Recent years have seen a flurry of energy-efficient networking research. But does decreasing the energy used by the Internet actually save society much energy? To answer this question, we estimate the Internet’s energy consumption. We include embodied energy (emergy)—the energy required to construct the Internet—a quantity that has often been ignored in previous work. We find that while in absolute terms the Internet uses significant energy, this quantity is negligible when compared with society’s colossal energy use.

Recent increases in natural gas reserve estimates and advances in shale gas technology make natural gas a fuel with good prospects to serve a bridge to a low-carbon world. Russia is an important energy supplier as it holds the world largest natural gas reserves and it is the world’s largest exporter of natural gas. Energy was one of the driving forces of Russia’s recent economic recovery from the economic collapse of 1990s. These prospects have changed drastically with a global recession and the collapse of oil and gas prices from their peaks of 2008. An additional factor is an ongoing surge in a liquefied natural gas (LNG) capacity and a development of Central Asia’s and the Middle East gas supplies that can compete with Russian gas in its traditional (European) and potential (Asian) markets. To study the long-term prospects for Russian natural gas, we employ the MIT Emissions Prediction and Policy Analysis (EPPA) model, a computable general equilibrium model of the world economy. While we consider the updated reserve estimates for all world regions, in this paper we focus on the results for Russian natural gas trade. The role of natural gas is explored in the context of several policy assumptions: with no greenhouse gas mitigation policy and scenarios of emissions targets in developed countries. Scenarios where Europe takes on an even more restrictive target of 80

The relationship between oil and nuclear energy in the global energy scene over the past 50 years is analysed. The former nuclear–oil product competition in power generation and various end-use markets is found to have transformed into a complementary relationship. Current concerns associated with both energy sources and related technologies, including price volatility, supply security, geopolitical sensitivity, depletion alarms, and environmental pollution issues for oil, economic performance, operational safety, proliferation, terrorism, radioactive waste disposal, and the resulting public acceptance for nuclear are examined as determinants of their future roles in the world energy balance. An assessment of the long-term prospects for oil and nuclear energy is presented at the scale of a century to support further economic and energy policy analyses. It is the first in-depth study of global energy projections based on a comparative examination of longterm socio-economic scenarios and their coordinated quantifications by a set of integrated energy– economy models.

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International negotiations for an agreement to reduce the emission of greenhouse gases are unlikely to produce concrete and comprehensive policies for effective emission reductions in the near term, not least because the policy measures being considered are economically very costly to major industries in rich countries and are unlikely to prevent `leakage' through a re-location of carbon-intensive activities to poorer countries. An alternative or supplementary approach that is more likely to achieve carbon and methane emission reductions, and at the same time generate national and global economic benefits rather than costs, involves lowering coal subsidies and trade barriers. Past coal policies which encouraged excessive production of coal in a number of industrial countries and excessive coal consumption in numerous developing and transition economies are currently under review and in some cases are being reformed. This paper documents those distortions and outlines the circumstances ...

role of as an energy source The role of coal as an energy source Key Messages • Energy demand has grown strongly and will continue to increase, particularly in developing countries where energy is needed for economic growth and poverty alleviation. • All energy sources will be needed to satisfy that demand by providing a diverse and balanced supply mix. • Coal is vital for global energy security. It is abundantly available, affordable, reliable and easy and safe to transport. • In an energy hungry world the challenge for coal, as for other fossil fuels, is to further substantially reduce its greenhouse gas and other emissions, while continuing to make a major contribution to economic and social development and energy security. • Coal is part way down a technology pathway that has already delivered major

Fossil fuels supply about 85 % of the world’s primary energy, and future use would not appear limited by availability of reserves, especially of coal. Rather, future use of fossil fuels will likely be limited by controls on the emission of carbon dioxide into the atmosphere that are agreed to by the nations of the world. The increase in atmospheric CO2 over the past 200 years, mainly from fossil fuel combustion, is confidently thought to have increased global temperatures and induced other changes in Earth’s climate, with the prospect of much more severe consequences from projected future emissions. Limiting such changes in Earth’s climate would place major constraints on the combustion of fossil fuels and/or the emission of CO2 into the atmosphere. Developing effective and cost-effective strategies for limiting CO2 emissions requires the confident ability to project the changes in climate that would result from a given increase in atmospheric CO2. However, even the change in global mean surface temperature (GMST), the single most important index of climate change, that would result from a given increase in atmospheric CO2 remains uncertain to a factor of 2 or more, largely because of uncertainty in Earth’s climate sensitivity, the change in GMST per change in radiative flux. This uncertainty in climate sensitivity, which gives rise to a comparable uncertainty in the shared global resource of the amount of fossil fuel that can be burned consonant with a given increase in global mean surface temperature, greatly limits the

This paper develops a long run growth model for a major oil exporting economy and derives conditions under which oil revenues are likely to have a lasting impact. This approach contrasts with the standard literature on the "Dutch disease" and the "resource curse", which primarily focus on short run implications of a temporary resource discovery. Under certain regularity conditions and assuming a Cobb Douglas production function, it is shown that (log) oil exports enter the long run output equation with a coefficient equal to the share of capital. The long run theory is tested using a new quarterly data set on the Iranain economy over the period 1979Q1-2006Q4. Building an error correction specification in real output, real money balances, inflation, real exchange rate, oil exports, and foreign real output, the paper finds clear evidence for two long run relations: an output equation as predicted by the theory and a standard real money demand equation with inflation acting as a proxy for the (missing) market interest rate. Real output in the long run is shaped by oil exports through their impact on capital accumulation, and the foreign output as the main channel of technological transfer. The results also show a significant negative long run association between in‡ation and real GDP, which is suggestive of economic inefficiencies. Once the effects of oil exports are taken into account, the estimates support output growth convergence between Iran and the rest of the world. We also find that the Iranian economy adjusts quite quickly to the shocks in foreign output and oil exports, which could be partly due to the relatively underdeveloped nature of Iran’s financial markets.

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