Groundwater is a primary source of fresh water in many parts of the world. Some regions are becoming overly dependent on it, consuming groundwater faster than it is naturally replenished and causing water tables to decline unremittingly. Indirect evidence suggests that this is the case in northwest India, but there has been no regional assessment of the rate of groundwater depletion.
The increasing wealth of nations is accompanied by a fall in fertility such that in many developed and developing nations fertility rates have dropped below replacement value (less than 2.1 children per woman). Rapid population ageing, and in some cases the prospect of significant population decline, present difficult social and political problems.
The low 13C/12C ratio in some Neoproterozoic carbonates is considered to be evidence of carbon cycle perturbations unique to the Precambrian. Here, all published oxygen and carbon isotope data for Neoproterozoic marine carbonates are compiled.
The population of some wealthy countries is shrinking because of a declining birth rate. It comes as a surprise, and one with policy implications, that after a certain point of development that trend can reverse.
India's prime minister Manmohan Singh has approved a US$19 billion plan to make the country a global leader in solar energy over the next three decades. The ambitious project would see a massive expansion in installed solar capacity, and aims to reduce the price of electricity generated from solar energy to match that from fossil fuels by 2030.
The United States and China adjourned a new round of bilateral talks in Washington DC last week with the vague outline of a climate partnership. But the
The feedback between the terrestrial carbon cycle and climate is one of the largest uncertainties in current projections of future climate, with the long-term sensitivity of carbon in peatlands remaining unclear.
Across the United States, researchers are firing up experiments to determine how rising temperatures could reshape the nation's forests. The studies encompass the pines and maples of eastern forests in Massachusetts and North Carolina, the spruce and fir of northern Minnesota, and the alpine tundra ecosystem above the treeline in the Rocky Mountains in Colorado.
