2.4 The Human Impact Flashcards
What are greenhouse gases?
Gases that contribute to the greenhouse effect by absorbing infrared radiation. It is a gas with a high capacity for absorbing long wave radiation.
CO2, Nitrogen, methane and water vapour are greenhouse gases.
What is the greenhouse effect?
Where greenhouse gases act as a blanket, preventing infrared radiation from escaping the atmosphere. It is a natural effect.
What is global warming?
The process whereby the world temperatures are rising. Generally attributed to the greenhouse effect.
What is climate change?
The long term, natural changes to the earth’s climate including rainfall, temperature, and wind. It can mean the climate cools or warms.
What is the enhanced greenhouse effect?
This refers to the addition of greenhouse gases to the atmosphere by human activity. It is thought to lead to global warming.
What does radiative forcing mean?
The warming effect of a gas.
What are biological indicators of warming?
1) The bee-eater, a tropical bird, is now found in the UK each spring
2) Malaria is increasing in southern europe
3) blanching of corals has occurred due to increased acidity of oceans
What is a carbon footprint?
A measure of the amount of carbon dioxide that results from a specific human activity or activities.
What is El Nino?
It is a reversal of the southern equatorial ocean current that occurs in the Pacific Ocean just south of the Equator; it flows from west to east, warming the waters along the coast of Peru.
Low pressure and hot water near South America lead to rising air and heavy rainfalls.
Descending cool air at the high pressure near Australia leads to dry conditions.
An El Nino event occurs every 2-7 years, lasting for 12-18 months.
It has a global impact on weather patterns - droughts in Asia, tropical storms in Japan.
What is La Nina?
A strong movement of warm water from east to west that sometimes flows just south of the Equator in the Pacific Ocean, leading to very heavy rains in north east Australia and cooler than average conditions in Peru.
It is an exaggeration of the normal conditions. Strong trade winds move warm water West, and cold water replaces it in the east having been pulled up from the deeper ocean (upwelling). Warm rising air in the West leads to unsettled weather.
What is an urban heat island?
When urban areas are warmer than their rural surroundings.
What is anthropogenic heat?
Heat released by human activity
