Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Support PBS Shop PBS Search PBS
Home
Home
Resources for Students
Arts

Science
Math and Economics

World

U.S. History

Health / Fitness

Media
Resources for Teachers & Educators

Click here for more current events lesson plans matched to national standards.

How to use this story in a classroom...

Online NewsHour:
Mayors across the country have united to pledge support for the Kyoto Protocol. 08.15.05

President Bush meets with world leaders; global warming is one of the topics discussed. 07.05.05

Experts discuss possible solutions to international climate change. 07.05.05

A reporter investigates how global warming affects people living in the Arctic. 05.11.05

A discussion on the Kyoto Treaty, and the U.S. decision not to participate. 02.16.05

Reporter examines how climate change affects a variety of plants and animals. 05.20.04

Experts debate the President's rejection of the Kyoto Treaty. 06.14.01

A study suggests that global warming is altering marine life. 03.28.01

Browse the NewsHour's coverage of environment.

NewsHour Extra:
Top Story: Global Warming Fears Lead to Ratification of Kyoto Protocol. 02.14.2005

Top Story: Rising Arctic Temperatures Lead to Global Environmental Changes 11.10.2004

Top Story: President Bush Outlines New Global Warming Plan. 02.15.02

Top Story: U.N. Study Says Earth Getting Warmer. 07.02.01

Outside Links:
Earth Day Network

EarthDay.gov

NASA

Extra is not responsible for the content of external Internet sites

Earth Day Intensifies Global Warming Debate
Posted: 04.19.06

While the U.S. government has chosen to focus on clean air, land conservation and water quality this Earth Day, an international organizing body is featuring global warming, an issue that has gained momentum in recent months.

Printer-friendly versions: PDF

Earth Day crowd in KievThe winter of 2005-2006 will go on record as one of the warmest in recent history and 2005 was the warmest year on record, according to NASA.

And although not all scientists agree, most experts studying Earth's recent climate past believe that human activities such as the release of heat-trapping gas are a dominant factor in the warming trend.

Earthday Network, Earth Day's international organizing body, has chosen to feature global warming as the theme for Earth Day, April 22, taking the issue head on and hoping to encourage activism.

Meanwhile, the Bush administration, which has been skeptical of the human influence on climate change, saying more study is needed, has designated the theme of Earth Day 2006 as "cleaning the air, promoting land conservation, and improving water quality."

What is global warming?
Reading and Discussion Questions

Across the world, people burn fossil fuels, like coal and oil, for energy. The energy created provides electricity and heat for our homes and businesses, but the burning process, called combustion, also releases gases into the air.

Some of the gases can trap heat near the Earth instead of letting it pass through the atmosphere into space. These gases are known as greenhouse gases because they reflect heat and warm the Earth the same way a greenhouse creates a warm environment for plants to grow, even in the middle of winter.

Earth seen from spaceThe most common greenhouse gas is carbon dioxide, which is an odorless, colorless and naturally occurring compound.

The question is how to measure the effect of human activity on the naturally occurring greenhouse effect, and take into account the planet's long history of rising and falling average temperatures and carbon dioxide levels.

A heated debate

The question of human impact has sparked intense debate from the scientific community to the halls of Congress.

The focus in recent years has been on climate change models that show a sharp increase in average temperature in the last 100 years after a long period of stability -- creating a graph that looks like a hockey stick.

Earth seen from spaceThe model was incorporated into the international standard for assessment of climate change, the Climate Change 2001 report produced by the U.N. Intergovernmental Panel on Climate Change.

In 2005, 11 national science academies, including those from the United States, United Kingdom, China and Russia, signed a statement renewing their support for the document, asserting that climate change is "real" and a result of human activities.

However, skeptics charge that the models forming the basis of Climate Change 2001 haven't been sufficiently scrutinized.

A 2003 report criticized the simplicity of the mathematical models used to create the "hockey stick" graph and suggested using local data instead of global averages. Skeptics say other climate change indicators account for local temperature anomalies like a Medieval Warm Period that occurred about 1,000 years ago and a Little Ice Age that ended about 100 years ago. Earth seen from space

In the U.S. Congress, Republican Representative Joe Barton of Texas, the chairman of the House Committee on Energy and Commerce, condemned the "hockey stick" research and asked for the raw data and a review of the methodology behind it.

This spurred a passionate response from the National Academies of Sciences, National Science Foundation and 20 scientists, who wrote to Barton supporting the validity of the research and its conclusion.

One of those researchers was James Hansen, NASA's leading climate scientist, who has pointed to ocean warming as the "smoking gun" for global warming. Last year, he concluded that temperatures could rise by 5 degrees Celsius over the next century. Hansen has accused the federal government of censoring him and NASA documents to align with policy.

Earth Day

Earth Day was founded in 1970 by Wisconsin Senator Gaylord Nelson, an outspoken advocate for the environment.

Earth seen from spaceThe first Earth Day was organized by grassroots organizations from across the country. Over the years these groups spread Earth Day to 174 countries, organizing events with schools, businesses and governments.

While originally started to build support for a political cause, Earth Day has been seen by many to represent a respect for the planet and a desire to care for it.

-- Compiled by Bryan Hayes and Adnaan Wasey for NewsHour Extra

Do you have a strong opinion about this article? Or do you have a personal experience related to this article that you'd like to share with our readers? Click here to submit your story.

Daily Buzz



Evan and Kamaria
Debating Financial Aid for Illegal Immigrants
American schools and financial aid should be only for legal citizens of the United States. There should be no exceptions to this.
Evan, Houston, Texas

Debating The News
My Story
Editorial Page
Poetry


Click here to find out how your essay or poem could appear on NewsHour Extra.