Last year was the hottest in earth’s recorded history, scientists
reported on Friday, underscoring scientific warnings about the risks of runaway
emissions and undermining claims by climate-change contrarians that global
warming had somehow stopped.
Extreme heat blanketed Alaska and much of the western United States last year.
Several European countries set temperature records. And the ocean surface was
unusually warm virtually everywhere except around Antarctica, the scientists
said, providing the energy that fueled damaging Pacific storms.
In the annals of climatology, 2014 now surpasses 2010 as the warmest year in a
global temperature record that stretches back to 1880. The 10 warmest years on
record have all occurred since 1997, a reflection of the relentless planetary
warming that scientists say is a consequence of human emissions and poses
profound long-term risks to civilization and to the natural world.
Of the large inhabited land areas, only the eastern half of the United States
recorded below-average temperatures in 2014, a sort of mirror image of the
unusual heat in the West. Some experts think the stuck-in-place weather pattern
that produced those extremes in the United States is itself an indirect
consequence of the release of greenhouse gases, though that is not proven.
Several scientists said the most remarkable thing about the 2014 record was that
it occurred in a year that did not feature El Niño, a large-scale weather
pattern in which the ocean dumps an enormous amount of heat into the atmosphere.
Longstanding claims by climate-change skeptics that global warming has stopped,
seized on by politicians in Washington to justify inaction on emissions, depend
on a particular starting year: 1998, when an unusually powerful El Niño produced
the hottest year of the 20th century.
With the continued heating of the atmosphere and the surface of the ocean, 1998
is now being surpassed every four or five years, with 2014 being the first time
that has happened in a year featuring no real El Niño pattern. Gavin A. Schmidt,
head of NASA’s Goddard Institute for Space Studies in Manhattan, said the next
time a strong El Niño occurs, it is likely to blow away all temperature records.
“Obviously, a single year, even if it is a record, cannot tell us much about
climate trends,” said Stefan Rahmstorf, head of earth system analysis at the
Potsdam Institute for Climate Impact Research in Germany. “However, the fact
that the warmest years on record are 2014, 2010 and 2005 clearly indicates that
global warming has not ‘stopped in 1998,’ as some like to falsely claim.”
Such claims are unlikely to go away, though. John R. Christy, an atmospheric
scientist at the University of Alabama in Huntsville who is known for his
skepticism about the seriousness of global warming, pointed out in an interview
that 2014 had surpassed the other record-warm years by only a few hundredths of
a degree, well within the error margin of global temperature measurements.
“Since the end of the 20th century, the temperature hasn’t done much,” Dr.
Christy said. “It’s on this kind of warmish plateau.”
NASA and the other American agency that maintains long-term temperature records,
the National Oceanic and Atmospheric Administration, issued separate data
compilations on Friday that confirmed the 2014 record. A Japanese agency had
released preliminary information in early January showing 2014 as the warmest
year.
The last scientific group that curates the world’s temperature record, in
Britain, is scheduled to report in the coming weeks.
“Why do we keep getting so many record-warm years?” Dr. Schmidt asked in an
interview. “It’s because the planet is warming. The basic issue is the long-term
trend, and it is not going away.”
February 1985 was the last time global temperatures fell below the 20th-century
average for a given month, meaning that no one younger than 30 has ever lived
through a below-average month.
The contiguous United States set its temperature record in 2012. But, mainly
because of the unusual chill in the East last year, 2014 was only the 34th
warmest year on record for the lower 48 states.
That cold was brought into the interior of the country by a loop in a current
called the jet stream that allowed Arctic air to spill southward. But an
offsetting kink allowed unusually warm tropical air to settle over the West,
large parts of Alaska and much of the Arctic.
A few recent scientific papers say that such long-lasting kinks in the jet
stream have become more likely because global warming is rapidly melting the sea
ice in the Arctic, disturbing longstanding weather patterns. But many leading
scientists are not convinced on that point.
