Simulation shows geoengineering is very risky
In the IPCC's latest report on ways to mitigate climate change, a compromise was reached that said: "Geo-engineering options, such as ocean fertilization to remove CO2 directly from the atmosphere, or blocking sunlight by bringing material into the upper atmosphere, remain largely speculative and unproven, and with the risk of unknown side-effects. Reliable cost estimates for these options have not been published".
A new computer modeling study now confirms these risks: radical steps to engineer Earth's climate by blocking sunlight could drastically cool the planet, but could just as easily worsen the situation if these projects fail or are suddenly halted. The researchers produced the study in the context of "dangerous climate change" that would require urgent and planet-wide interventions.
The experiments, described in an open access article in the June 4 early online edition of the Proceedings of the National Academy of Sciences, look at what might happen if we attempt to slow climate change by geoengineering a solar filter instead of reducing carbon dioxide emissions. The researchers used a computer model to simulate a decrease in solar radiation across the entire planet, but assumed that that the current trend of increasing global carbon dioxide emissions would continue for the rest of this century.
According to other researchers, if abrupt climate change were to occur, a lower risk geoengineering option exists that does not rely on blocking sunlight. Reducing carbon dioxide emissions on a planetary scale may be successful by investing in biomass and sequestration of carbon in soils or special geological formations. This type of low-risk geoengineering can be implemented via carbon-negative bioenergy systems (earlier post, and here, here and on capturing carbon via real trees versus synthetic trees, here).
So what did the simulation model for sun-blocking geoengineering options reveal? It showed that even after greenhouse gases warm the planet, geoengineering schemes could indeed cool off the Earth within a few decades to temperatures not seen since the dawn of the industrial revolution. This is good news, according to Caldeira and lead author Damon Matthews of Concordia University in Montreal, Canada, because it suggests there is no need to rush into building a geoengineering system before it is absolutely necessary.
However, the study also offers some bad news. If any hypothetical geoengineering program were to fail or be cancelled for any reason, a catastrophic, decade-long spike in global temperatures could result, along with rates of warming 20 times greater than we are experiencing today:
bioenergy :: biofuels :: energy :: sustainability :: climate change :: global cooling :: geoengineering :: greenhouse gas emissions :: biomass ::
"If we become addicted to a planetary sunshade, we could experience a painful withdrawal if our fix was suddenly cut off," Caldeira explained. "This needs to be taken into consideration if we ever think seriously about implementing a geoengineering strategy."
Caldeira and Matthews believe that lower temperatures in a geoengineered world would result in more efficient storage of carbon in plants and soils. However, if the geoengineering system failed and temperatures suddenly increased, much of that stored carbon would be released back into the atmosphere. This, in turn, could lead to accelerated greenhouse warming.
Reduced solar radiation not only affects temperatures in the simulations, but also global rainfall patterns. In a model run with no simulated geoengineering, warmer temperatures resulted in more rainfall over the oceans, while increased carbon dioxide levels caused a decrease in evaporation from plants' leaves, and consequently a decrease in rainfall over tropical forests. In contrast, the geoengineering scenario - which had lower temperatures but the same high levels of carbon dioxide - resulted only in a decrease in tropical forest rainfall.
"Many people argue that we need to prevent climate change. Others argue that we need to keep emitting greenhouse gases," Caldeira said. "Geoengineering schemes have been proposed as a cheap fix that could let us have our cake and eat it, too. But geoengineering schemes are not well understood. Our study shows that planet-sized geoengineering means planet-sized risks."
Caldeira feels it is important to develop a scientific understanding of proposed geoengineering schemes: "I hope I never need a parachute, but if my plane is going down in flames, I sure hope I have a parachute handy," Caldeira said. "I hope we'll never need geoengineering schemes, but if a climate catastrophe occurs, I sure hope we will have thought through our options carefully."
More information:
H. Damon Matthews and Ken Caldeira, "Transient climate-carbon simulations of planetary geoengineering", Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0700419104, Published online before print June 4, 2007
Article continues
A new computer modeling study now confirms these risks: radical steps to engineer Earth's climate by blocking sunlight could drastically cool the planet, but could just as easily worsen the situation if these projects fail or are suddenly halted. The researchers produced the study in the context of "dangerous climate change" that would require urgent and planet-wide interventions.
