This paper, based on the rating mechanism, markets and prices of global oil, classifies the evolution of global oil prices into five stages. According to the global oil market prices in every stages, the supply-demand relation is a basic factor to determine the oil price. The cost plays a key role in oil price. However, the US dollar has a big influence over the global oil price. The current oil price and market is manipulated. Moreover, some dubious factors, such as wars, natural disasters, accidents and other sudden outbursts, can also lead to a short fluctuation in oil prices. All these factors mutually exert an influence and control over the global oil prices.

This paper, based on the statistical data of global carbon dioxide emission, estimates the total amount, accumulative amount, per capita amount of carbon emission, and predicts the future carbon emission. Carbon emission is an aftermath of global industrialization. Human being are responsible for reducing carbon emission.
The plan for climate changes shall abide by a principle of "common but with difference in responsibility". The developed countries have a big responsibility in carbon emission since the industrial revolution. The developing countries are responsible for reducing carbon emission though they were late for industrialization. Besides increasing energy efficiency, other renewable energies, lowcarbon technologies, a global specific policy shall be established with a clear and measurable goal to stabilize global atmospheric carbon emissions.

The middle- to long-term prognostication of global energy demands is a key point to study the international energy strategy, so the results are directly related to energy planning and policies. This paper, based on comparison between IEA’s and EIA’s prognostication, presents a big warp between the prognostication and the actual consumption. A further study indicates that there exist unreasonable basic units and deficient methods. This paper, aiming at the problems, presents a new prognostication model system of energy demands which uses the basic prognostication unit that is based on economic-social development in countries, and applies the per capital energy demand and end-use energy demand together.