mittee eventually exonerated Glenn in August,
- Known for his honesty and ethical standards,
he later referred to this controversy as the lowest
point in his life. In the aftermath of the “Keating af-
fair,” Glenn defeated his Republican opponent in
the 1992 Senate election by a wide margin. He con-
sidered running for a fifth term but announced in
February, 1997, that he would retire from the Senate
at the end of his fourth term, an unprecedented
record for a U.S. senator representing Ohio.
During the 1990’s, Glenn supported America’s
space program as the United States joined other na-
tions to create an International Space Station (ISS)
for joint scientific research. He expressed a strong
desire to participate as a crew member of one of
the space shuttles flying to the ISS. Then in his sev-
enties, he believed that the experience of an older
person in space might assist the study of aging and
possible effects on the body. Few took him seriously
at first, but he continued his determined efforts to
gain approval. Finally, the National Aeronautics
and Space Administration (NASA) announced in
early 1998 that he would return to space. Glenn be-
came a payload specialist assigned to undertake
physiological tasks and other experiments on the
STS-95 space shuttleDiscover y(launched on Octo-
ber 29 and returned to Earth on November 7,
1998).
Another focus was Glenn’s involvement in estab-
lishing the John Glenn Institute for Public Service
and Public Policy at the Ohio State University in - The institute encouraged students to aca-
demically train in preparation for public-service ca-
reers.
Impact John Glenn’s career in public service re-
veals a deep appreciation for his country. This con-
tinued during the 1990’s as a member of the U.S.
Senate. His 1998 shuttle flight reaffirmed his long
interest in space technology. His support for the
John Glenn Institute for Public Service and Public
Policy also showed his commitment to utilize his tal-
ents and experience to expand opportunities for
others who seek to serve their nation. Glenn has
been an inspiration to many Americans.
Further Reading
Glenn, John, and Nick Taylor.John Glenn: A Memoir.
New York: Bantam Books, 1999.
Green, Robert.John Glenn: Astronaut and U.S. Senator.
Chicago: Ferguson, 2001.
Montgomery, Scott, and Timothy R. Gaffney.Back in
Orbit: John Glenn’s Return to Space. Atlanta: Long-
street Press, 1998.
Taylor StultsSee also Bondar, Roberta; Elections in the United
States, 1992; Lucid, Shannon; Space exploration;
Space shuttle program. Global warming debate
Definition Controversy about a worldwide
environmental problemHuman-induced warming of the Earth’s climate emerged
as a major scientific, social, political, and economic issue
during the 1990’s, as the effects of climate change became
evident in ever yday life in locations as varied as small is-
land nations of the Pacific Ocean and the shores of the Arc-
tic Ocean.For the past two and a half centuries, at an accelerat-
ing rate, the basic composition of Earth’s atmo-
sphere has been materially altered by the fossil-fuel
emissions of human industry. Industry and trans-
port have been emitting increasing amounts of
greenhouse gases, including carbon dioxide and
methane, which, along with various other synthetic
chemicals, retain heat near the surface, contribut-
ing to significant warming.Changes in the Atmosphere The proportion of car-
bon dioxide, the most important of these gases, rose
from 280 parts per million (ppm) in about 1880 to
roughly 365 ppm in 1999 (and 383 ppm in 2007).
Methane’s preindustrial range in the atmosphere
was 320 to 780 parts per billion (ppb); by 1999, that
level had risen to about 1,700 ppb, a steeper rise, in
proportional terms, than carbon dioxide. Carbon
dioxide is two hundred times more plentiful in the
atmosphere than methane, but a molecule of meth-
ane can retain twenty-five times as much heat as one
of carbon dioxide.
Global temperatures spiked in the late 1980’s and
1990’s, repeatedly breaking records set only a year or
two earlier. The warmest year in recorded history to
that time was 1998, breaking the record set in 1996,
which exceeded 1995’s new benchmark. According
to the National Aeronautics and Space Administra-
tion (NASA) Goddard Institute for Space Studies,374 Global warming debate The Nineties in America