Reductions in carbon intensity, C/E, the carbon emitted per unit of energy generated, reflect the degree to which societies decarbonize their energy sources. The long-term trend has been a shift from coal to oil to natural gas––hydrocarbons with decreasing C/H ratios emitting progressively less CO2 per joule. However, the increasing use of clean low-carbon fuels is not sustainable without somehow disposing of excess carbon because it opposes the trend in the abundance of fossil fuels, with coal resources being the most abundant followed by oil and gas. (more…)
The global cycling of carbon involves both biological and physical processes. Only the biological components are discussed here. Pl ...
The flux of carbon among terrestrial, aquatic, and atmospheric pools is at least partially controlled by photosynthetic process ...
It is of interest to examine potential sources of greenhouse gases sources or atmospheric CO2 by analysis of the global distrib ...
Climate change caused by the enhanced greenhouse effect is one of the most significant global environmental issues. Increased emiss ...
The global carbon cycle involves both biological and physical processes. Only the biological components are discussed here. Pla ...
Addressing global warming, however, is a highly complex and daunting endeavor. Many climate experts have urged the world to stabilize greenhouse gas concentrations in the atmosphere around 450 to 550 parts per million (ppm)—that is, no more than 450 to 550 units of greenhouse gases for every million units of air in the earth’s atmosphere. This approach, experts say, could keep average global temperatures at no more than 3.6° Fahrenheit (2° Celsius) above preindustrial levels, which could avoid some of the worst, irreversible consequences of climate change. (more…)
Although some scientists and critics still dispute that human caused greenhouse gases are causing climate change, the majority of s ...
Climate change caused by the enhanced greenhouse effect is one of the most significant global environmental issues. Increased emiss ...
Options for dealing with the threats of climate change include both adaptation to inevitable changes and mitigation, or lessening, ...
Scientists study Earth’s climate not just from observation but also from a theoretical perspective. Modern-day climate models succe ...
Earth’s climate is a complex system of interacting natural components. These components include the atmosphere, the ocean, and the ...

The European Automobile Manufacturers Association (ACEA) has offered, and the European Commission (EC) has accepted, a voluntary commitment to reduce the CO2 emissions from new light-duty passenger vehicles, with firm fleetwide targets of 140 g CO2 /km (B41 mpg for gasoline) by 2008, measured under the new European test cycle (Directives 93/116/EC and 99/100/EC). This represents approximately a 25% reduction from the 1995 average of 187 g/km (B30 mpg) on this cycle. The European cycle is likely to produce lower fuel economy ratings than the U.S. combined urban/ highway cycle, so the ‘‘U.S. equivalent’’ miles per gallon ratings of the year 2008 European fleet will likely be higher than 41 mpg if the targets are met. (more…)
Although the automotive industry is a vigorous sponsor of research and development in vehicle efficiency technology—worldwide, ...
Addressing global warming, however, is a highly complex and daunting endeavor. Many climate experts have urged the world to stabili ...
We know of no studies that have examined vehicle taxation incentives programs elsewhere in the world, but it seems likely that ...
A variety of information programs exist in the major automobile markets to assist potential purchasers of new cars in comparing fue ...
There are various and somewhat complementary reasons to foster the growth of renewable energy sources in Europe. A major incent ...