Some Background Information About Climate

On climate

DEPARTMENT OF EDUCATION

What’s the difference between weather and climate?

On climate

DEPARTMENT OF EDUCATION

Weather: state of the atmosphere in a given place over a short period of time (minutes to months)

Climate: how the atmosphere behaves over relatively long periods of time (usually measured over 30 years or so)

On climate

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What’s the greenhouse effect?

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Greenhouse effect: when certain gases in the air trap radiation coming from Earth’s surface

On climate

DEPARTMENT OF EDUCATION

On climate

DEPARTMENT OF EDUCATION

What’s the difference between climate change and global warming ?

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Climate change: deviation from climate normals (mostly, changes in temperature and precipitation averages in a given place for a period of time)

Global warming: rise in the average temperature of the Earth

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DEPARTMENT OF EDUCATION

References:

Environmental Protection Agency (EPA)

National Oceanic and Atmospheric Administration (NOAA)

National Aeronautics and Space Administration (NASA)

Global climate change is…

Global climate change refers to the significant changes in temperature, precipitation, wind and other measures of climate lasting through an extended period of time, which may be caused by human activities and natural processes (EPA, 2010).

Global climate change may involve…

• Increase in average global temperature

• Intensified weather disturbance• Threats from vector-borne diseases• Problems on food security• Ocean acidification• Sea-level rise• Coral bleaching

• The Intergovernmental Panel on Climate Change (IPCC) (2002) projects that the globally averaged surface temperature will increase by 1.4 to 5.8 °C from 1990 to 2100, with land areas warming more rapidly than the global average.

• Francis and Hengeveld (1998) posit that greenhouse warming causes increase in extreme weather conditions, such as tropical storms and hurricanes, as these result from changes in the distribution of heat and flow of energy.

• Food security is also at risk with global climate change by potentially affecting plant growth, plant susceptibility to diseases and crop yield. Elevated carbon dioxide levels result in changed plant structure and that elevated temperature induces stress resulting in wilting, leaf burn, leaf folding, and changes in metabolism.

Coral Bleaching

• reduced/no skeletal growth and reproductive activity, and a lowered ability to shed sediments and disease resistance (Glynn, 1996).

• Ocean acidification reduces ocean carbonate ion concentrations and the ability of corals to build skeletons (Carpenter et al., 2008).

Sea Level Rise

• Thermal expansion• Melting of glaciers and the Antarctic and

Greenland ice sheets• average of 65 cm (approximately 6 cm per decade)

(IUCC).• from 2 to 12 ft (0.6-3.6 meters) by the year 2100

(IUCC).

Cryosphere

• composed of freshwater glaciers, sea ice, and continental ice sheets and caps,

• is one of the four major “spheres” that regulate our climate.

• Glaciers are masses of land ice which flow downhill under gravity and form by the accumulation of snow at high altitudes (IPCC).

• Sea ice is any major ice mass found at sea that has originated from the freezing of sea water (IPCC) and is therefore already part of the ocean’s total volume.

• Ice sheets are large masses of land ice that cover most of the underlying bedrock of the continents which they are found on; ice caps are defined similarly, but are considerably smaller (IPCC). There are only three large continental ice sheets found in the modern world: two in Antarctica and one in Greenland (IPCC).