--------------------------------------- #1 Sky has shrunk by five miles, say scientists
By Aisling Irwin, Science Correspondent
THE sky is shrinking and has been doing so for the past 40 years, scientists have discovered.
About five miles of sky have been lost since 1958, and that figure may double over the next century. Researchers studying the Earth's upper atmosphere, 56 miles up, said the contraction is probably a result of the greenhouse effect. They reassured people yesterday that it is unlikely to do us any harm.
Dr Martin Jarvis, of the British Antarctic Survey in Cambridge said: "Nothing nasty is going to happen." But he said the change was a dramatic reminder that global warming is having profound consequences.
The Earth's atmosphere is divided into several zones, the uppermost of which is the thermosphere. Interspersed within the thermosphere is the little-known ionosphere, composed mainly of ionised gases. The ionosphere is studied by bombarding it with radio wave pulses from below, in a technique similar to the echo-sounders used on ships to study the ocean floor.
The new study, which probed 38 years of data gathered at the Antarctic peninsula and the Falkland Islands, reveals for the first time that the shrinkage is global, said Dr Jarvis, who worked with scientists from the Rutherford Appleton Laboratory in Oxfordshire. The work is published in the Journal of Geophysical Research.
The effect is believed to be the result of carbon dioxide build-up. At lower altitudes the gas acts like a blanket, causing the Earth to heat up. This is because it absorbs infra-red rays and reflects some of them back down on to the Earth.
But when carbon dioxide accumulates in the thermosphere, the gas siphons heat away, absorbing infra-red and reflecting much of it into space, where it is lost. As a result, it cools and the pressure then drops, which causes the ionosphere to shrink. Variations in the thermosphere can be up to 100 times greater than at ground level, and it can therefore be used as a sensitive litmus test of global change. Dr Jarvis said: "The drop in altitude is not in itself harmful to people. It is, however, another warning signal about what changes to the atmosphere can be caused by human impact."
© Copyright Telegraph Group Limited 1998. T -----------------------------------------------
#2 No strategy on global warming despite floods
Mexico: Mexicans are stranded by deadly floods, millions of Bangladeshis are left homeless and threatened by disease, rare rhinos are decimated by rains in India. The manifestations of climate change are widespread and ominous, but governments still cannot agree on a strategy to combat global warming.
People in Chiapas State, Mexico, set out on foot this week in search of help rather than wait for a slow trickle of aid, even as President Ernesto Zedillo said his government had the situation under control.
Men, women and children walked in some cases for more than a day, crossing rain-swollen rivers, muddy swamps and dense jungle to arrive at emergency shelters set up along the battered Pacific coast of Mexico's southernmost state.
Many of them mourned family members lost to gushing torrents and mudslides which killed at least 400 people and left some 850 missing, according to a government report. A week of downpours dumped 2,000mm (780 inches) of rains in the country's southernmost point, about half average annual rainfall.
Yet rescue efforts continued to be a challenge. Continuing rains along the coast slowed helicopter airlifts for a third day in a row, adding to the despair of tens of thousands of people still cut off from overland routes by flooding in the impoverished state.
Along the Xelaju river soldiers armed with pickaxes and shovels worked to unearth the bodies of those who relatives feared did not escape the flood waters in time.
The floods have left an estimated 100,000 people homeless.
Meanwhile in Bangladesh, Dhaka authorities employed thousands of extra workers to clean up the city as floods receded to leave mounds of stinking rubbish which pose a new health hazard.
The floods, which left millions homeless out of Bangladesh's 120 million people, have claimed 1,000 lives and caused widespread devastation to agriculture, industry and transport networks.
Makeshift homes have sprung up to house the homeless, and emergency food aid is arriving at the country's ports to be delivered to the victims of the floods, which covered two-thirds of Bangladesh.
The health department said some 225,000 people were suffering from diarrhoea and other water-borne diseases; 200 have died from the illness.
In Tokyo delegates from more than 20 major developed and developing countries ended a two-day meeting yesterday with no fresh agreements on ways to combat global warming. However, delegates said the closed-door ministerial conference played an instrumental role in maintaining the "momentum" gained last November in Kyoto.
The Tokyo conference was held to lay a groundwork for an annual UN conference on climate change scheduled to be held in Buenos Aires in November.
In Kyoto last December a gathering of 159 countries agreed on cutting greenhouse gas emissions. The conference agreed that developed nations should cut emission of carbon dioxide and other "greenhouse" effects.
In India tigers and other animals living in Kaziranga national park in Assam state were threatened by floods, the Worldwide Fund for Nature (WWF) said yesterday.
© Copyright: The Irish Times
--------------------------------------------------------
#3 Scientists in Britain Say Sky May Be Shrinking
Outer Atmosphere Has Fallen 5 Miles
By Joby Warrick
Washington Post Staff Writer
Thursday, September 17, 1998; Page A03
Chicken Little may have been right: The sky appears to be falling, or at least shrinking. And global warming may be to blame.
