It's Warm Outside
Climate Sensitivity Estimated from Temperature Reconstructions of the Last Glacial Maximum
Andreas Schmittner et al.
Science, 9 December 2011, Pages 1385-1388
Abstract:
Assessing impacts of future anthropogenic carbon emissions is currently impeded by uncertainties in our knowledge of equilibrium climate sensitivity to atmospheric carbon dioxide doubling. Previous studies suggest 3 K as best estimate, 2 to 4.5 K as the 66% probability range, and nonzero probabilities for much higher values, the latter implying a small but significant chance of high-impact climate changes that would be difficult to avoid. Here, combining extensive sea and land surface temperature reconstructions from the Last Glacial Maximum with climate model simulations, we estimate a lower median (2.3 K) and reduced uncertainty (1.7 to 2.6 K 66% probability). Assuming paleoclimatic constraints apply to the future as predicted by our model, these results imply lower probability of imminent extreme climatic change than previously thought.
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Rapid growth in CO2 emissions after the 2008-2009 global financial crisis
Glen Peters et al.
Nature Climate Change, January 2012, Pages 2-4
Abstract:
Global carbon dioxide emissions from fossil-fuel combustion and cement production grew 5.9% in 2010, surpassed 9 Pg of carbon (Pg C) for the first time, and more than offset the 1.4% decrease in 2009. The impact of the 2008-2009 global financial crisis (GFC) on emissions has been short-lived owing to strong emissions growth in emerging economies, a return to emissions growth in developed economies, and an increase in the fossil-fuel intensity of the world economy.
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Lucas Davis
NBER Working Paper, December 2011
Abstract:
The prospects for a revival of nuclear power were dim even before the partial reactor meltdowns at the Fukushima nuclear plant. Nuclear power has long been controversial because of concerns about nuclear accidents, proliferation risk, and the storage of spent fuel. These concerns are real and important. In addition, however, a key challenge for nuclear power has been the high cost of construction for nuclear plants. Construction costs are high enough that it becomes difficult to make an economic argument for nuclear, even before incorporating these external costs. This is particularly true in countries like the United States where recent technological advances have dramatically increased the availability of natural gas.
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The Technology Path to Deep Greenhouse Gas Emissions Cuts by 2050: The Pivotal Role of Electricity
James Williams et al.
Science, forthcoming
Abstract:
Reducing greenhouse gas emissions 80% below 1990 levels by 2050 is the subject of vigorous policy debate, but there has been little physically realistic modeling of the energy and economic transformations required. We analyzed the infrastructure and technology path required to meet this goal in a specific economy (California), using detailed modeling of infrastructure stocks, resource constraints, and electricity system operability. We find that technically feasible levels of energy efficiency and decarbonized energy supply alone are not sufficient. Rather, widespread electrification of transportation and other sectors is required. Decarbonized electricity becomes the dominant form of energy supply, posing challenges and opportunities for economic growth and climate policy. The transformation demands technologies that are not yet commercialized and coordination of investment, technology development, and infrastructure deployment.
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Safe storage and effective monitoring of CO2 in depleted gas fields
Charles Jenkins et al.
Proceedings of the National Academy of Sciences, forthcoming
Abstract:
Carbon capture and storage (CCS) is vital to reduce CO2 emissions to the atmosphere, potentially providing 20% of the needed reductions in global emissions. Research and demonstration projects are important to increase scientific understanding of CCS, and making processes and results widely available helps to reduce public concerns, which may otherwise block this technology. The Otway Project has provided verification of the underlying science of CO2 storage in a depleted gas field, and shows that the support of all stakeholders can be earned and retained. Quantitative verification of long-term storage has been demonstrated. A direct measurement of storage efficiency has been made, confirming that CO2 storage in depleted gas fields can be safe and effective, and that these structures could store globally significant amounts of CO2.
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Kyoto and the carbon footprint of nations
Rahel Aichele & Gabriel Felbermayr
Journal of Environmental Economics and Management, forthcoming
Abstract:
The carbon footprint of a country refers to the flow of CO2 emissions caused by domestic absorption (i.e., consumption and investment) activities. Trade in goods drives a wedge between the footprint and domestic emissions. We provide a new panel database on carbon footprints and carbon net trade. Using a first-differenced IV estimation strategy, we evaluate the effects of ratification of binding Kyoto commitments on the carbon footprint and emissions. Instrumenting countries' Kyoto commitment by their participation in the International Criminal Court, we show that Kyoto commitment has reduced domestic emissions in committed countries by about 7%, has not lowered carbon footprints, but has increased the share of imported over domestic emissions by about 14 percentage points. It follows that the Kyoto Protocol has had at best no effect on world-wide emissions. The results highlight the difficulties of unilateral climate policies.
