Recent ground-based observations of auroral radio waves have identified narrowband emissions near 2 and 3 times the lower ionospheric electron cyclotron frequency (fce) known as auroral roars. In this paper the propagation of these waves in the auroral ionosphere is investigated by means of a ray-tracing technique. We model one particular scenario in which a large-scale (tens of kilometers) hor...

In the 2009 Copenhagen Accord, China agreed to slash its carbon intensity (carbon dioxide emissions/GDP) by 40% to 45% from the 2005 level by 2020. We assess whether China can achieve the target under the business-as-usual scenario by forecasting its emissions from energy consumption. Our preferred model shows that China’s carbon intensity is projected to decline by only 33%. The results imply ...

This paper presents a systematic scenario analysis of how different levels of short-term 2020 emissions would impact the technological and economic feasibility of achieving the 2 C target in the long term. We find that although a relatively wide range of emissions in 2020—from 41 to 55 billion tons of carbon dioxide equivalent (Gt CO2e yr−1)—may preserve the option of meeting a 2 C target, the ...

This paper summarizes the results of a studyFScenarios for a Clean Energy FutureFthat assess how energy-efficient and clean energy technologies can address key energy and environmental challenges facing the US. A particular focus of this study is the energy, environmental, and economic impacts of different public policies and programs. Hundreds of technologies and approximately 50 policies are ...

With the enactment of a new federal transportation law in 2005, State and regional transportation plans and programs are for the first time required to achieve the objectives of the SAFETEA-LU planning process, which focus on enhancing mobility and supporting economic development, while minimizing conventional emissions and greenhouse gas emissions. In 2007, the U.S. Supreme Court held that gre...

In 2012 Brazil's National Congress altered the country's Forest Code, decreasing various environmental protections in the set of regulations governing forests. This suggests consequences in increased deforestation and emissions of greenhouse gases and in decreased protection of fragile ecosystems. To ascertain the effects, a simulation was run to the year 2025 for the municipality (county) of B...

China has pledged to reduce its CO2 emissions per unit of GDP by 40–45% by 2020 as of 2005 level. This research examines China’s 2020 carbon intensity target and its interdependence with the overarching national economic and social development goals. The results show that, with annual GDP growth rate at 7% during the 12th Five-Year-Plan (FYP) period and 6% during the 13th FYP period, the 45% CO...

Current trends in transport indicate that the system is moving away from sustainability and that major changes are necessary to make the transport system more compatible with environmental sustainability. Main problems may occur in urban transport, where not many promising solutions are expected, while the problems are severe. In view of the great number of uncertainties, we will in our paper r...

BACKGROUND There is an established U-shaped association between daily temperature and mortality. Temperature changes projected through the end of century are expected to lead to higher rates of heat-related mortality but also lower rates of cold-related mortality, such that the net change in temperature-related mortality will depend on location. OBJECTIVES We quantified the change in heat-, c...

Large uncertainties exist in our knowledge of regional emissions of non-methane biogenic volatile organic compounds (BVOC). We address these uncertainties through a two-pronged approach by compiling a state of the art database of the emissions potentials for 80 European forest species, and by a model assessment and inter-comparison, both at the local and regional scale, under present and projec...