Climate risks of bioenergy underestimated

Joint press release by Technische Universität Berlin and Potsdam Institute for Climate Impact Research


 Climate risks of bioenergy underestimated

Energy from biomass presents underappreciated risks, new research published in Nature Climate Change shows. “A precautionary approach is needed,” says Ottmar Edenhofer, chief economist of the Potsdam Institute for Climate Impact Research (PIK) and professor at the Technische Universität Berlin (TU Berlin). “Before further expanding bioenergy, science has to deliver a more comprehensive risk assessment to policy makers – dealing with the uncertainties inherent to projections of bioenergy use up to now. Novel kinds of risk management for land-use change are needed.” One option would be to shift the burden-of-proof of meeting sustainability standards to the bioenergy producers.

 Large-scale cultivation of bioenergy crops could lead to increased net greenhouse-gas emissions when, for instance, forests are cleared for agricultural use. At the same time, long-term scenarios suggest that replacing fossil fuels to achieve low CO2 stabilisation might require major deployment of bioenergy. The article provides a framework for reconciling these two seemingly disparate views and identifies key uncertainties underlying the debate.

„Bioenergy is a matter of heated debate,“ says Felix Creutzig, lead author of the article by scientists from TU Berlin, PIK, and the University of California in Berkeley. „Scientists need to be very clear about the assumptions that their analyses rest upon and the effect alternative assumptions may have on their conclusions when they aim to systematically explore the risks associated with alternative policy options. Policy makers may choose to only allow further bioenergy deployment under very restricted circumstances.“

The net effect on climate of increasing production of bioenergy is highly uncertain. While current analyses are mostly good at accounting for historical emissions in the production of energy from biomass, according to the study the effects of future large-scale deployment of biofuels on agricultural and transportation fuel markets are often ignored. For instance, increased biofuels feedstock production on agricultural land might drive global food prices up. This provides significant incentives to expand agricultural area at the expense of natural carbon sinks.

In contrast, many economic climate change mitigation scenarios treat bioenergy as “carbon neutral” by assuming the implementation of policies to prevent deforestation and that technological progress will enable increased bioenergy yields per hectare. Whether these assumptions will prove correct is difficult to predict, and differing beliefs about such assumptions cause estimates of bioenergy potential to vary substantially – that is, by a factor of ten.

Comprehensive assessments of the climate benefits of bioenergy should try to explore the full range of possible outcomes and systematically integrate market effects, the researchers conclude.  This also includes more systematic assessments of the climate performance of bioenergy in imperfect worlds with, for example, limited technological progress or policies. Progress in this debate will require much greater interdisciplinary collaboration and coordination among researchers across the numerous scientific communities touched by bioenergy.

„This is one key challenge for upcoming scientific assessments,” Edenhofer points out. “Projections of bioenergy use partially depend on value judgements – concerning energy security, climate change mitigation, food security, and biodiversity protection.“ When science succeeds in communicating all underlying assumptions and uncertainties to policy-makers, says Edenhofer, „then that can be a starting point for the important discussion on where we as a society want to go and which risks we are willing to take.”

The analysis has been supported by the Michael Otto Stiftung and the German Federal Ministry of Education and Research.

Article: Creutzig, F., Popp, A., Plevin, R., Luderer, G., Minx, J., Edenhofer, O. (Nature Climate Change, 2012): Reconciling top-down and bottom-up modelling on future bioenergy deployment [doi:10.1038/nclimate1416]

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1 Response

  1. Poo says:

    Planet Earth has survived approximately 11 Ice Ages during its lifetime. That would leave some 12 periods of warming, make that global warming, over the same period. In Canada we would call that 8 months of winter and 4 months of bad sledding. While there is little doubt that man has contributed somewhat to recent warming trends, we contributed little or nothing to the previous periods. They happened quite naturally. Climate is like that. The difference today is that man, in his arrogance, thinks he is in control. I am reminded of Stephen Crane’s wee poem: “A warrior stood upon a peak and defied the stars. A little magpie, happening there, desired the soldier’s plume and so plucked it.” And yet we shake our fists at the Environment. My advice is don’t wear plumes if you do.

