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4. What is meant by “convection'? Explain with the help of an example. Why is it that convection ca
take place in solids?
What is meant hy acid rain? How is acid rain caused? What damage is caused by acid rain?
Answers
Answer:
absolute humidity: The mass of water vapour in a given volume of air.
acclimatization: Physiological and/or behavioural adaptation to climate.
acid rain (deposition): Precipitation that has a pH lower than about 5.0, the
value produced when naturally occurring carbon dioxide, sulfate and nitro-
gen oxide dissolve into water droplets in clouds. Increases in acidity may
occur naturally (e.g. following emissions of aerosols during volcanic eruptions)
or as a result of human activities (e.g. emission of sulfur dioxide during fossil
fuel combustion).
acute effect: Short-lived effect (in contrast to chronic effect).
adaptability: See adaptive capacity.
adaptation: Adjustment in natural or human systems to a new or changing
environment. Adaptation to climate change refers to adjustment in response
to actual or expected climatic stimuli or their effects, which moderates harm
or exploits beneficial opportunities. Various types of adaptation can be distin-
guished, including anticipatory and reactive adaptation, public and private
adaptation, and autonomous and planned adaptation.
adaptation assessment: The practice of identifying options to adapt to climate
change and evaluating them in terms of criteria such as availability, benefits,
costs, effectiveness, efficiency, and feasibility.
adaptation costs: Costs of planning, preparing for, facilitating, and implement-
ing adaptation measures, including transition costs.
adaptive capacity: The ability of a system to adjust to climate change
(including climate variability and extreme events) to moderate potential
damages, take advantage of opportunities or cope with the consequences.
aeroallergen: Any of various airborne substances, such as pollen or spores,
which can cause an allergic response.
aerosol: A collection of airborne solid or liquid particles with a typical size of
0.01–10mm which are present in the atmosphere. Aerosols are an important
source of negative radiative forcing and acid rain.
age related macular degeneration (AMD): An acquired degenerative disease
which affects the central retina of patients most commonly over the age of 60.
air mass: Synoptic meteorological characterization of the entire body of air and
its qualities. Air masses can be determined empirically using a combination
of meteorological variables which include temperature, relative humidity,
wind speed, wind direction, and barometric pressure.
albedo (whiteness): The fraction of solar radiation reflected by a surface or
object, often expressed as a percentage. Snow covered surfaces have a high
Glossary1
1 The glossary was prepared by Katrin Kuhn, London School of Hygiene and Tropical Medicine,