The warmest year of this century, based on land and ocean surface
temperature data, reports a team of scientists from the National Oceanic and
Atmospheric Administration's National Climatic Data Center in Asheville, N. C.
Led by the center's Senior Scientist Tom Karl, the team analyzed temperatures from
around the globe during the years 1900 to 1997 and back to 1880 for land areas. For
1997, land and ocean temperatures averaged three-quarters of a degree Fahrenheit
above normal. (Normal is defined by the mean temperature, 61.7 degrees F, for the
30-years 1961-90.) The 1997 figure exceeds the previous record warm year, 1990, by
0.15 degrees Fahrenheit.
The record-breaking warm conditions of 1997 continues the pattern of very warm global
temperatures. Nine of the past eleven years have been the warmest on record.
"Land temperatures did not break the previous record set in 1990, but 1997 was one of
the five warmest years since 1880," said Karl. Including 1997, the top ten warmest
years over the land have all occurred since 1981, and the warmest five years all since
1990. Land temperatures for 1997 averaged three-quarters of a degree above normal,
falling short of the 1990 record by one-quarter of a degree. Ocean temperatures during
1997 also averaged three-quarters of a degree above normal, which makes it the
warmest year on record, exceeding the previous record warm years of 1987 and 1995
by 0.3 of a degree Fahrenheit.
With the new data factored in, global temperature warming trends now exceed 1.0
degree Fahrenheit per 100 years, with land temperatures warming at a somewhat
faster rate. "It is likely that the sustained trend toward increasingly warmer global
temperatures is related to anthropogenic increases in greenhouse gases," Karl said.
GLOBAL WARMING: SPRING ARRIVING EARLIER Satellites Show Global Warming May Be Changing The Seasons
A new study of satellite photos shows that between 1981 and 1991, plants in northern climates started their springtime spurt of growth a full week earlier, and that global warming may be responsible. For migratory birds and other animals that depend on the timing of plants for food, this change could have deadly consequences.
The report, based on an analysis of satellite data, shows dramatic changes in plant growth across a vast swath of the Northern Hemisphere. In the 10 years from 1981 to 1991, the start of the plant growth cycle that accompanies the spring thaw appeared to leap ahead by an average of eight days. The cause is unknown, but the timing "is consistent with an enhanced greenhouse effect caused by the build-up of . . . gases in the atmosphere," said the report by Boston University climatologist Ranga Myneni and four colleagues. (Wash. Post, 4/17/97)
OZONE LOSS TIED TO RISE IN ULTRAVIOLET
Excerpted from the New York Times, August 4, 1996 WASHINGTON, Aug, 3 (AP) - Ultraviolet radiation which causes skin cancer and cataracts in humans, has increased over large regions of the earth in the last 15 years as ozone in the atmosphere has decreased, a new study says.
Ozone, found in the atmosphere between the earth's surface and altitude of 37 miles, absorbs much of the sun's radiation. But it is depleted through complex chemical reactions, some from man-made chlorofluorocarbons used in refrigeration, electronics and insulating materials.
The ozone depletion has been sharply reduced in recent years through international agreements curbing chlorofluorocarbon emissions. But the new study, based on analysis of data from an instrument that is flown aboard NASA'S Nimbus-7 satellite, found that the annual average amount of UV-B, the portion of the ultraviolet spectrum that causes the most damage, had increased at a rate of 9.9 percent a decade at the southernmost parts of Argentina and Chile.
The rate of increase has been about 4 percent a decade for areas near the United States-Canadian border, and 6.8 percent for Britain, Germany, Russia and Scandinavia.
"The increases are largest in the middle and high latitudes, where most people live and where the majority of the world's agricultural activity occurs," said Dr. Jay R. Herman, an atmospheric scientist at the National Aeronautics and Space Administration's Goddard Space Flight Center in Maryland.
Scientists consider the risks of further increases in ultraviolet radiation to be serious. Long-term exposure to UV-B from the sun is associated with two kinds of skin cancer - basal cell and squamous cell carcinomas - and is responsible for other harmful effects in humans, to the skin, the eyes and the immune system. It also harms some crops and interferes with marine life.
RECORD OZONE DEPLETION OBSERVED IN NORTH
Excerpted from the New York Times, March 13, 1996
GENEVA, March 12 (Reuters) - The ozone layer was briefly depleted by a record 45 percent this winter over an area stretching from Greenland to western Siberia, the World Meteorological Organizations said today.
But the United Nations agency said the decline in the earth's protective layer over roughly one-third of the Northern Hemisphere did not constitute an ozone hole, as exists over Antarctica.
The average ozone deficiency over the northern region from mid-January through early March was 20 to 30 percent, the agency said, but for a few days, "an unprecedented deficiency of 45 percent" was observed.
Temperatures that fell to minus 108 degrees Fahrenheit facilitated the formation of polar stratospheric clouds that in the presence of chlorine and bromine compounds, brought about the severe ozone destruction, the meteorological agency said.
The ozone layer is a protective shield that blocks most of the sun's ultraviolet radiation.
'95 IS HOTTEST YEAR ON RECORD AS THE GLOBAL TREND RESUMES excerpted from
The New York Times,
January 4th, 1996
by William K. Stevens
The earth's average surface temperature climbed to a record high last year, according to preliminary figures, bolstering scientists' sense that the burning of fossil fuels is warming the climate...
Dr. James E. Hansen, the director of the Goddard center, predicted last year that a new global record would be reached before 2000, and yesterday he said he now expected that "we will still get at least a couple more" by then.
