12.19: Impact of Continued Global Warming

“The land is part of me...”

"The future kind of scares me, just thinking about how we're going to survive." says 18-year old Harlie Potter, an Inuit living in the autonomous area of Nunatsiavut in Newfoundland, Canada. Native people in the Arctic see changes much more than people in lower latitudes. Warming is occurring more rapidly in the polar regions.

How Will Climate Change in the Future?

Earth’s temperature will keep rising unless greenhouse gas emissions are curbed. The temperature in 2100 may be as much as 5° C (9° F) higher than it was in 2000. Is 5° C (9° F) a lot? It's more than the increase in temperature from the the times of maximum ice during the Pleistocene to now. Since the end of the Pleistocene, the temperature has only risen about 4° C. That's just 4° C from abundant ice to the moderate climate we have today. How might a 5° C increase in temperature affect Earth in the future?

Warming will affect the entire globe by the end of this century. The map in Figure below shows how much temperatures will change in different regions based on the Coupled Climate 2.1 model. In what place is the temperature increase the greatest? Where in the United States is the temperature increase the highest?

The Arctic will experience the greatest temperature changes.

What Will Happen?

As temperature rises, more sea ice will melt. The figure below shows how much less sea ice there may be in 2050 if temperatures keep going up (Figure below). This would cause sea level to rise even higher. Some coastal cities could be underwater. Millions of people would have to move inland. How might other living things be affected?

In the 2050s, there may be only half as much sea ice as there was in the 1950s.

Weather will become more extreme. Heat waves and droughts will become more frequent and more intense. The Midwestern United States will become hot and dry. This will make growing food more difficult. Cropland worldwide will be affected. Hurricanes may become more severe.

Plants and animals will move or die out. Some will thrive in a warmer world, but most will not. The biosphere may become quite different.

These are only a few of the impacts warmer temperatures will have. The vast majority of scientists agree that this is what is happening.

Summary

• Global temperatures will increase. Some locations like the Arctic and Amazon will experience a greater increase.
• Sea level will rise and some coastal cities may be submerged.
• Weather will become more extreme. Crops and some plants and animals may not be able to survive the warmer temperatures.

Review

1. Pretend that the temperature today is 5° C (9° F) higher than yesterday. Now consider an increase of 5° C (9° F) in average global temperature. How are these two scenarios different?
2. Why is a rise in sea level significant?
3. What will plants and animals do as temperature rises?

Explore More

Use the resource below to answer the questions that follow.

1. Climate has always been changing. Why is it something to worry about now?
2. Describe the changes that could be seen if the Earth warms by one degree.
3. Describe the effects of two degrees of warming.
4. What changes will occur with three degrees of warming?
5. Describe the consequences of four degrees of warming.