1. Threats to Biodiversity Climate Change
Chapter 43
Threats to Biodiversity
Climate Change

2. You Must Know
How human actions are changing the Earth.

3. Greenhouse Gases and Climate Change
One pressing problem caused by human activities is the rising concentration of atmospheric CO2 due to the burning of fossil fuels and deforestation

4. CO2 concentration (ppm)
Figure 43.26
14.9
390
14.8
380
14.7
14.6
370
Temperature
14.5
360
14.4
CO2 concentration (ppm)
350
14.3
Average global temperature (C)
14.2
14.2
340
14.1
CO2
330
14.0
Figure Increase in atmospheric carbon dioxide concentration at Mauna Loa, Hawaii, and average global temperatures
Climatologists can make inferences about prehistoric climates. CO2 levels are inferred from bubbles trapped in glacial ice. Chemical isotope analysis is used to infer past temperature.
13.9
320
13.8
310
13.7
300
13.6
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
Year 4

5. https://climate.nasa.gov/vital-signs/carbon-dioxide/

6. CO2, water vapor, and other greenhouse gases reflect infrared radiation back toward Earth; this is the greenhouse effect. This effect is important for keeping Earth’s surface at a habitable temperature. Increasing concentration of atmospheric CO2 is linked to increasing global temperature.

7. http://time.com/5559516/netflix-our-planet-glacier-david- attenborough/

8. Organisms are adapted to the environment in which their ancestors evolved.

9. Figure 43.27
Many organisms, especially plants, may not be able to disperse rapidly enough to survive rapid climate change. Researchers can track changes in tree distributions since the last period of glaciation to help infer future changes due to climatic warming
(a) Current range
(b) 4.5C warming over next century
(c) 6.5C warming over next century
Current range and predicted range for the American beech under two climate-change scenarios 9

10. Climate Change Solutions
Global warming can be slowed by reducing energy needs and converting to renewable sources of energy.
Reduced deforestation would also decrease greenhouse gas emissions.