Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate 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:
In-depth Coverage

The Global Warming Debate

U.N. panel says humans are 'very likely' causing global warming.

02.02.07


Businesses call for the government to take action on climate change.
01.22.07

Experts discuss the continuing debate over climate change. 08.04.06


Browse the NewsHour's coverage of environment and science.

NewsHour Extra:

Top Story: World Leaders Reconvene to Discuss Global Warming Goals
11.15.06


Top Story:
Earth Day Intensifies Global Warming Debate 04.19.06


Top Story: Rising Arctic Temperatures Lead to Global Environmental Changes 11.10.04


Lesson Plan:
Are the World's Weather and Climate Changing?

Outside Links:
Intergovernmental Panel on Climate Change

National Oceanic & Atmospheric Association

Extra is not responsible for the content of external Internet sites

Global Warming Linked to Humans, New Report Says
Posted: 02.05.07

Using the strongest language yet, the world's top climate scientists released a report last week blaming humans for global warming.

Printer-friendly version: PDF

Map of projected global warmingThe Intergovernmental Panel on Climate Change (IPCC), made up of more than 2,500 scientists from over 130 nations, said it is "very likely" -- or more than 90 percent probable -- that human activity, such as the burning of fossil fuels, has caused the Earth's temperature to rise.

"Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level," the scientists said in the report.

Projected global changes

Burning fossil fuels such as coal, natural gas and crude oil creates carbon dioxide gas, a "greenhouse gas" that traps heat below the Earth's atmosphere, warming the planet like a plant hothouse.

Reading and Discussion Questions

According to the report, the temperature on the Earth will likely increase about 3.5 degrees to 8 degrees Fahrenheit by 2050 if the concentration of carbon dioxide doubles pre-industrial levels, as expected.

Even moderate increases in global temperatures would likely greatly impact ecosystems, water supplies and agricultural production.

Ice shelf at the Bay of Whales (NOAA)Northern areas will see more precipitation while semi-arid, subtropical regions will see even more drought and less rain, the New York Times reported.

With this climate change will come increasingly extreme weather events, such as heat waves, droughts and floods, the report predicted.

According to the report, sea levels are expected to rise between 7 inches and 23 inches in the 21st century -- and could be higher if ice sheets in Antarctica and Greenland melt.

Impact on humans

More water could immerse low-lying islands, and flood the coastal zones of countries like Bangladesh and cities such as Shanghai, China, and Buenos Aires, Argentina.

And changing weather patterns could cause droughts and floods in Africa and Asia.

"If you're living in parts of tropics and they're getting drier and you're a farmer there are some acute issues associated with even small changes in rainfall -- changes we're already seeing are significant," Susan Solomon, the co-leader of the team that wrote the report's summary and an atmospheric scientist for the National Oceanic and Atmospheric Administration, told the New York Times.

Flooding in Bangladesh (USAID)"If you're an Inuit and you're seeing your sea ice retreating already that's affecting your lifestyle and culture."

And those impacted most greatly will be the poorest of the poor.

"But it is the poor, in Africa and developing small island states and elsewhere, who will suffer the most, even though they are the least responsible for global warming," UN Secretary-General Ban Ki-moon told world environmental ministers meeting in Kenya Monday.

The UN leader has been charged with finding a replacement for the Kyoto Protocol, a treaty aimed at cutting greenhouse gases, which expires in 2012.

Reducing emissions

Scientists believe that global warming will increase even if humans reduce harmful greenhouse gas emissions. But reducing emissions is essential to minimizing the impact.

Smoke stacks"If we don't bring the emissions under control, we can expect potentially very, very much greater changes than what we have already seen. So to use maybe an unfortunate metaphor, this is just the tip of the iceberg compared to what may be in store for us in the future," Michael Oppenheimer, a member of the UN climate change panel and a contributor to the report, told the NewsHour.

This initial report is expected to be followed by three others, including one that will provide recommendations on how to mitigate the impact of the expected climate change.

--Compiled by Annie Schleicher for NewsHour Extra

Do you have an 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



NewsHour
Students From Around the US Debate Gun Control
I think we've been witnessing violence for years, whether in reality through the media or through video games, and I don't think that's a first-hand effect.
Ellie, Student Reporting Labs

Debating The News
My Story
Editorial Page
Poetry


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