Whatever the underlying cause, last year’s extreme warmth in the West meant that
Alaska, Arizona, California and Nevada all set temperature records. Some parts
of California had basically no winter last year, with temperatures sometimes
running 10 or 15 degrees above normal for the season.
Those conditions exacerbated the severe drought in California, which has been
alleviated only slightly by recent rains. Some small towns have run out of
water, the sort of impact that scientists fear will become commonplace as global
warming proceeds in the coming decades.
WASHINGTON (AP) -- The world isn't just getting hotter from man-made global
warming, it's getting stickier. It really is the humidity. The amount of
moisture in the air near the surface -- the stuff that makes hot weather
unbearable -- increased 2.2 percent in just under three decades. And computer
models show that the only explanation is man-made global warming, according to a
study published in Thursday's journal Nature.
''This humidity change is an important contribution to heat stress in humans as
a result of global warming,'' said Nathan Gillett of the University of East
Anglia in the United Kingdom, a co-author of the study.
Gillett studied changes in specific humidity, which is a measurement of total
moisture in the air, between 1973-2002. Increases in humidity can be dangerous
to people because it makes the body less efficient at cooling itself, said
University of Miami health and climate researcher Laurence Kalkstein. He was not
connected with the research.
Humidity increased over most of the globe, including the eastern United States,
said study co-author Katharine Willett, a climate researcher at Yale University.
However, a few regions, including the U.S. West, South Africa and parts of
Australia were drier.
The finding isn't surprising to climate scientists. Physics dictates that warmer
air can hold more moisture. But Gillett's study shows that the increase in
humidity already is significant and can be attributed to gas emissions from the
burning of fossil fuels.
To show that this is man-made, Gillett ran computer models to simulate past
climate conditions and studied what would happen to humidity if there were no
man-made greenhouse gases. It didn't match reality.
He looked at what would happen from just man-made greenhouse gases. That didn't
match either. Then he looked at the combination of natural conditions and
greenhouse gases. The results were nearly identical to the year-by-year
increases in humidity.
Gillett's study followed another last month that used the same technique to show
that moisture above the world's oceans increased and that it bore the
''fingerprint'' of being caused by man-made global warming.
Climate scientists have now seen the man-made fingerprint of global warming on
10 different aspects of Earth's environment: surface temperatures, humidity,
water vapor over the oceans, barometric pressure, total precipitation,
wildfires, change in species of plants in animals, water run-off, temperatures
in the upper atmosphere, and heat content in the world's oceans.
''This story does now fit together; there are now no loose ends,'' said Ben
Santer, a scientist at Lawrence Livermore National Lab and author of the
September study on moisture above the oceans. ''The message is pretty compelling
that natural causes alone just can't cut it.''
The studies make sense, said University of Victoria climate scientist Andrew
Weaver, who was not part of either team's research.
It will only feel worse in the future, Gillett said. Moisture in the air
increases by about 6 percent with every degree Celsius (1.8 degrees Fahrenheit),
he said. Using the Intergovernmental Panel on Climate Change's projections for
temperature increases, that would mean a 12 to 24 percent increase in humidity
by the year 2100.
''Although it might not be a lethal kind of thing, it's going to increase human
discomfort,'' Willett said.
WASHINGTON (AP) -- The number of tropical storms developing annually in the
Atlantic Ocean more than doubled over the past century, with the increase taking
place in two jumps, researchers say.
The increases coincided with rising sea surface temperature, largely the
byproduct of human-induced climate warming, researchers Greg J. Holland and
Peter J. Webster concluded. Their findings were being published online Sunday by
Philosophical Transactions of the Royal Society of London.
An official at the National Hurricane Center called the research ''sloppy
science'' and said technological improvements in observing storms accounted for
the increase.
From 1905 to 1930, the Atlantic-Gulf Coast area averaged six tropical cyclones
per year, with four of those storms growing into become hurricanes.
The annual average jumped to 10 tropical storms and five hurricanes from 1931 to
1994. From 1995 to 2005, the average was 15 tropical storms and eight hurricanes
annually.
Even in 2006, widely reported as a mild year, there were 10 tropical storms.
