Global Warming Is Real Many Scientists Agree Skepticism Dies Down as Computers Model Real Changes

By Robert C. Cowen, writer of The Christian Science Monitor | The Christian Science Monitor, October 1, 1995 | Go to article overview

Global Warming Is Real Many Scientists Agree Skepticism Dies Down as Computers Model Real Changes


Robert C. Cowen, writer of The Christian Science Monitor, The Christian Science Monitor


Prophets of global warming are winning new respect from skeptical scientists. Subtle changes in weather patterns that conform to predictions of improved computer-climate simulations strongly suggest that man-made climate change is upon us.

As one former skeptic, Thomas Karl, puts it: "I think there's a likelihood that the changes we see are not just due to natural variability. There is a human component."

These changes include such effects as a greater share of precipitation coming in winter and more precipitation coming in extreme events, more severe warm-season droughts, an increase in above-normal temperatures, and a decrease in day-to-day variability in temperature in parts of the Northern Hemisphere.

The draft of a new assessment by the Intergovernmental Panel on Climate Change (IPCC) likewise concludes that the observed 0.5 degree C rise in average global temperature over the past 135 years "is unlikely to be entirely due to natural causes."

Dr. Karl - a senior scientist with the National Climatic Data Center in Asheville, N.C. - says that right now, we're at a point where a majority of scientists in the field believe there may be a global-warming signal. But many are not yet willing to say that it is an obvious signal. He expects that to change to a near-consensus in favor of global warming within five years if present weather trends continue.

Michael MacCracken, with the United States Global Change Research Program office in Washington, makes a similar point. He says the evidence is "quite compelling" that heat-trapping so-called greenhouse gases and the cooling effect of man-made aerosols are affecting climate. Yet it is so far not enough to convict human activity of climate change "beyond all reasonable doubt."

Man-made cooling

The most important of these aerosols are sulfates emitted by such sources as coal- and oil-fired power plants. Like particles from volcanoes, they block sunshine and cool the lower atmosphere. Computer models had trouble simulating past climate trends in this century - let alone predict the future - when they took account only of the buildup of such greenhouse gases as carbon dioxide and methane. But when aerosols are included, the simulations become much more realistic.

For example, this was the key to temperature changes that puzzled James Hansen, Makiko Sato, and Reto Ruedy at the Goddard Institute for Space Studies in New York. The average daily maximum temperature over land rose by 0.28 degrees C between 1951 and 1990. Average minimum temperature rose 0.84 degrees - three times as much. Yet computer models with only carbon dioxide forcing predicted the same warming day and night. To match both the long-term 0.5 degree C global warming and the observed changes in daily maximum and minimum temperatures, the researchers had to include the cooling influences of aerosol pollution and increases in mid-level cloudiness. …

The rest of this article is only available to active members of Questia

Sign up now for a free, 1-day trial and receive full access to:

  • Questia's entire collection
  • Automatic bibliography creation
  • More helpful research tools like notes, citations, and highlights
  • Ad-free environment

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Global Warming Is Real Many Scientists Agree Skepticism Dies Down as Computers Model Real Changes
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

    Already a member? Log in now.