that creating a market for biofuels will spur research on more efficient fuels. Thanks to market forces, corn-based ethanol may pave the way for a sensible form of biofuel production: either the “cellulosic” ethanol from high yielding grasses like switchgrass (that require no fertilizer) or biodiesel from oil-crops like soybeans, rapeseed or canola. If so, let’s hope the transition does not take too long.
