GRABER: The air pollutant ozone is known to harm human health and
be toxic to plants. Now, it looks like ozone can also damage soil.
Researchers in Michigan conducted an experiment on two groups of
forests. One was sprayed with carbon dioxide. The other got a mix of
carbon dioxide and ozone. In the stand of trees exposed to both carbon
dioxide and ozone, the ozone reduced the ability of the soil to capture
and store carbon dioxide by half.
That’s significant because some scientists say the increase in carbon
dioxide from greenhouse gas emissions can be lessened if absorbed by
forests. But according to this new research, plants and soils that live in
areas with high levels of ozone may be significantly less able to clean
the air of CO2.
In the upper atmosphere, ozone protects against ultraviolet radiation.
But ground-level ozone forms as the result of a reaction between
chemicals from burning fossil fuels and from industrial processes and
sunlight and warm temperatures. It’s found at high levels in many parts
of the U.S. and around the world. Given the new research, nations may
have to re-evaluate their strategies to combat global warming. That’s
this week’s Note on Emerging Science. I’m Cynthia Graber.
[MUSIC: Mu-Ziq “Brace Yourself Jason” LUNATIC HARNESS
(Astralwerks - 1997)]
Stand (n)
1 : an act of stopping or staying in one place 2 a : a halt for defense or
resistance b : an often defensive effort of some duration or degree of
success <a goal-line stand> c (1) : a stop made to give a performance
<a 6-game stand at home> (2) : a town where such a stop is made
3 a : a place or post where one stands b : a strongly or aggressively held
position especially on a debatable issue 4 a : the place taken by a
witness for testifying in court b plural (1) : a section of the tiered seats
for spectators of a sport or spectacle (2) : the occupants of such seats c :
a raised platform (as for a speaker) serving as a point of vantage
5 a : a small often open-air structure for a small retail business <a
vegetable stand> <a hot dog stand> b : a site fit for business
opportunity 6 : a place where a passenger vehicle stops or parks <a taxi
stand> 7 : HIVE 2 8 : a frame on or in which something may be placed
for support 9 : a group of plants growing in a continuous area
10 : a standing posture
lessen (vi) : to shrink in size, number, or degree : DECREASE
(vt) to reduce in size, extent, or degree
1. Ozone, O3, gas, a powerful oxidizer, can effectively
oxidize contaminants and toxic materials in the soil.
So, it has been used for contaminated soil
remediation. But, we just learned that soil containing
ozone will have less ability to store CO2, leading to
more greenhouse effect. Which one is more important
on your mind? Any creative thoughts or comments
about the issue of ozone in soil?
2. Trees convert CO2 back to O2 for animals. But,
humans have destroyed a large area of forest. For
today, do you think there are enough trees in the
whole Taiwan? How about for cities such as Taipei?
3. If we want to plant more trees and give Taipei more
greens, what would be your idea? Are you going to
use the roof tops? How would you use it? Will there
be any problem?
4. Taipei city has stopped the permit of building more
houses in YangMingShan. Assume that you owned a
piece of land there and were not allowed to build, so
your land loses a lot of value, would you be very upset?
What could Taipei city do to make you happy, then?