''We are currently in an upward swing in frequency of named storms and
hurricanes that has not stabilized,'' said Holland, director of mesoscale and
microscale meteorology at the National Center for Atmospheric Research in
Boulder, Colo.
''I really do not know how much further, if any, that it will go, but my sense
is that we shall see a stabilization in frequencies for a while, followed by
potentially another upward swing if global warming continues unabated,'' Holland
said.
It is normal for chaotic systems such as weather and climate to move in sharp
steps rather than gradual trends, he said.
''What did surprise me when we first found it in 2005 was that the increases had
developed for so long without us noticing it,'' he said in an interview via
e-mail.
Holland said about half the U.S. population and ''a large slice'' of business
are ''directly vulnerable'' to hurricanes.
''Our urban and industrial planning and building codes are based on past
history,'' he said. If the future is different, ''then we run the very real risk
of these being found inadequate, as was so graphically displayed by (Hurricane)
Katrina in New Orleans.''
Hurricanes derive their energy from warm ocean water. North Atlantic surface
temperature increased about 1.3 degrees Fahrenheit during the 100-year period
studied. Other researchers have calculated that at least two-thirds of that
warming can be attributed to human and industrial activities.
Some experts have sought to blame changes in the sun. But a recent study by
British and Swiss experts concluded that ''over the past 20 years, all the
trends in the sun that could have had an influence on the Earth's climate have
been in the opposite direction to that required to explain the observed rise in
global mean temperatures.''
As the sea surface temperatures warm, they cause changes in atmospheric wind
fields and circulations, and these changes are responsible for the changes in
storm frequency, Holland said.
Chris Landsea, science and operations officer at the National Oceanic and
Atmospheric Administration's National Hurricane Center, said the study is
inconsistent in its use of data.
The work, he said, is ''sloppy science that neglects the fact that better
monitoring by satellites allows us to observe storms and hurricanes that were
simply missed earlier. The doubling in the number of storms and hurricanes in
100 years that they found in their paper is just an artifact of technology, not
climate change.''
But Kerry Emanuel, a hurricane expert at Massachusetts Institute of Technology,
said the study was significant. ''It refutes recent suggestions that the upward
trend in Atlantic hurricane activity is an artifact of changing measurement
systems,'' said Emanuel, who was not part of the research team.
Improvements in observation began with aircraft flights into storms in 1944 and
satellite observations in 1970. The transitions in hurricane activity that were
noted in the paper occurred around 1930 and 1995.
''We are of the strong and considered opinion that data errors alone cannot
explain the sharp, high-amplitude transitions between the climatic regimes, each
with an increase of around 50 percent in cyclone and hurricane numbers,'' wrote
Webster, of Georgia Institute of Technology, and Holland.
The research was funded by the National Science Foundation.
Global warming is an "unequivocal" fact and is likely to continue
for centuries, the leading international body studying climate change said in a
report today.
It is "very likely" - a probability of more than 90% - that the
phenomenon has been caused by human activity, the Intergovernmental Panel on
Climate Change (IPCC) concluded in its fourth report.
In 2001, the body - which brings together 2,500 scientists from more than 30
countries - said global warming was "likely", or 66% probable, to have been
caused by humans.
Today's report predicted that global average temperatures would rise by between
1.1C and 6.4C (2-11.5F) by 2100 - a slightly broader range than in the 2001
findings.
However, it said the best estimate was for increases of between 1.8C and 4C. In
comparison, the world is currently around 5C warmer than during the last ice
age. The report predicts a rise of between 18cm and 58cm in sea levels by the
end of this century, a figure that could increase by as much as 20cm if the
recent melting of polar ice sheets continues.
The 21-page summary of the findings, called Climate Change 2007: The Physical
Science Basis, was formally agreed by the IPCC in Paris yesterday.
It steers clear of policy recommendations, instead providing a rigorously
scientific assessment of the likely risks.
"Warming of the climate system is unequivocal, as is now evident from
observations of increases in global average air and ocean temperatures,
widespread melting of snow and ice, and rising global mean sea level," the
summary said.