British scientists reported yesterday that the Earth's upper atmosphere contracted or dropped by nearly five miles in the past four decades -- a decline they suggest is linked to "greenhouse gas" pollution on land.
The long-term change in the Earth's outer "thermosphere" is apparently harmless, and, in fact, is barely noticeable against the daily ballooning and shrinking in the volatile outermost zone of the atmosphere. But researchers from the British Antarctic Survey said the shift appears to be another signal that human activity is profoundly influencing the planet's climate.
"The closest you can get to explaining this phenomenon is greenhouse gases," said Martin Jarvis, an atmospheric research physicist in Cambridge, England, and the lead author of the report.
The findings, published in the September issue of the Journal of Geophysical Research, are based on 38 years of atmospheric measurements from research stations in the Falkland Islands and Antarctica. The data record changes in the thermosphere -- the outer layer of the atmosphere that extends to roughly 300 miles above Earth -- by tracking the rise and fall of the ionosphere, a region of free electrons within the thermosphere that reflects certain kinds of high-frequency radio waves.
The hottest and windiest part of the atmosphere, the thermosphere roasts by day as the sun's energy pushes temperatures as high as 800 degrees. The heating causes the thermosphere to expand by scores of miles and then contract at night. The amount of expansion varies according to seasonal cycles as well as long-term changes in the Earth's magnetism and in solar intensity.
But even after accounting for those fluctuations, Jarvis and his colleagues discovered that the thermosphere was in a long-term retreat. Compared with measurements from the late 1950s, the zone had "shrunk" by about 5 miles -- an indication that the thermosphere is cooling.
What does this cooling and shrinking have to do with global warming? Plenty, Jarvis said. Cooling in the upper atmosphere is one of the widely predicted consequences of global warming. In computer simulations of the so-called greenhouse effect, carbon dioxide and other gases trap heat near the Earth's surface while causing the upper atmosphere to cool, and therefore contract.
Jarvis called the finding "not a shattering result, but another indicator that things are changing." Earlier, less ambitious studies in Europe also detected a contraction in the thermosphere, while a report earlier this month by two Indian scientists was unable to confirm the trend.
The British scientist stressed, though, that the five-mile drop in altitude "is not in itself harmful to people."
"It is however, another warning signal about what damage to the atmosphere can be caused by human impact," he said.
Jarvis conceded there could be alternative explanations for the trend, including a long-term change in the sun's intensity. So far, he said, scientists have not detected a shift in solar patterns large enough to account for the change in the thermosphere.
Other scientists described the finding as interesting but said more research was needed to rule out other possible causes.
"It does seem to be a noisy signal that we're trying to read," said Arthur Thomas, an atmospheric physicist and senior scientist at the National Center for Atmospheric Research in Boulder, Colo. "People at different locations have found different kinds of effects. We're still not 100 percent clear that we've pinned down the science."
Sagging Layer
British scientists say the atmospheric layer called the "thermosphere" has dropped nearly five miles in the past 40 years, possibly because of "greenhouse gas" pollution.
SPACE SHUTTLE'S typical orbit: Above 150 miles
MOST METEORS burn up at about 60 miles
TYPICAL JETLINER Cruises at about 6.5 miles (34,320 feet)
CUMULUS CLOUDS 0.85 miles (4,500 feet)
SOURCE: British Antarctic Survey
© Copyright 1998 The Washington Post Company
--------------------------------------- #4 Climate experts seek long-term view By Miguel Llanos
It may seem ironic, what with all the White House concern about climate change, but a new federal report said the United States lacks a sound system for researching long-term patterns. And without one, it concluded, man cannot expect to understand the future effects of global warming. A key problem, say some
scientists, is that the federal budget structure rarely allows for long-term research since it works on a year-to-year basis.
In a report by the National Research Council, a panel of experts added that striving for long-term predictions is required if man is ever to limit the damage of floods, storms and droughts to agriculture, people and property.
The complexities of climate change make reliable long-term predictions that much harder, the researchers said. But even so, they added, a better system for long-term climate research is needed.
A national program, they added, would be a "first step" towards that end. "Informed stewardship of the Earth's resources for the generations to come must draw on the insights offered by model predictions and extrapolations of observations that can give us a glimpse of the future."
The need is all the greater because of the debate around global warming. Many experts - and national governments - believe it is partly caused by humans who burn fossil fuels, cut down forests and release chemicals into the atmosphere. Others believe man plays little or no role in what they see as natural climate change.
MIT oceanographer Carl Wunsch is among those climate scientists who feel the "major problem" is that the government "has no mechanism for supporting long-term measurements of the climate system.
"To a very great extent, this is the most difficult of all climate issues," he claimed. "We need decades of data but have no means of funding its acquisition."
It's not so much a question of blaming the White House or Congress, he added. "It's not that simple, government agencies generally have a short-term view, in part because they operate on annual funding cycles," he said. "No one has the job of worrying about problems 20 years out. There's no government infrastructure to support true climate research."
