Global Warming – Causes & Effects Chapter 2 Section 2 p

First…some basics on climate  WEATHER = short-term, day to day, expression of atmospheric processes(rainy, cloudy, sunny, snowy, etc.)  CLIMATE = long-term (usually 30 year) picture of daily weather data; allows an overall picture to be formed for a region.

Other “climate” basic terms:  There are 2 main factors that effect climate: elevation (elevation above sea level) AND latitude (distance from the equator. Additional factors include proximity to water, global pressure and wind systems.  GREENHOUSE EFFECT – refers to how the incoming solar energy (“insolation”) is trapped in the earth’s lower atmosphere creating a warm envelope that makes it possible to live here.

So what is GLOBAL WARMING?  The natural GREENHOUSE EFFECT seems to have been accelerated & now we are seeing a general overall rise in the earth’s temperatures. Scientists attribute this rise to human caused or ANTHROPOGENIC activity. This is where our actions seem to be changing the earth’s atmosphere in arguably negative ways.  Severe Weather doc Severe Weather doc

Causes (Reasons why it happens)  CO2 – Carbon Dioxide  Accounts for greater than half of the human generated greenhouse gases (GHG’s). Major cause is burning fossil fuels like petroleum and coal.

CAUSES…  CFC’s – Make up 25% of human generated GHG’s – due mostly to widespread usage of aerosol sprays & refrigeration (AC). Because these stay in the atmosphere so long (100 yrs) their role in global warming is significant.

CAUSES…  METHANE – 151% increase since 1750 – due mostly from vegetation burning associated with rainforest clearing.

CAUSES…  NITROUS OXIDE – just over 5% of anthropogenic (HUMAN CAUSED) ghg’s. Results mostly from widespread useage of chemical fertilizers used in modern agriculture.

EFFECTS (OUTCOMES)  Average global temperatures will rise, causing all sorts of potential natural disasters (melting polar ice caps threaten sea life & surrounding habitat; more severe hurricanes, etc)

EFFECTS…  This temperature change could cause a shift in major agricultural areas…resulting in…

EFFECTS…  A MAJOR DECREASE IN THE WORLD’S GRAIN PRODUCTION BY THE YEAR 2030.

EFFECTS…  Rising sea levels which will endanger low lying island nations which may actually be flooded out of existence.

KYOTO PROTOCOL  SIGNIFICANCE: it was the 2 nd attempt to develop an intl. treaty on GW (1 st one in Rio failed in 1992)  OUTCOME: produced the Kyoto Protocol. 38 industrialized countries agreed to reduce their GHG emissions to below 1990 levels by If its ratified by countries emitting 55% of GHG’s, it’s the LAW.

POSITION OF THE USA…  POSITION: Supported by Pres. Clinton; Opposed by Pres. Bush  REASONS: There is concern that restrictions on atmospheric emissions could hurt the US economy; also, the Pres. wants to see LDC’s become bound by GHG reductions, & the current treaty does not do that.

EUROPEAN UNION (EU)…  POSITION: Strongly support the Treaty  REASONS: Europe is more energy efficient than the US & can meet reduction quotas more easily. Also, the EU may meet their cutback quotas as a GROUP rather than as individual nations. Finally, EU nations have significantly lowered their dependence on coal.

LESS DEVELOPED COUNTRIES (LDC’s)…  POSITION: Reluctant to support the treaty.  REASONS: Their position is that since they did little if anything to contribute to the problem, they don’t want to sign the treaty. Also they fear that an emission control agreement might constrain their economic development.