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Citizen Involvement in the U.S. Endangered Species Act
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Data on listed species refute critiques of citizen involvement in the U.S. Endangered Species Act.
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Elevated Eocene Atmospheric CO2 and Its Subsequent Decline
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Closing paragraph: Estimates of early Eocene atmospheric CO2 from Green River sodium carbonates are in the same range as those predicted by geochemical models (7). By È20 Ma, all available data (8) suggest ECO2^atm was at or near modern concentrations.
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The False Spring of 2012, Earliest in North American Record
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2nd paragraph: As global climate warms, increasingly warmer springs may combine with the random climatological occurrence of advective freezes, which result from cold air moving from one region to another, to dramatically increase the future risk of false springs, with profound ecological and economic consequences [e.g., Gu et al., 2008; Marino et al., 2011; Augspurger, 2013]. For example, in the false spring of 2012, an event embedded in long-term trends toward earlier spring [e.g., Schwartz et al., 2006], the frost damage to fruit trees totaled half a billion dollars in Michigan alone, prompting the federal government to declare the state a disaster area [Knudson, 2012].
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The Latest on Volcanic Eruptions and Climate
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2nd paragraph: It is well known that large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with a life- time of several months to about 2 years. The radiative effects of these aerosol clouds produce global cooling and are an important natural cause of climate change. Regional responses include winter warming of Northern Hemisphere continents and weakening of summer Asian and African monsoons. Even though there has not been a large eruption since the eruption of Mount Pinatubo in the Philippines on 15 June 1991, research contin- ues to produce interesting results.
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EPA and the Army Corps’ Proposed Rule to Define “Waters of the United States”
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Excerpt from summary : According to the agencies, the proposed rule would revise the existing regulatory definition of “waters of the United States” consistent with legal rulings—especially the Supreme Court cases—and science concerning the interconnectedness of tributaries, wetlands, and other waters to downstream waters and effects of these connections on the chemical, physical, and biological integrity of downstream waters. Waters that are “jurisdictional” are subject to the multiple regulatory requirements of the CWA: standards, discharge limitations, permits, and enforcement. Non-jurisdictional waters, in contrast, do not have the federal legal protection of those requirements.
This report describes the March 25 proposed rule and includes a table comparing the existing regulatory language that defines “waters of the United States” with that in the proposal.
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Bias in the attribution of forest carbon sinks
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A substantial fraction of the terrestrial carbon sink, past and present, may be incorrectly attributed to environmental change rather than changes in forest management.
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Sectoral contributions to surface water stress in the coterminous United States
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Here, we assess current stress in the freshwater system based on the best available data in order to understand possible risks and vulnerabilities to regional water resources and the sectors dependent on freshwater. We present watershed-scale measures of surface water supply stress for the coterminous United States (US) using the water supply stress index (WaSSI) model which considers regional trends in both water supply and demand. A snapshot of contemporary annual water demand is compared against different water supply regimes, including current average supplies, current extreme-year supplies, and projected future average surface water flows under a changing climate. In addition, we investigate the contributions of different water demand sectors to current water stress. On average, water supplies are stressed, meaning that demands for water outstrip natural supplies in over 9% of the 2103 watersheds examined. These watersheds rely on reservoir storage, conveyance systems, and groundwater to meet current water demands. Overall, agriculture is the major demand-side driver of water stress in the US, whereas municipal stress is isolated to southern California. Water stress introduced by cooling water demands for power plants is punctuated across the US, indicating that a single power plant has the potential to stress water supplies at the watershed scale. On the supply side, watersheds in the western US are particularly sensitive to low flow events and projected long-term shifts in flow driven by climate change. The WaSSI results imply that not only are water resources in the southwest in particular at risk, but that there are also potential vulnerabilities to specific sectors, even in the ‘water-rich’ southeast.
Keywords: water resources, surface water, water stress
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Rethinking wedges
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Stabilizing CO2 emissions at current levels for fifty years is not consistent with either an atmospheric CO2 concentration below 500 ppm or global temperature increases below 2 ◦C. Accepting these targets, solving the climate problem requires that emissions peak and decline in the next few decades, and ultimately fall to near zero. Phasing out emissions over 50 years could be achieved by deploying on the order of 19 ‘wedges’, each of which ramps up linearly over a period of 50 years to ultimately avoid 1 GtC y−1 of CO2 emissions. But this level of mitigation will require affordable carbon-free energy systems to be deployed at the scale of tens of terawatts. Any hope for such fundamental and disruptive transformation of the global energy system depends upon coordinated efforts to innovate, plan, and deploy new transportation and energy systems that can provide affordable energy at this scale without emitting CO2 to the atmosphere.
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Linking primary production, climate and land use along an urban–wildland transect: a satellite view
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Variation of green vegetation cover influences local climate dynamics, exchange of water–heat between land and atmosphere, and hydrological processes. However, the mechanism of interaction between vegetation and local climate change in subtropical areas under climate warming and anthropogenic disturbances is poorly understood. We analyzed spatial–temporal trends of vegetation with moderate-resolution imaging spectroradiometer (MODIS) vegetation index datasets over three sections, namely urban, urban–rural fringe and wildland along an urban–wildland transect in a southern mega-city area in China from 2000–2008. The results show increased photosynthetic activity occurred in the wildland and the stable urban landscape in correspondence to the rising temperature, and a considerable decrease of vegetation activity in the urban–rural fringe area, apparently due to urban expansion. On analyzing the controlling factors of climate change and human drivers of vegetation cover change, we found that temperature contributed to vegetation growth more than precipitation and that rising temperature accelerated plant physiological activity. Meanwhile, human-induced dramatic modification of land cover, e.g. conversion of natural forest and cropland to built-up areas in the urban–rural fringe, has caused significant changes of green vegetation fraction and overall primary production, which may further influence local climate.
Keywords: vegetation greenness, environmental gradients, urban, transect, climate change, remote sensing, rural
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Energy intensities, EROIs (energy returned on invested), and energy payback times of electricity generating power plants
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The energy returned on investment, EROI, has been evaluated for typical power plants representing wind energy, photovoltaics, solar thermal, hydro, natural gas, biogas, coal and nuclear power. The strict exergy concept with no “primary energy weighting”, updated material databases, and updated technical pro- cedures make it possible to directly compare the overall efficiency of those power plants on a uniform mathematical and physical basis. Pump storage systems, needed for solar and wind energy, have been included in the EROI so that the efficiency can be compared with an “unbuffered” scenario. The results show that nuclear, hydro, coal, and natural gas power systems (in this order) are one order of magnitude more effective than photovoltaics and wind power
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