A History of Global Climate Change

Many scientists expect global temperatures to _______ by 2100. a. rise 0.4-1.4ºC b. rise 1.4-5.8ºC c. fall 0.4-1.4ºC d. fall 1.4-5.8ºC

B.

Which of the following is predicted to be an impact of global warming? a. extreme weather b. ocean acidification c. species extinction d. all of the above

D.

Explain how glaciers can change the landscape and physical characteristics of continents.

The advancing front of a glacier acts like a bulldozer, scraping across the landscape and carving out new features. This can carve out new courses for rivers and lakes and flatten out landscapes.

Why did scientists think the world was experiencing global cooling between the 1940's and 1970's. a. Pollution was blocking sunlight. b. Pollution was trapping heat in the atmosphere. c. Winters were the longest and coldest since the last ice age. d. Biodiversity was declining.

A.

Without the greenhouse effect, Earth would be _______. a. too cold to support our current ecosystem b. too warm to support our current ecosystem c. too wet to support our current ecosystem d. barren of all life

A.

Which of the following continents was covered by glaciers during the Pleistocene ice age? a. Europe b. South America c. Australia d. Africa

A.

Explain why entering an interglacial period resulted in an increase in biodiversity on Earth.

During an ice age the conditions on Earth favor glaciers and cold deserts over more hospitable environments. Therefore, when the ice age ended and glaciers retreated the more hospitable grasslands and forests that developed hosted greater biodiversity.

Explain why scientists are concerned about human activities that cause global warming if global warming is caused by the greenhouse effect and the greenhouse effect is a natural part of Earth's climate.

Even if global warming is a natural part of Earth's climate, human activities are accelerating it. Global temperatures are expected to rise much faster than they would have naturally, which may result in severe environmental and climate changes across the globe. These predicted impacts of global warming could have severe, negative impacts to humans.

Explain why some groups doubt the occurrence of global warming and global climate change.

Some groups point out that water is a more significant contributor to warming in the atmosphere. Therefore, they argue that carbon dioxide is not a significant greenhouse gas so any observed warming is not the result of human activity. To many of these groups any discussion of global warming or climate change is a form of media alarmism.

Explain why the greenhouse effect is not entirely a man-made phenomenon.

While many human activities produce greenhouse gases, the greenhouse effect is actually a natural process. Many atmospheric gases help trap heat in Earth's atmosphere, including natural gases like carbon dioxide. So while human activities exacerbate the natural greenhouse effect, it is not solely due to them.