The experiments, described in an open access article in the June 4 early online edition of the Proceedings of the National Academy of Sciences, look at what might happen if we attempt to slow climate change by geoengineering a solar filter instead of reducing carbon dioxide emissions. The researchers used a computer model to simulate a decrease in solar radiation across the entire planet, but assumed that that the current trend of increasing global carbon dioxide emissions would continue for the rest of this century.
"Given current political and economic trends, it is easy to become pessimistic about the prospect that needed cuts in carbon dioxide emissions will come soon enough or be deep enough to avoid irreversibly damaging our climate. If we want to consider more dramatic options, such as deliberately altering the Earth's climate, it's important to understand how these strategies might play out." - co-author, Ken Caldeira, Department of Global Ecology, Carnegie InstitutionAlthough the term 'geoengineering' describes any measure intended to modify the Earth at the planetary scale, the current study focuses on changes that reduce the amount of solar radiation that reaches the planet's surface. Several methods to accomplish this have been suggested, from filling the upper atmosphere with light-reflecting sulfate particles to installing mirrors in orbit around the planet (earlier post).
According to other researchers, if abrupt climate change were to occur, a lower risk geoengineering option exists that does not rely on blocking sunlight. Reducing carbon dioxide emissions on a planetary scale may be successful by investing in biomass and sequestration of carbon in soils or special geological formations. This type of low-risk geoengineering can be implemented via carbon-negative bioenergy systems (earlier post, and here, here and on capturing carbon via real trees versus synthetic trees, here).
So what did the simulation model for sun-blocking geoengineering options reveal? It showed that even after greenhouse gases warm the planet, geoengineering schemes could indeed cool off the Earth within a few decades to temperatures not seen since the dawn of the industrial revolution. This is good news, according to Caldeira and lead author Damon Matthews of Concordia University in Montreal, Canada, because it suggests there is no need to rush into building a geoengineering system before it is absolutely necessary.
However, the study also offers some bad news. If any hypothetical geoengineering program were to fail or be cancelled for any reason, a catastrophic, decade-long spike in global temperatures could result, along with rates of warming 20 times greater than we are experiencing today:
bioenergy :: biofuels :: energy :: sustainability :: climate change :: global cooling :: geoengineering :: greenhouse gas emissions :: biomass ::
"If we become addicted to a planetary sunshade, we could experience a painful withdrawal if our fix was suddenly cut off," Caldeira explained. "This needs to be taken into consideration if we ever think seriously about implementing a geoengineering strategy."
Caldeira and Matthews believe that lower temperatures in a geoengineered world would result in more efficient storage of carbon in plants and soils. However, if the geoengineering system failed and temperatures suddenly increased, much of that stored carbon would be released back into the atmosphere. This, in turn, could lead to accelerated greenhouse warming.
Reduced solar radiation not only affects temperatures in the simulations, but also global rainfall patterns. In a model run with no simulated geoengineering, warmer temperatures resulted in more rainfall over the oceans, while increased carbon dioxide levels caused a decrease in evaporation from plants' leaves, and consequently a decrease in rainfall over tropical forests. In contrast, the geoengineering scenario - which had lower temperatures but the same high levels of carbon dioxide - resulted only in a decrease in tropical forest rainfall.
"Many people argue that we need to prevent climate change. Others argue that we need to keep emitting greenhouse gases," Caldeira said. "Geoengineering schemes have been proposed as a cheap fix that could let us have our cake and eat it, too. But geoengineering schemes are not well understood. Our study shows that planet-sized geoengineering means planet-sized risks."
Caldeira feels it is important to develop a scientific understanding of proposed geoengineering schemes: "I hope I never need a parachute, but if my plane is going down in flames, I sure hope I have a parachute handy," Caldeira said. "I hope we'll never need geoengineering schemes, but if a climate catastrophe occurs, I sure hope we will have thought through our options carefully."
More information:
H. Damon Matthews and Ken Caldeira, "Transient climate-carbon simulations of planetary geoengineering", Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0700419104, Published online before print June 4, 2007
Article continues
Tuesday, June 05, 2007
British project: bioenergy to boost food, income and energy security amongst poor in arid India
The £859,193 (€1.3/US$1.7 million) project is funded by the Engineering & Physical Sciences Research Council (EPSRC) and could improve the living conditions of many Indian people as well as having long-term benefits to academic research.