    Personally, I have always been a Sun man having been naturally warmed by it in my lifetime more than anything esle this side of a well stoked fireplace on a winter’s night. The following article is about the Sun. It is rather good and agree or not, worth a read.

    Lorne Gunter: For climate cues, look to the sun
    National Post, Mar 7, 2012.

    Ottawa’s giant skating rink on the Rideau Canal was closed in February due to thin ice caused by unseasonably mild temperatures. Yet, at the same time, ice blocked the canals of Venice for the first time in recent memory as temperatures in the exquisite Italian city dropped to -10C for more than a week. In the Netherlands, canals were closed to commercial boat traffic because ice made them unnavigable — another unusual development.

    Also in early February, fountains in southern France froze over. Polish rail lines were chocked with metres of snow. Swiss villages were cut off by record accumulations this winter. In Japan, tens of thousands of residents were confined to their homes because there was too little removal equipment to clear all the white stuff. At one point three weeks ago, more than 140,000 people worldwide were reportedly stranded by snow.

    So which is likely to be the new norm: North America’s mild winter, or Europe’s and Asia’s cold, snowy season?

    To hear climate alarmists and environmentalists tell it, the world will soon be without winter. There will be no more backyard skating rinks or Arctic sea ice to sustain the polar bears. Snow will become a rarity in much of Europe, and tornados such as the ones that devastated large swaths of the American Midwest last weekend will become more commonplace.

    But that’s not what some solar physicists are predicting.

    Scientists who have made careers of studying the sun warn that our star is about to enter a less-active phase — a solar minimum that could last 30 years or longer. If that happens, some physicists see a worldwide return to the temperatures of the Little Ice Age (LIA). Not coincidentally, the deepest part of the LIA — during the late 17th century — was the last time our sun generated as few sunspots and as little geomagnetic activity as it appears set to generate for the next few decades.

    Solid records of the connection between solar activity and Earth’s temperatures go back at least 300 years. If so-called proxy records are included — evidence from tree rings and ice-core samples, for instance — then the connection is thousands of years old.

    The sun-temperature connection only makes sense. Which is warmer, summer or winter? Daytime or night? A sunny day or a cloudy one?

    Sometimes I wonder whether our Neolithic ancestors understood better than modern climate alarmists what warmed the Earth. They didn’t build monuments that marked the summer and winter solstices because they worried the soot from their cooking fires was dangerously warming the planet. They built Stonehenge and the Goseck Circle and others to ensure the declining sun of winter would come back and prompt the return of spring and the plants and animals they relied on for their subsistence.

    For years, now, the global-warming establishment has tried to minimize the effects the sun has on weather and climate. For instance, rough drafts of the UN’s next five-year report on climate change (which are already circulating) apparently devote just a single sentence to the sun’s role as a “driver” of temperatures on Earth, while page after page after page obsesses on the carbon-dioxide-temperature theory.

    The fact is, scientists have studied the sun so thoroughly for so long that they can forecast with about 85% confidence what will happen to our temperatures if the number of sunspots rises or lowers from one cycle to the next and if the sun’s geomagnetic activity strengthens or weakens. They even know the effect on temperatures if one solar cycle — typically about 11 years — is longer or shorter than the cycle before it. And by studying the forces at work deep inside the sun, they can estimate with accuracy the length of the next cycle or two. This gives them a good idea of the sun’s influence on climate for the next few decades.

    According to a recent study by three Norwegian scientists — Jan-Erik Solheim, Kjell Stordahl and Ole Humlum — the sun’s current cycle has lasted so long that the next, due to begin any time now, will see a decline in temperatures of 0.63C. And that cycle is expected to last so long that the cycle after that will witness a temperature drop of 0.95C.

    Given that the planet has warmed only about 0.7C or 0.8C over the past century, that means all the warming Earth has experienced since 1900 could be wiped out in the next solar cycle, and in the cycle after that temperatures could retreat to levels not seen since the 18th century.

    Start idling your full-sized SUVs in your driveways now. The planet may need all the global warming it can get.

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