Dr. Hansen has been one of only a few scientists to maintain steadfastly that a century-long global warming trend is being caused mostly by, a belief he reiterated yesterday.
Other experts would go no further than the recent findings of a United Nations panel of scientists in attributing the continuing and accelerating warming trend to human activity - specifically the emission of heat-trapping gases like carbon dioxide, which is released by the burning of coal, petroleum products and wood.
The United Nations panel concluded, for the first time, that the observed warming is "unlikely to be entirely natural in origin" and that the evidence"suggests a discernible human influence on climate."
OZONE DECAY IN '95 IS UNPARALLELED
From The New York Times, Nov. 29, 1995
VIENNA, Nov. 28, 1995 (Reuters) -
The hole in the earth's ozone shield, which filters out cancer-causing ultraviolet rays, covered an area twice the size of Europe at its seasonal peak in October and grew at an unprecedented rate in 1995, the United Nations said today.
The United Nations World Meteorological Organization said the ozone hole over the Antarctic began to expand earlier than usual this year.
There was "about 1 percent per day ozone decline during the entire month of August," the organization said in a statement.
"This caused the ozone hole to expand more rapidly than in previous years," reaching a maximum of 7.7 million square miles, it said.
The ozone shield's depletion lets more of the sun's ultraviolet rays reach the earth's surface, where it can damage crops and cause skin cancer as wellas cataracts in humans.
A World Meteorological Organization expert, Rumen Bojkov, speaking at a preparatory meeting for a top-level ozone conference here, said ozone depletion in 1995 was unprecedented.
"The ozone loss at the end of November over Antarctica continues making the ozone hole phenomenon of 1995 the longest-lasting on record," he said.
The New York Times,
October 25, 1995
U.N. WARNS AGAINST DELAY IN CUTTING CARBON DIOXIDE EMISSIONS
Delaying action to rein in emissions of heat-trapping atmospheric gases like carbon dioxide could increase the rate and magnitude of future climatic changes and make the world more vulnerable to costly and possibly irreversible damages, a United Nations scientific panel says in a new report. . . An average increase in global temperature of 1.5 to 6.3 degrees by the year 2100, predicted by a third working group, would cause a sea level rise of 6 to 37 inches by then and more in the following centuries, according to the report issues yesterday. Many low-lying coastal areas around the world could be inundated, the scientists say. An average rose of about 39 inches, they say, could place 70 million people at risk.
The panel also said climate changes could produce, among other things, these consequences:
* Bring an increase in heat waves, floods, droughts, fires and pest outbreaks in some regions.
* Lead to the disappearance of entire forest types.
* Make desert climates more extreme.
* Cause a rise in the number of heat-related deaths and illnesses.
* Increase the range of vector-borne infectious diseases like malaria, yellow fever, dengue fever and viral encephalitis.
The report says that if existing technology were applied strictly, energy savings of about 25 percent could be achieved in homes, businesses and industrial plants during the next 30 years, and that greenhouse-gas reductions could be even larger.
It said energy use by motor vehicles could be cut by about a third during the same period by using efficient drive trains, light weight materials and low-air resistance design. Further restrictions could come if vehicles were made smaller.
THE NEW YORK TIMES
WEDNESDAY, SEPT 13, 1995
GENEVE, Sept 12 (Reuters) - The biggest hole ever measured in the Earth's protective ozone layer has formed over Antarctica, United Nations experts said today.
The United Nations World Meteorological Organization said that the ozone hole covers 3.86 million square miles, an area about the size of Europe. It said that figures compiled by the agency and national monitoring centers in the Southern Hemisphere showed that ozone levels had declined 10 percent in August from last year's level, the previous record low.
The ozone decline, an annual feature of Southern Hemisphere spring, was also the most rapid on record at1 percent a day, the agency said.
Romen Bojkov, a special adviser to the meteorological agency, said at a news conference that the trend reinforced arguments for reduction in emission of ozone-destroying methyl bromide. International agreements already in effect require the phasing out of other ozone-destroying chemicals.
The ozone layer absorbs and blocks most ultraviolet rays coming from the Sun. Any sustained surge in radiation reaching the Earth, scientist say, will lead to an increase in cancer in humans and animals and a reduction in crop yields, and could affect global food production.
Mr. Bojkov said the ozone hole, although changing shape according to winds, could not move far from its central position over the largely uninhabited southern polar region. But it could touch the tip of South America at Tierra del Fuego.
Over Europe and North America, ozone has declined by 10 percent since the late 1950's which means that about 15 percent more radiation is reaching the surface.
"The problem is that the effect is cumulative," Mr. Bojkov said. "It is not dangerous at the moment but could be depending on how long these conditions continue."
The latest finding confirmed predictions by the meteorological agency's experts last year that despite actions by many governments to cut emissionof gases that destroy ozone, the problem would get worse before the situation begins to improve.
Under international agreements in 1985 and 1987, countries agreed to phase out by 1999 the use of chlorofluorocarbons, ozone-destroying compounds usedas aerosols and refrigeration. They later moved the date up to the end of this year, and agreed to start phasing out methyl bromide, which is used infarming.
THE NEW YORK TIMES
FRIDAY, JULY 28, 1995
The American Lung Association announced a study showing that smog standardshave been violated hundreds of times this summer in at least 28 states, including New York, New Jersey and Connecticut. The association pointed out that the violations have occurred while Congress is debating whether to weaken public health safeguards and relax enforcement of clean air controls.
"Recent science has shown that ozone pollution causes health problems at levels well below the current Federal health standards," said Dr. AlfredMunzer at a news conference held by the association.