Dr Philip Davies and Dr Jason Hill from Aston will begin work on the project in June and it will last for 36 months. They will join colleagues from the universities of Warwick, Leeds, Bristol and Coventry with assistance from WRc (previously called the Water Research Centre) and in close collaboration with the Indian Institute of Technology in Delhi.
The project demonstrates many of the points made by the Biopact, namely that biofuel production can boost the food and income security of the world's poor, reduce internal migration and poverty, and restore and protect the environment.
The specific objectives of the project are:
- To implement plantations for energy and other useful produce in village communities where the groundwater is brackish, with the assistance of combined solar stills and rainwater harvesters.
- To investigate the feasibility and optimum method of combining secondary or tertiary sewage treatment with energy crop plantations (ie. 'fertigation').
- To develop tri-generation systems in which small-scale biomass-powered electricity generators are integrated with ice-making machines and low-temperature thermal applications such as crop drying and water purification.
- To produce quantitative models of the energy systems, thus enabling prediction of their probable performance according to location and scale. This will include the use of soft-systems modelling i.e. taking into account the inherent uncertainties generated by the interaction of people, agriculture and climate.
- To determine the factors affecting the success of such technological interventions, from a socio-economic viewpoint.
Bioenergy boost to food securityThe overall aim of the consortium is to provide improved means of cultivating biomass resources in water-scarce areas of Northern India and of locally converting them into useful energy services such as cooling for food preservation and ice production, electricity and applications using low-temperature heat such as food processing. There will be a high emphasis on the teaching of practical skills to local people.
Biomass production requires water and land which are also needed for other purposes. The project's approach therefore is to introduce technologies having multiple benefits. The engineers will set up a plantation in the village of Manpura (which is an isolated community in Rajasthan) to grow crops which can yield not only energy but also food, fodder, soap and botanical pesticides:
bioenergy :: biofuels :: energy :: sustainability :: energy crops :: biomass :: water :: poverty alleviation :: arid :: India ::
In Faridabad (which is a small town in Haryana state) they will grow energy crops and at the same time treat sewage. A small scale tri-generation system, fuelled by biomass, will be developed to provide electricity, ice for food preservation, heat for drying crops and/or pure water for drinking.
Strengthening local livelihoods
The lack of basic services requiring energy and water contributes to the pressures on rural people in India to abandon their way of life and join the drift towards the country’s growing cities.
"Often they end up living in slum conditions on the edge of escalating property markets, leaving behind them a kind of rural wasteland", continued Dr Davies. "We would like to counter this trend by setting up models of livelihood and local enterprise based on sustainable land use coupled with technology for the local provision of energy and related services."
A key element of the work will be the identification of socio-economic success factors in the project through interviews, focus groups and observations in India, facilitated by the partners at IIT-Delhi.
‘This socio-economic study will measure the project’s success in the areas where it has been implemented. We will also carry out modelling, taking into account both the physical systems (for example engines or refrigerators) and the human participants. This modelling will enable us to investigate a variety of future scenarios in which the technologies could be introduced."
Professor Julia King, Vice-Chancellor of Aston University, said: "Aston’s involvement in this project is another excellent example of how our researchers’ engineering knowledge base is being translated into practical solutions for improving people’s lives. I am delighted that the University is involved and look forward to receiving news of the project’s progress."
ICRISAT's pro-poor biofuels
The British project resembles that of the pro-poor biofuels initiative by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), which is also linking up poor and marginal farmers of the drylands of the developing countries with the global biofuel revolution while strengthening their food and income security.
The Andhra-Pradesh based scientific institute, which is a partner of the Consultative Group on International Agricultural Research (CGIAR) that helped achieve the 'Green Revolution', is working with governments and industry leaders to develop partnerships that can result in economic benefits for the poor and marginal farmers of the semi-arid tropics, even while retaining the strong economic competitiveness for the industry. The idea is to develop partnerships that link ICRISAT's innovative research directly with farmers and markets.
Under the pro-poor biofuels initiative, ethanol will be made from a high-yield sweet sorghum variety developed by the ICRISAT and that smallholders in drylands can cultivate with ease. The crop yields food, fodder and fuel. Likewise, cooperatives run by women make biodiesel from crops such as jatropha and pongamia and use the fuel to power diesel generators for rural electrification, tractors and farming equipment, with positive effects on farm productivity.
More information:
Aston University: Aston’s expertise helps develop energy solutions for India - June 5, 2007.
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posted by Biopact team at 5:10 PM 1 comments links to this post