Eviro. Unit 8 Lesson 6: Evidence for Climate Change

How does extreme weather show evidence of a warmer earth?

-Record-high temperatures have increased while record-low temperatures have decreased. -The number of extremely intense occurrences of severe storms has increased. -The number of intense rainfall events has increased.

Select three things that cause scientists to think climate change is caused by humans.

-computer modeling -the way different layers of the atmosphere are warming -type of carbon dioxide in the atmosphere

Select the natural causes for climate change.

-slight changes in the earth's orbit -changes in solar output -volcanic activity

How much has carbon dioxide increased since measurements were first recorded on a daily basis?

400 ppm in 2013 - 315 ppm in 1950s = 85 ppm

​​​​How do warmer temperatures show evidence of a warmer earth?

In the last 100 years, the average global temperature has increased by 1.53 °F, or 0.85 °C.

How does rising ocean levels show evidence of a warmer earth?

In the last century, the oceans have risen about 17 centimeters, or 6.7 inches.

Does correlation mean causation?

No; If a correlation is found, that simply means that there might be a relationship between two variables, not that one variable causes the other variable.

​​​​How does acidification show evidence of a warmer earth?

Since the industrial revolution, the surface of the ocean has increased its acidity by 30%.

​​​​How does an increase in carbon dioxide show evidence of a warmer earth?

The NOAA estimates that carbon dioxide levels have increased from 285 ppm to over 400 ppm.

Why does the way the different layers of the atmosphere are warming prove anthropogenic global warming?

The boundary between the layers has shifted upward likely from the accumulation of greenhouse gases in the troposphere. The stratosphere has been shown to have cooled in recent years. If the sun was the main climate factor, then both layers would have seen increases in temperature.

Why does modeling show humans are responsible for the current global warming trend?

The models that only included natural climate factors such as the intensity of the sun did not accurately portray the observed warming in the last 50 years.

How does a warmer ocean show evidence of a warmer earth?

The top 700 meters of ocean have risen 0.302 °F, or 0.168 °C, since 1970.

​​​​​​​​​​​​​​How does melting ice show evidence of a warmer earth?

There has been an overall reduction in ice-sheet mass over the last three decades. Up to 70% of glaciers around the globe are losing mass.

Scientists believe that much of the warming today has occurred in the _____.

ocean

The abbreviation ppm stands for _____.

parts per million