Global WarmingGlobal Warming

Environmental ScienceEnvironmental Science

January 4, 2011January 4, 2011

What’s been happening?What’s been happening?

• Since the Industrial revolution human activity has significantly changed.– Think about it… how did the early settlers

compare to our lifestyle?– What is different?

• CO2 concentrations have had a dramatic increase in the last 50 years.. It is now at the highest it has ever been.

• Methane has also been at its highest concentration ever.

• Nitrous Oxide has had a significant spike and is at the highest in recorded history.

How do we know this??How do we know this??

• We weren’t around in 20,000 B.C so how did we get this info?

Ice cores can tell us a lot about ancient climates, including local temperature, CO2 concentration and, based on dust trapped in the ice, global and local wind patterns.

Where do these gases come from?Where do these gases come from?

• Carbon Dioxide (CO2) – Source: Fossil fuel burning, deforestation Anthropogenic increase: 30% Average atmospheric residence time: 500 years

Methane (CH4) – Source: Rice cultivation, cattle & sheep ranching, decay from

landfills, mining Anthropogenic increase: 145% Average atmospheric residence time: 7-10 years

Nitrous oxide (N2O) – Source: Industry and agriculture (fertilizers) Anthropogenic increase: 15% Average atmospheric residence time: 140-190 years

What does this mean?What does this mean?

• Why should we care if there is global warming or not?– A group of Scientists called the

Intergovernmental Panel on Climate Change have been trying determine what is happening and how it will effect us.

This is what they think!This is what they think!• Obviously the overall temperature is suspected

to rise by 2- 11.5 degrees C– Not evenly though… land will be warmer then oceans.

– Higher altitude will warm more then lower altitude due

to the ice absorbing heat.– Most of North America; all of Africa, Europe, northern

and central Asia; and most of Central and South America are likely to warm more than the global average

– The warming will differ by season, with winters warming more than summers in most areas.

This is what they think!This is what they think!• An increase in global average annual precipitation during the

21st century, although changes in precipitation will vary from region to region.

• An increase in the intensity of precipitation events, particularly in tropical and high-latitude regions that experience overall increases in precipitation.

• Annual average precipitation increases over most of northern Europe, the Arctic, Canada, the northeastern United States, tropical and eastern Africa, the northern Pacific, and Antarctica, as well as northern Asia and the Tibetan Plateau in winter.

• Annual average precipitation decreases in most of the Mediterranean, northern Africa, northern Sahara, Central America, the American Southwest, the southern Andes, as well as southwestern Australia during winter.

• Reduced rainfall over continental interiors during summer due to increases in evaporation.

This is what they think!This is what they think!

• Higher temperatures are expected to raise sea level by:– expanding ocean water, – melting mountain glaciers and small ice caps, – causing portions of the coastal section of the

Greenland and Antarctic ice sheets to melt or slide into the ocean.

What does sea level rise mean?What does sea level rise mean?

• http://geology.com/sea-level-rise/washington.shtml

Is this Human Caused?Is this Human Caused?

• Climate variability is natural. • Even in a stable climate regime, there will

always be some variation (wet/dry years, warm/cold years) A year with completely “average” or “normal” climate conditions is rare

• The challenge for scientists is to determine whether any increase/decrease in precipitation, temperature, frequency of storms, sea level, etc. is due to climate variability or climate change.

• It is your decision…

Things we can doThings we can do

• http://www.youtube.com/watch?v=42HLOxVZAYo

Government plansGovernment plans

• In 1992, the Kyoto Protocol called for a 5% reduction in carbon emissions by 2012. The US did not sign this treaty.

• Copenhagen

• Montreal Protocol

Global Warming factsGlobal Warming facts

• The ice cap on Mount Kilimanjaro may be gone in 20 years. About 1/3 of Kilimanjaro’s ice field has disappeared in the last 12 years and 82% of it has vanished since it was first mapped in 1912.

• Sea ice in the Arctic Ocean is thinning.

• Many animals depend on these areas for food and shelter.

Global Warming FactsGlobal Warming Facts

Global Warming FactsGlobal Warming Facts

• Mass extinction of animals

Use the following words to create a Use the following words to create a crossword puzzlecrossword puzzle

• Global Warming• Industrial Revolution• Climate• Weather• Solar Radiation• Atmosphere• Greenhouse Gas• Glacier• Ice cores

• Plus 10 more words of your choice from yesterdays PowerPoint concerning global warming