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Rapid transgenerational acclimation of a tropical reef fish to climate change
J.M. Donelson et al.
Nature Climate Change, January 2012, Pages 30-32
Abstract:
Understanding the capacity of species to acclimate and adapt to expected temperature increases is critical for making predictions about the biological impacts of global warming, yet it is one of the least certain aspects of climate change science. Tropical species are considered to be especially sensitive to climate change because they live close to their thermal maximum and exhibit limited capacity for acclimation. Here, we demonstrate that a tropical reef fish is highly sensitive to small increases in water temperature, but can rapidly acclimate over multiple generations. Acute exposure to elevated temperatures (+1.5 °C and +3.0 °C) predicted to occur this century caused a 15% and 30% respective decrease in individual's maximum ability to perform aerobic activities such as swimming or foraging, known as aerobic scope. However, complete compensation in aerobic scope occurred when both parents and offspring were reared throughout their lives at elevated temperature. Such acclimation could reduce the impact of warming temperatures and allow populations to persist across their current range. This study reveals the importance of transgenerational acclimation as a mechanism for coping with rapid climate change and highlights that single generation studies risk underestimating the potential of species to cope.
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Christopher Knittel
American Economic Review, December 2011, Pages 3368-3399
Abstract:
This paper estimates the technological progress that has occurred since 1980 in the automobile industry and the trade-offs faced when choosing between fuel economy, weight, and engine power characteristics. The results suggest that if weight, horsepower, and torque were held at their 1980 levels, fuel economy could have increased by nearly 60 percent from 1980 to 2006. Once technological progress is considered, meeting the CAFE standards adopted in 2007 will require halting the trend in weight and engine power characteristics, but little more. In contrast, the standards recently announced by the new administration, while attainable, require nontrivial "downsizing."
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Economic and energetic analysis of capturing CO2 from ambient air
Kurt Zenz House et al.
Proceedings of the National Academy of Sciences, 20 December 2011, Pages 20428-20433
Abstract:
Capturing carbon dioxide from the atmosphere ("air capture") in an industrial process has been proposed as an option for stabilizing global CO2 concentrations. Published analyses suggest these air capture systems may cost a few hundred dollars per tonne of CO2, making it cost competitive with mainstream CO2 mitigation options like renewable energy, nuclear power, and carbon dioxide capture and storage from large CO2 emitting point sources. We investigate the thermodynamic efficiencies of commercial separation systems as well as trace gas removal systems to better understand and constrain the energy requirements and costs of these air capture systems. Our empirical analyses of operating commercial processes suggest that the energetic and financial costs of capturing CO2 from the air are likely to have been underestimated. Specifically, our analysis of existing gas separation systems suggests that, unless air capture significantly outperforms these systems, it is likely to require more than 400 kJ of work per mole of CO2, requiring it to be powered by CO2-neutral power sources in order to be CO2 negative. We estimate that total system costs of an air capture system will be on the order of $1,000 per tonne of CO2, based on experience with as-built large-scale trace gas removal systems.
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Unique genetic variation at a species' rear edge is under threat from global climate change
Jim Provan & Christine Maggs
Proceedings of the Royal Society: Biological Sciences, 7 January 2012, Pages 39-47
Abstract:
Global climate change is having a significant effect on the distributions of a wide variety of species, causing both range shifts and population extinctions. To date, however, no consensus has emerged on how these processes will affect the range-wide genetic diversity of impacted species. It has been suggested that species that recolonized from low-latitude refugia might harbour high levels of genetic variation in rear-edge populations, and that loss of these populations could cause a disproportionately large reduction in overall genetic diversity in such taxa. In the present study, we have examined the distribution of genetic diversity across the range of the seaweed Chondrus crispus, a species that has exhibited a northward shift in its southern limit in Europe over the last 40 years. Analysis of 19 populations from both sides of the North Atlantic using mitochondrial single nucleotide polymorphisms (SNPs), sequence data from two single-copy nuclear regions and allelic variation at eight microsatellite loci revealed unique genetic variation for all marker classes in the rear-edge populations in Iberia, but not in the rear-edge populations in North America. Palaeodistribution modelling and statistical testing of alternative phylogeographic scenarios indicate that the unique genetic diversity in Iberian populations is a result not only of persistence in the region during the last glacial maximum, but also because this refugium did not contribute substantially to the recolonization of Europe after the retreat of the ice. Consequently, loss of these rear-edge populations as a result of ongoing climate change will have a major effect on the overall genetic diversity of the species, particularly in Europe, and this could compromise the adaptive potential of the species as a whole in the face of future global warming.
