Emissions of a broad range of greenhouse gases of varying lifetimes contribute to global climate change. Carbon dioxide displays exceptional persistence that renders its warming nearly irreversible for more than 1,000 y.

Phytoplankton biomass and productivity have been continuously monitored from ocean color satellites for over a decade. Yet, the most
widely used empirical approach for estimating chlorophyll a (Chl) from satellites can be in error by a factor of 5 or more.

The combustion of fossil fuels has enriched levels of CO2 in the world

The waters of the Colorado River serve 27 million people in seven states and two countries but are overallocated by more than 10% of the river

Great effort continues to focus on ecosystem restoration and reduction of nutrient inputs thought to be responsible, in part, for declines in estuary habitats worldwide. The ability of environmental policy to address restoration is limited, in part, by uncertainty in the relationships between costly restoration and benefits.

Aerosols could be injected into the upper atmosphere to engineer the climate by scattering incident sunlight so as to produce a cooling tendency that may mitigate the risks posed by the accumulation of greenhouse gases. Analysis of climate engineering has focused on sulfate aerosols.

Global demand for agricultural products such as food, feed, and fuel is now a major driver of cropland and pasture expansion across much of the developing world. Whether these new agricultural lands replace forests, degraded forests, or grasslands greatly influences the environmental consequences of expansion.

Efforts to mitigate climate change through the Reduced Emissions from Deforestation and Degradation (REDD) depend on mapping and monitoring of tropical forest carbon stocks and emissions over large geographic areas.

Intake of toxic cadmium (Cd) from rice caused Itai-itai disease in the past and it is still a threat for human health. Therefore, control of the accumulation of Cd from soil is an important food-safety issue, but the molecular mechanism for the control is unknown.

Antibiotics can cause long-lasting changes in the bacteria living in the human gut. As changes in gut flora could increase the risk of some chronic diseases, such as inflammatory bowel syndrome, each course of antibiotics may represent a trade-off between short-term benefit and long-term risk.