Definitions - j

Jatropha Curcas is a bio-fuel crop that is being widely touted as a sustainable and more efficient alternative to first generation feed stocks, such as corn and palm oil.

Firms seeking to commercialise the jatropha-based biofuels, argue that the plant delivers high yields of oil and can be grown in marginal areas with low levels of water, limiting the extent to which cultivation would eat into existing agricultural land and water resources.

Rivers of high-speed air in the atmosphere. Jet streams form along the boundaries of global air masses where there is a significant difference in atmospheric temperature. The jet streams may be several hundred miles across and 1-2 miles deep at an altitude of 8-12 miles. They generally move west to east, and are strongest in the winter with core wind speeds as high as 250 mph. Changes in the jet stream indicate changes in the motion of the atmosphere and weather

Toxicity can be acute, subchronic, or chronic:

• Acute toxicity involves harmful effects in an organism through a single or short-term exposure.
• Subchronic toxicity is the ability of a toxic substance to cause effects for more than one year but less than the lifetime of the exposed organism.
• Chronic toxicity is the ability of a substance or mixture of substances to cause harmful effects over an extended period, usually upon repeated or continuous exposure, sometimes lasting for the entire life of the exposed organism.