Global Warming – Causes & Effects

Chapter 2 Section 2

p. 60-63

Causes (Reasons why it happens)

CO2 – Carbon DioxideAccounts 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 2nd attempt to develop an intl. treaty on GW (1st 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 2012. 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.