How do we know that climate change is definitely happening?
Let's explore some of the lines of evidence.
On your own paper, answer the questions in each section. Click on the links to find the answers.
Let's explore some of the lines of evidence.
On your own paper, answer the questions in each section. Click on the links to find the answers.
Arctic Sea Ice Has RetreatedWe can use satellite images to see the changes to the Earth.
Question 1: Northern polar ice caps might vanish within how many years?
Storms--More Severe
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Ice Sheets Are MeltingIce Sheet Loss at Both Poles Increasing, Study Finds
11.29.12 PASADENA, Calif. - An international team of experts supported by NASA and the European Space Agency (ESA) has combined data from multiple satellites and aircraft to produce the most comprehensive and accurate assessment to date of ice sheet losses in Greenland and Antarctica and their contributions to sea level rise. In a landmark study published Thursday in the journal Science, 47 researchers from 26 laboratories report the combined rate of melting for the ice sheets covering Greenland and Antarctica has increased during the last 20 years. Together, these ice sheets are losing more than three times as much ice each year (equivalent to sea level rise of 0.04 inches or 0.95 millimeters) as they were in the 1990s (equivalent to 0.01 inches or 0.27 millimeters). About two-thirds of the loss is coming from Greenland, with the rest from Antarctica. Question 2: Much of Greenland's annual ice mass loss occurs when icebergs break free from glaciers. What is the term for this process? sea levels are rising quicklyBoulder, Colorado, USA
Sea levels are rising faster than expected from global warming, and University of Colorado geologist Bill Hay has a good idea why. The last official IPCC report in 2007 projected a global sea level rise between 0.2 and 0.5 meters by the year 2100. But current sea-level rise measurements meet or exceed the high end of that range and suggest a rise of one meter or more by the end of the century. "What's missing from the models used to forecast sea-level rise are critical feedbacks that speed everything up," says Hay. He will be presenting some of these feedbacks in a talk on Sunday, 4 Nov., at the meeting of The Geological Society of America in Charlotte, North Carolina, USA. Question 4: List the feedbacks that speed up sea-level rise. Choose one and explain how it works. Oceans Are Becoming More AcidicDisappearing Coral Reefs
Delicate corals may face an even greater risk than shellfish because they require very high levels of carbonate to build their skeletons. Acidity slows reef-building, which could lower the resiliency of corals and lead to their erosion and eventual extinction. The “tipping point” for coral reefs could happen as soon as 2050. Question 6: What impact would the loss of coral reefs have on coastal communities? |