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Climatic changes in western North America, 1950-2005
Evan Booth, James Byrne & Dan Johnson
International Journal of Climatology, forthcoming
Abstract:
The rate of climatic change over western North America (WNA) is quantified for 485 climate stations for the period 1950-2005. Additionally, six stations with quality long-term records were selected and analysed for the period 1906-2005. The indicators used were developed by the World Meteorological Organization (WMO) and the World Climate Research Program's Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI). From the 27 core indices, 4 temperature-based and 4 precipitation-based indicators were selected for in-depth analysis. The 8 million km2 study area is comprised of the 22 contiguous US states and 4 Canadian provinces west of the Mississippi River and Great Lakes. The results were divided into six general regions for interpretation and presentation. GIS interpolation of station-specific statistical output was completed to further aid in the identification of spatially coherent trends across WNA. Mean slopes were calculated over the whole study area, and by region, for each index, and then tested to determine if they were significantly different from zero. Results of the study show statistically significant historical climate trends across the study area. As expected in a region as geographically diverse as WNA, results differed between, and within, regions. Overall, temperature-based indicators showed a general warming trend over the entire study area, with the greatest increases along the North American Cordillera. The trends in precipitation-based indicators were more varied. General trends indicate moderately increasing precipitation volume and intensity over much of WNA. The strongest precipitation trends were found in areas with climate largely controlled by air masses originating over the Gulf of Mexico.
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Reduced early life growth and survival in a fish in direct response to increased carbon dioxide
Hannes Baumann, Stephanie Talmage & Christopher Gobler
Nature Climate Change, January 2012, Pages 38-41
Abstract:
Absorption of anthropogenic carbon dioxide by the world's oceans is causing mankind's ‘other CO2 problem', ocean acidification. Although this process will challenge marine organisms that synthesize calcareous exoskeletons or shells, it is unclear how it will affect internally calcifying organisms, such as marine fish. Adult fish tolerate short-term exposures to CO2 levels that exceed those predicted for the next 300 years (~2,000 ppm), but potential effects of increased CO2 on growth and survival during the early life stages of fish remain poorly understood. Here we show that the exposure of early life stages of a common estuarine fish (Menidia beryllina) to CO2 concentrations expected in the world's oceans later this century caused severely reduced survival and growth rates. When compared with present-day CO2 levels (~400 ppm), exposure of M. beryllina embryos to ~1,000 ppm until one week post-hatch reduced average survival and length by 74% and 18%, respectively. The egg stage was significantly more vulnerable to high CO2-induced mortality than the post-hatch larval stage. These findings challenge the belief that ocean acidification will not affect fish populations, because even small changes in early life survival can generate large fluctuations in adult-fish abundance.
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Misak Avetisyan et al.
Applied Economic Perspectives and Policy, Winter 2011, Pages 584-605
Abstract:
The taxation of Greenhouse Gases (GHG) represents an efficient means of achieving climate change mitigation, and this is often the starting point in any discussion of long run global GHG reduction. However, the direct effects of such a tax, or equivalently, an emissions trading scheme, will vary across countries and sectors according to the emissions intensity of the sector. We report, for the first time, estimates of such livestock emissions intensities for all regions of the world and decompose the intensities to understand the sources of regional variation. Our findings indicate that most of the variation is due to differences in the value of output per animal in different regions, which in turn is due to regional differences in output per animal (yield) and dollar per unit output (price). Animals with relatively low annual output values tend to be characterized by higher economic emissions intensities. We find this to be the case in many developing countries. Livestock activity in these high emissions intensity regions are hit especially hard by an emissions tax, resulting in disproportionate reductions in output and consumption in many regions already suffering from malnutrition.