Climate

The Final Chapter

What is climate?

• Weather over time

• Decades to centuries

• Measured by precipitation and temperature

Basic Climate facts

Earth's climate has always changed; it is the rate of change that is of current concern to scientists.

• Carbon is critical to the biosphere and must continue cycling to support life on Earth.

• The carbon cycle includes sources, sinks, and release agents.

• Carbon dioxide is an important greenhouse gas.

• Living organisms in an ecosystem can have profound effects upon the local atmosphere.

• Changes in vegetation can have profound effects upon wind speed.

• Understanding the major greenhouse gases is necessary to identify the current trends

• Human activity has been linked with increased greenhouse gases in the atmosphere.

Climate vs. Weather patterns

• Climate is very long term

• Over this time the weather pattern remains the same

• Average of weather patterns

• Broad cycles taken into account

• Weather pattern is a one year trend

• The trend can vary

• Averaged and measured over one to two years

Measuring Climate

• Climate is measured by temperature and climate

• It is then represented in a graph called a climatogram

World Climate Zones

Climate and Biomes

• Climate creates biomes

New England Climate

• Four distinct seasons

• Generally mild overall for temperature

• Moderate rainfall

• Distinctive storm patterns I.e. nor’easter

• Geography and ocean proximity determines climate

What Regulates the Earth’s Climate?

• Eccentricity which is the shape of the Earth’s orbit

• Obliquity which is the tilt of the Earth’s axis compared to the Sun

• Precession which is the rotation of the axis

Other Factors

• The movement of continents• Ocean currents• Glacial cycles

What does this mean over time?

• There have been natural cycles over time.

• We are in a warming trend

• We are adding artificial factors into the atmosphere

The Earth Machine

• Carbon Dioxide is the key factor

• Currently less than .1% of atmospheric gases

• The more the gas, the hotter the planet

• Carbon Dioxide cycles through the atmosphere

• Current carbon dioxide effects are from 100 years ago

Greenhouse Effect

• Increase in Carbon Dioxide traps heat

• Trapped heat creates a rise in temperature

• Result: change in biological and climatological patterns

Past Climates

• There has been climate variation over time

• Much warmer in the past

Ice Age

• Covered 1/3 of the Earth’s surface

• Ice as thick as 2 miles in N.A.

• There have periodic ice ages over Earth’s history

Changing Ocean Currents

• Shutting down the Gulf Stream caused past ice age climate

• Freshwater from melting ice

Evidence

• Rapid melting of polar ice

• Change in mating and migration cycles

• Increase in storm intensity

• No slowdown in greenhouse emissions

What happens if the trend continues?

• Sea Level will rise about twenty feet in less than a century

• Temperature will rise about 12 F on average in that same time period