SCITECH TOPIC 14
SPECIFIC ISSUES IN STS
(6) GLOBAL CLIMATE CHANGE
Lesson Objectives
At the end of this lesson, the students should be able to:
• identify the causes of climate change
• understand the effects of climate change on the society; and
• illustrate how the community helps in mitigating the hazards caused
by climate change.
OVERVIEW
o Introduction to Climate Change
• Causes of Global Climate Change
o Effects of Climate Change
• Melting Ice and Rising Sea Level
• Changes in Precipitation Patterns
• Effects on Organisms
• Effects on Human Health
• Effects on Agriculture
o Dealing with Global Climate Change
Climate Change
Climate change is referred as statistically significant climate variation persisting for an
extended period of time.
Global Warming
o is the term used to describe a gradual increase in the average temperature of the
Earth’s atmosphere and its oceans, a change that is believed to be permanently
changing the Earth’s climate.
SCITECH TOPIC 14
Climate Change–
Mean Annual Global Temperature 1960-2005
Climate Change Terminology
o Greenhouse Gas
• Gas that absorbs infrared radiation
• Ex: Carbon dioxide, methane, nitrous oxide, chlorofluorocarbons and
tropospheric ozone
o Positive Feedback
• Change in some condition triggers a response that intensifies the changed
condition
o Infrared Radiation
• Radiation that has a wavelength that is longer than that of visible light, but
shorter than that of radio waves
o Greenhouse Effect
• Increase of heat in a system where energy enters (often as light), is
absorbed as heat, and released sometime later
Climate Change
o Evidence for Climate Change
• 11 of the 12 years between 1995 and 2006 were among the twelve warmest
years since the mid-1800s
• Phenological spring in N. hemisphere now comes 6 days earlier
SCITECH TOPIC 14
o Warming is not due to natural causes
• Human produced greenhouse gases are most plausible explanation
Causes
o Greenhouse gas concentrations increasing
o Increased concentration of CO2 (right)
• Burning fossil fuels in cars, industry and
homes
• Deforestation
• Burning of forests
Greenhouse Effect
SCITECH TOPIC 14
Climate Models
o Climate affected by:
• winds, clouds, ocean currents, and
albedo (the proportion of the incident
light or radiation that is reflected by a
surface, typically that of a planet or