The study by the NRC, itself a federal agency, said researchers have been able to improve predictions up to a year out. Rainfall in northwestern Europe and western North America can be predicted months in advance, to some degree, it noted.
And experts now know about El Nino, the Pacific Ocean current blamed for
causing droughts, floods and other weather disruptions every few years.
But it's the long-term picture where little progress has been made, the experts added, and where more attention is needed because climate "has changed, is changing and will continue to do so" with or without human influences.
"In 1992 and 1993 ice cores approximately 1.8 miles long were extracted from the heart of the Greenland ice sheet, revealing changes in the Earth's climate system over the last 150,000 years or so," the national team of experts noted in the report released Tuesday.
"One of the most remarkable revelations of these cores was the fact that the climate in the Holocene (the past 10,000 years) - a period that we might consider representative of our modern climate conditions - has undergone considerable natural variation."
And in modern times, the report said, much milder extremes have had huge effects - witness the devastating Midwest floods in 1993 and 1997.
-------------------------------------
#5 Global Temperatures Hit New High for 8th Straight Month
Associated Press Friday, September 11, 1998; Page A24
August was the eighth month in a row to set a new average high temperature worldwide, federal officials said yesterday.
The average global temperature for August was 61.4 degrees Fahrenheit, the National Oceanic and Atmospheric Administration reported. That broke the previous record of 61.1 degrees set in 1997 and is 1.3 degrees above the long-term average of 60.1 degrees for August.
August "continued the unprecedented string of record-breaking temperatures," the agency said. "Each month this year has set new all-time record global near-surface temperatures."
For the year to date, the average global temperature of 58.5 degrees Fahrenheit was also 1.3 degrees above the long-term average of 57.2 degrees.
That average is based on data from 1880 to 1997, according to NOAA.
During August, surface warmth was evident over much of the globe, with cool areas in Europe, Alaska, Siberia, Bangladesh, the South Atlantic and the Central Pacific, the agency said.
In the Central Pacific, sea surface temperatures were below normal, an event commonly referred to as La Niña, although ocean temperatures off the northwest coast of South America remained warm.
In the United States, January through August has been the fifth-wettest and fourth-warmest such period on record.
For the year to date, the nation has had an average of 22.77 inches of precipitation. The normal for the period is 20.05 inches. The wettest January-through-August period was in 1979, with 23.34 inches of precipitation.
The year 1934 had the warmest January through August for the United States, with a record 56.9 degrees. In 1998, the temperature for the period was 56.2 degrees. The normal for January through August is 54.3 degrees.
© Copyright 1998 The Associated Press -------------------------------------- #6 August was the warmest ever globally
Friday, September 11, 1998
This past August will go down
in the books as the warmest
August on record globally, the
National Oceanic and
Atmospheric Administration
said Thursday.
The average global temperature
for the month was 61.4 degrees
Fahrenheit, which is 1.3
degrees above the long term
mean temperature of 60.1
degrees. The previous record
for August was 61.1 degrees set
in 1997.
For the year to date the average
global temperature of 58.5
degrees was also 1.3 degrees above the long term mean of 57.2.
During August, surface warmth was evident over much of the globe, with
cool areas in Europe, Alaska, Siberia, Bangladesh, the South Atlantic, and
the central Pacific.
In the central Pacific, sea surface temperatures were below normal,
commonly referred to as La Niña, although ocean temperatures off the
northwest South American coast remained warm.
Nationally, January through August has been the fifth wettest and fourth
warmest on record. For the year to date, the nation has had 22.77 inches
of precipitation. The normal for the period is 20.05 inches. The wettest
January through August was in 1979, with 23.34 inches of precipitation.
The year 1934 was the warmest January through August with a record
56.9 degrees. In 1998, the temperature for the period was 56.2 degrees.
The normal for January through August is 54.3 degrees.
Regionally, in the West it was the wettest January through August on
record. The West had 20.88 inches of precipitation, compared with a
normal of 10.33 inches. Other regions in the upper 10 percent of the
wettest years on record were the Northeast, East, north Central, Central
and the Northwest.
In the Northeast, it was the warmest January through August on record,
with an average temperature of 50.9 degrees. The normal for the region is
47.3 degrees. Other regions in the upper 10 percent of all years on record
were the east-north Central, Central, South and Northwest.
The outlook for the fall and winter 1998-99 includes periods with
enhanced probabilities of below normal precipitation in the Southwest,
central Plains, and southeastern United States, with above normal
precipitation in the Northwest.
Conditions are expected to be considerably more variable than the
relatively stable and warmer than normal conditions experienced last
winter. This outlook is consistent with La Niña conditions, which are
expected to continue developing in the central Pacific.
Copyright 1998, Environmental News Network, All Rights
Reserved
-- http://www.netcomuk.co.uk/~jones_m/frontline.htm