What reason is there to think that people's opinions about global warming are affected by their political views?

More Republicans live in southern states which are more affected by heat than northern states.
82% of Democrats believe that global warming is a great threat while only 16% of Republicans do.

Why does the fact that scientists in the 1970s used to predict global cooling create doubt  that there their predictions of an upcoming global warming catastrophe are wrong?

Because it didn't keep getting colder.
Because if the scientists were wrong then they could be wrong now.

In the 1970s there were winter storms that were the worst in a century.  There was rising carbon dioxide throughout the century.  Climate alarmists tell us that carbon dioxide is heating the planet.  Would we expect these storms if they were right?

Yes
No

What reasons are there to believe that there might be another ice age coming?

18,000 years ago an ice sheet covered a large part of North America and Manhattan was buried under a mile of ice.
For 30 years before the documentary on the previous page temperatures have been dropping in the North.
Dr. Gifford says in the documentary that the glaciers on Baffin Island are bigger than they were for the last 3,000 years.
At least 8 times in the last million years ice has advanced and retreated with clockwork regularity.

What might be the reason that searching on google turns up links that say that in the 1970s scientists didn't worry about global cooling?

Because people who believe that global warming is an emergency don't want others to question it.
Because most scientists at the time worried about global warming not global cooling.
Because Google employees think that global warming is an emergency and so favor searches that say that scientists didn't worry about global cooling.
Because scientists don't want to admit they were wrong.

20,000 years from now is North America likely to be extremely hot or extremely cold?

hot
cold