Challenges for the Planet Flashcards
What is weather?
The state of the atmosphere at any given time and place
What is climate?
The average weather conditions over a long period of time (at least 30 years)
How has the worlds climate changed since the last ice age?
temp. rise
Over past 10,000 years the temperature has risen by 6°C. The projected temperature is still rising.
There were many fluctuations between 4 and 6°C between the years of 6800 BC and 2000 AD.
What are the 2 types of factors that have affected the worlds climate change since the last ice age?
External factors
Internal Factors
What are the External factors that have affected the worlds climate change since the last ice age?
Solar output
Orbital geometry
What are the Internal factors that have affected the worlds climate change since the last ice age?
Volcanic activity
Surface reflection
Change in atmospheric gas
Tectonic activity
Explain solar output and its effects
Energy that comes from the sun
Studies (1980’s) show this has decreased by 0.1 percent
Not much but over large scale of time could affect global climate
Reduced sunspot activity may have caused the Little Ice Age (1645 and 1715)
Explain Orbital geometry and its effects
- Shape of Earth’s orbit
Colder periods when orbit is circular
Warmer periods when orbit is more elliptical - Tilt of Earth’s axis
Greater angle - hotter summers and colder winters
When angle is greater earth experiences warmer periods
Explain Volcanic activity and its effects
Release sulfur dioxide and ash
Act as cloak and reduce amount of solar radiation/energy reaching Earths surface
1816 “year without summer” after Mount Tambora erupted
Explain Surface reflection and its effects
During cool period when there is ice and snow the temperature will drop because the ice and snow will reflect sunlight back to space. When the planet warms up this diminishes and the Earth gets warmer
Explain Change in atmospheric gas and its effects
There is a clear relationship between CO2 and temperature variation
Responsible for greenhouse effect - keeps heat in
Explain Tectonic activity and its effects
Continent movement - caused by tectonic plates - affects ocean circulation and causes wind and ocean currents to change
This process is too slow to have an impact over the span of 10,000 years
What are the causes of current climate change?
Explain
Fossil fuels - (coal, oil, natural gas) when burnt gases are released. CO2 causes greenhouse effect - global warming
Methane - greenhouse gas(20 percent of g.h.g in atmosphere) Comes from: Wetlands+mashes+swamps Growing of rice Landfills(rotting vegetable matter) Burning vegetation Bowels of animals
What are the negative effects of cimate change
Changing pattern of crop yields
Rising sea levels
Retreating glaciers
Changing pattern of crop yields
Countries near equator suffer from decreasing yields
Tanzania/Mozambique - long periods of drought with shorter growing seasons
Rising sea levels
Studies show a rise of 3.3mm a year - 88cm by end of century
Threaten areas of low lying land, many island are being evacuated before they are covered/engulfed by sea water