TEXT FOR ADDITIONAL READING AND UNDERSTANDING
Global warming
For 2.5 million years the Earth's climate has fluctuated cycling from ice ages to warmer periods. But in the last century the planet's temperature has risen unusually fast - about 1.2 to 1.4 degrees Fahrenheit. Scientists believe it’s human activity that's driving the temperatures up, a process known as global warming.
Ever since the industrial revolution began factories, power plants and eventually cars have burnt fossil fuels such as oil and coal, releasing huge amounts of carbon dioxide and other gases into the atmosphere. These greenhouse gases trap heat near the Earth through a naturally occurring process called the greenhouse effect.
The greenhouse effect begins with the sun and the energy it radiates to the Earth. The Earth and the atmosphere absorb some of this energy while the rest is radiated back into space.
Naturally occurring gases in the atmosphere trap some of this energy and reflect it back warming the Earth. Scientists now believe that the greenhouse effect is being intensified by the extra greenhouse gases that humans have released. Evidence for global warming includes a recent string of very warm years. Scientists report that 1998 was the warmest year in measured history with 2005 coming in second. Meanwhile readings taken from ice core show that the greenhouse gases- carbon dioxide and methane -have hit their highest levels in the past four hundred and twenty thousand years.
Arctic sea ice is also shrinking. According to NASA studies the extent of Arctic sea ice has declined about 10 % in the last thirty years. As long as industrialized nations consume energy and developing countries increase their fossil fuel consumption, the concentration of greenhouse gases in the atmosphere will continue to rise. Researchers predict that temperatures will increase about two to ten degrees Fahrenheit by the end of the century. What’s less certain is what rising temperatures mean for the planet. Some climate models predict subtle changes. Others forecast rising sea levels which could flood coastal areas around the world. Weather patterns could change, making hurricanes more frequent. Severe droughts could become more common in warm areas and species unable to adapt to changing conditions would face extinction.
Although much remains to be learnt about global warming many organizations advocate cutting greenhouse gas emissions to reduce the impact of global warning. Consumers can help by saving energy around the house, switching the compact fluorescent light bulbs and driving fewer miles in the car each week. These simple changes may make the Earth cooler in the future.
- 1. Match the words that are used in the text:
ice |
activity |
human |
warming |
global |
revolution |
industrial |
fuels |
power |
dioxide |
fossil |
effect |
huge |
amount |
carbon |
plant |
greenhouse |
sea ice |
arctic |
changes |
NASA |
areas |
developing |
conditions |
subtle |
countries |
coastal |
light bulb |
sea |
level |
changing |
studies |
fluorescent |
age |
2. Fill in the gaps:
Emissions, extinction, flood, for the last century, human activity, models, radiated, readings, saving
- ... the planet's temperature has risen unusually fast - about 1.2 to 1.4 degrees... .
- Scientists believe that it’s … that’s driving the temperature up.
- The greenhouse effect begins with the sun and the energy ... to the Earth.
- Naturally ... gases in the atmosphere trap some of this energy and reflect it back warming the Earth.
- Meanwhile ... taken from ice core show that the greenhouse gases (carbon dioxide and methane) hit their highest level.
- Some climate ... predict subtle changes.
- Others forecast rising sea levels which could ... coastal areas around the world.
- Species unable to adapt to changing conditions would face ... .
- Many organizations advocates cutting greenhouse gas … .
- Consumers may help by … energy around the house.
- 3. Answer the following questions:
- How long has the Earth's climate fluctuated?
- How has the temperature risen in the last century?
- What is driving the temperature up?
- What is this process called?
- What do plants, factories and cars release into the atmosphere?
- What do these gases do in the Earth's atmosphere?
- What is this process called?
- What does the greenhouse effect begin with?
- What happens with energy near the atmosphere?
- Why is the greenhouse effect being intensified?
- What are the hottest years in the measured years?
- How has the extent of the arctic sea ice declined in the recent thirty years?
- What conditions will the concentration of greenhouse gases in the atmosphere continue to rise on?
- What are the scientists' predictions concerning the temperature rise?
- What does the temperature rising mean for the planet?
- What do organizations advocate?
- What can common consumers help by?