Implications of "peak oil" for atmospheric CO2 and climate

Unconstrained CO2 emission from fossil fuel burning has been the dominant cause of observed anthropogenic global warming. The amounts of "proven" and potential fossil fuel reserves are uncertain and debated. Regardless of the true values, society has flexibility in the degree to which it chooses to exploit these reserves, especially unconventional fossil fuels and those located in extreme or pristine environments. If conventional oil production peaks within the next few decades, it may have a large effect on future atmospheric CO2 and climate change, depending upon subsequent energy choices. Assuming that proven oil and gas reserves do not greatly exceed estimates of the Energy Information Administration, and recent trends are toward lower estimates, we show that it is feasible to keep atmospheric CO2 from exceeding about 450 ppm by 2100, provided that emissions from coal, unconventional fossil fuels, and land use are constrained. Coal-fired power plants without sequestration must be phased out before mid-century to achieve this CO2 limit. It is also important to "stretch" conventional oil reserves via energy conservation and efficiency, thus averting strong pressures to extract liquid fuels from coal or unconventional fossil fuels while clean technologies are being developed for the era "beyond fossil fuels". We argue that a rising price on carbon emissions is needed to discourage conversion of the vast fossil resources into usable reserves, and to keep CO2 beneath the 450 ppm ceiling.Comment: (22 pages, 7 figures; final version accepted by Global Biogeochemical Cycles

Counteracting the climate effects of volcanic eruptions using short-lived greenhouse gases

A large volcanic eruption might constitute a climate emergency, significantly altering global temperature and precipitation for several years. Major future eruptions will occur, but their size or timing cannot be predicted. We show, for the first time, that it may be possible to counteract these climate effects through deliberate emissions of short-lived greenhouse gases, dampening the abrupt impact of an eruption. We estimate an emission pathway countering a hypothetical eruption 3 times the size of Mount Pinatubo in 1991. We use a global climate model to evaluate global and regional responses to the eruption, with and without counteremissions. We then raise practical, financial, and ethical questions related to such a strategy. Unlike the more commonly discussed geoengineering to mitigate warming from long-lived greenhouse gases, designed emissions to counter temporary cooling would not have the disadvantage of needing to be sustained over long periods. Nevertheless, implementation would still face significant challenges

Uncertainty and climate change policy

The paper consists of a summary of the main sources of uncertainty about climate change, and a discussion of the major implications for economic analysis and the formulation of climate policy. Uncertainty typically implies that the optimal policy is more risk-averse than otherwise, and therefore enhances the case for action to mitigate climate change

Tidal energy machines: A comparative life cycle assessment

Marine energy in the UK is currently undergoing a period of exponential growth in terms of development and implementation. The current installed tidal energy capacity of around 4MW is expected to rise to provide up to 20% of the UK’s electricity demand by 2050 [5]. With this in mind, there is a huge range of energy devices, all seemingly promoted by their developers as the best method of extracting power from the ocean. Embodied energy is an important aspect of any power producing device or process, and is used to describe the amount of energy required to begin and maintain the process of energy generation. Until a device or process has generated this amount of energy it cannot be said to be a net contributor of energy. This work used Life Cycle Assessment to study four tidal energy devices, representing a cross section of the existing designs, and compares their embodied energy and carbon dioxide emissions. In order to ensure a fair comparison, a hypothetical installation site is used, with conditions typical of those found at potential array installation sites in the UK. The designs studied include a multi-blade turbine, two three blade horizontal axis turbine machines, and an Archimedes’ screw device. These machines were chosen to represent a cross section of device, foundation, installation and operation designs. They have all been developed to prototype stage, meaning that actual manufacturing data is available. Embodied energy is considered over the entire lifetime of each device, beginning with extraction of raw materials. Energy use from fabrication, transport, installation, lifetime maintenance, end-of-life decommissioning and recycling are all calculated, and compared to the energy generation from each device at the test site. Finally, the embodied energy; CO2 intensity; and energy payback periods are compared to those of conventional power generating systems as well as other renewable energy sources. A range of data sources are used. Embodied energy of steel has been provided by the World Steel Association. Of the four devices studied, all were found to achieve CO2 and energy payback within the first 12 years of their lifetime, and exhibited CO2 intensity of between 18 and 35 gCO2/kWh. This compares favourably to many current energy sources, and is likely to fall as technology improves, array size increases and industry experience progresses

Impact of rising sea levels on Australian fur seals

Global warming is leading to many unprecedented changes in the ocean-climate system. Sea levels are rising at an increasing rate and are amplifying the impact of storm surges along coastlines. As variability in the timing and strength of storm surges has been shown to affect pup mortality in the Australian fur seal (Arctocephalus pusillus doriferus), there is a need to identify the potential impacts of increased sea level and storm surges on the breeding areas of this important marine predator in Bass Strait, south-eastern Australia. Using high-resolution aerial photography and topographic data, the present study assessed the impacts of future inundation levels on both current and potential breeding habitats at each colony. Inundation from storm surges, based on a predicted rise in sea level, was modeled at each colony from 2012 to 2100. As sea level increases, progressively less severe storm surge conditions will be required to exceed current inundation levels and, thus, have the potential for greater impacts on pup mortality at Australian fur seal colonies. The results of the present study indicate that by 2100, a 1-in-10 year storm will inundate more habitat on average than a present-day 1-in-100 year storm. The study highlights the site-specific nature of storm surge impacts, and in particular the importance of local colony topography and surrounding bathymetry with small, low-lying colonies impacted the most. An increased severity of storm surges will result in either an increase in pup mortality rates associated with storm surges, or the dispersal of individuals to higher ground and/or new colonies

Mean or green? Values, morality and environmental significant behavior.

In most cases, pro-environmental behavior does not maximize individual interests, but mainly benefits other people or the environment. We propose that although acting on the basis of egoistic considerations may result in pro-environmental behavior, altruistic and biospheric considerations provide the most stable basis for pro-environmental behavior. We present two strategies to promote stable pro-environmental behavior. The first way is increasing the saliency of altruistic and biospheric values in specific situations, thereby reducing the relative strength of egoistic values. The second way is making the often “anti-environmental” egoistic values compatible with “pro-environmental” altruistic and biospheric values. We explain these options and translate it to possible interventions, policy implications, and follow-up research to promote “green” behavior

Predicting the distributions of under-recorded Odonata using species distribution models

1. Absences in distributional data may result either from the true absence of a species or from a false absence due to lack of recording effort. I use general linear models (GLMs) and species distribution models (SDMs) to investigate this problem in North American Odonata and present a potential solution. 2. I use multi-model selection methods based on Akaike's information criterion to evaluate the ability of water-energy variables, human population density, and recording effort to explain patterns of odonate diversity in the USA and Canada using GLMs. Water-energy variables explain a large proportion of the variance in odonate diversity, but the residuals of these models are significantly related to recorder effort. 3. I then create SDMs for 176species that are found solely in the USA and Canada using model averaging of eight different methods. These give predictions of hypothetical true distributions of each of the 176species based on climate variables, which I compare with observed distributions to identify areas where potential under-recording may occur. 4. Under-recording appears to be highest in northern Canada, Alaska, and Quebec, as well as the interior of the USA. The proportion of predicted species that have been observed is related to recorder effort and population density. Maps for individual species have been made available online () to facilitate recording in the future. 5. This analysis has illustrated a problem with current odonate recording in the form of unbalanced recorder effort. However, the SDM approach also provides the solution, targeting recorder effort in such a way as to maximise returns from limited resources