Anthropogenic metal cycles in China

The flows and stocks of seven important industrial metals were characterized for mainland China for several years in the dynamically changing decade of 1994–2004. One-year snapshot cycles are provided for chromium, nickel, and silver. For copper, zinc, lead, and iron, multiple-year cycles have been completed; they demonstrate that the flows of these metals into use in China doubled between 2000 and 2004. Although the Chinese per capita flows from production to disposal are mostly shown to be below the global average rate, they are increasing or are expected to increase dramatically. The metal resource efficiency is evaluated for several indicators of material flow analysis; these metrics for China are also below the global average values. The research quantitatively illustrates that China’s metal cycles may pose significant resource and environmental challenges in terms of their magnitudes and potential for growth.     

Carbon dioxide and climate: Comparison of one- and three-dimensional models

Calculations indicate that there may be a potential climatic problem due to the release of CO₂ from burning fossil fuels. However there is insufficient scientific evidence to predict the impact because the available models are not well enough understood and do not take into account many feedback mechanisms. Therefore, we have calculated atmospheric temperature changes versus latitude with the simpler Manabe-Wetherald radiative-convective model and compared it to the results of their general circulation model. In addition, we have determined the changes in several physical quantities, such as cloud abundance and surface albedo, required to compensate the temperature rise related to increased CO₂ concentrations.