Human activities are changing the atmosphere in dangerous ways by increasing levels of greenhouse gases like carbon dioxide and methane, causing global warming. This is raising average global temperatures and will lead to problems like rising sea levels, more extreme weather, effects on agriculture and human health. While warmer temperatures may slightly increase some crop yields, issues like droughts and disease spread outweigh any benefits. Addressing this problem will require coordinated global action between citizens, corporations, and governments to develop green technologies and reduce emissions.

2. • Human activities are now changing the composition
of the atmosphere in ways that most authorities
conclude will be damaging or, in the long
run, disastrous.
• Global warming
–Changes in atmospheric composition
–Average temperature of the Earth’s surface is
increasing

5. • CO2 strongly absorbs electromagnetic radiant
energy at some of the wavelengths that are critical
for the global heat budget.
• Greenhouse gases
– CO2
– Methane
– Nitrous oxide

7. • Many insects and amphibians breed earlier in the
year
• Many plants flower earlier
• Concerns:
– The rate of warming today is rapid
– Natural areas no longer cover the whole landscape
– As temperature increases

8. Rising sea levels
Other climatic effects
Effects on agriculture
Effects on human health
Solving the problem

9. • Two effects of global warming
– The melting of polar ice
and glaciers, adding water
to the ocean
– The increase of average
ocean temperature, causing
an increase in volume because
water expands as it warms

10. • Frequency or severity of extreme meteorological
events
– Heat waves
– Droughts
– Severe storms
– Hurricanes
– El Niño
– Rainfall patterns

11. • Positive side
– Warmer temperatures and increase atmospheric CO2
tend to increase growth of some crops and thus may
increase agricultural yields.
• Negative side
– Droughts
– Changes in rainfall patterns
– Temperature
– Pest distributions

12. • Loss of safe drinking water
– Epidemics of cholera
• Human diseases
– Diseases transmitted by mosquitoes
• Temperatures above 16⁰C
– Malaria
• Temperatures above 10⁰C
– Yellow fever
– Dengue fever
• Higher temperature
– Malaria pathogens mature
more rapidly

13. • “green” technologies
• Concerted efforts from:
– Citizens
– Corporations
– Governments