It added that greenhouse gases were already responsible for a series of existing
problems, including fewer cold days, hotter nights, intense heatwaves, floods
and heavy rains, droughts and an increase in the strength of hurricanes and
tropical storms.
The scale of such phenomena in the 21st century "would very likely be larger
than those observed during the 20th century", it said, warning that no matter
how much humanity reduces greenhouse gas emissions, global warming and sea level
rises would continue for hundreds of years.
"This is just not something you can stop. We're just going to have to live with
it," co-author Kevin Trenberth, the director of climate analysis for the
US-based National Centre for Atmospheric Research, said.
"We're creating a different planet. If you were to come up back in 100 years,
we'll have a different climate."
However, the scientists stressed this did not mean governments should accept the
inevitable.
"The point here is to highlight what will happen if we don't do something and
what will happen if we do something," another co-author, Jonathan Overpeck, of
the University of Arizona, said.
"I can tell if you will decide not to do something, the impacts will be much
larger than if we do something."
The head of the US delegation to the body said the report was a "comprehensive
and accurate" presentation of the science.
Sharon Hays, the associate director of the White House office of science and
technology policy, claimed George Bush's policy of slowing a rise in emissions
rather than cutting them was working.
"The president has put in place a comprehensive set of policies to address what
he has called the serious challenge of climate change," she told Reuters.
Climate change activists have lambasted Mr Bush for pulling out of the Kyoto
protocol on greenhouse gas emissions, which he said was ineffective and harmful
to the US economy. Instead, he has focused on investments in technologies such
as hydrogen and biofuels.
The effects of man-made emissions of carbon dioxide are being felt on every
inhabited continent in the world with very different parts of the climate now
visibly responding to human activity.
These are among the main findings of the most intensive study of climate change
by 2,000 of the world's leading climate scientists. They conclude that there is
now little doubt that human activity is changing the face of the planet.
In addition to rising surface temperatures around the world, scientists have now
linked man-made emissions of greenhouse gases to significant increases in ocean
temperatures, rises in sea levels and the dramatic melting of Arctic sea ice
over the past 35 years.
A draft copy of the fourth report of the Intergovernmental Panel on Climate
Change (IPCC) says that global temperature rises this century of between 2C and
4.5C are almost inevitable. Ominously, however, it also says that much higher
increases of 6C "or more" cannot be ruled out.
The final version of the IPCC's latest report is to be published on Friday but a
draft copy, seen by The Independent, makes it clear that climate change could be
far worse than previously thought because of potentially disastrous "positive"
feedbacks which could accelerate rising temperatures.
A warmer world is increasing evaporation from the oceans causing atmospheric
concentrations of water vapour, a powerful greenhouse agent, to have increased
by 4 per cent over the sea since 1970. Water vapour in the atmosphere
exacerbates the greenhouse effect. This is the largest positive feedback
identified in the report, which details for the first time the IPCC's concern
over the uncertainties - and dangers - of feedback cycles that may quickly
accelerate climate change.
All the climate models used by the IPCC also found that rising global
temperatures will erode the planet's natural ability to absorb man-made CO2.
This could lead to CO2 concentrations in the atmosphere rising by a further 44
per cent, causing global average temperatures to increase by an additional 1.2C
by 2100.
The IPCC's Fourth Assessment Report will go further than any of its three
previous reports in linking the clear signs of global climate change with
increases in man-made emissions of CO2 and other greenhouse gases since the
start of the Industrial Revolution.
"Confidence in the assessment of the human contributions to recent climate
change has increased considerably since the TAR [Third Assessment Report]," says
the draft report. This is due to the stronger signs of climate change emerging
from longer and more detailed records and scientific observations, it says.
The "anthropogenic signal" - the visible signs of human influence on the climate
- has now emerged not just in global average surface temperatures, but in global
ocean temperatures and ocean heat content, temperature extremes on the land and
the rapidly diminishing Arctic sea ice. "Anthropogenic warming of the climate
system is widespread and can be detected in temperature observations taken at
the surface, in the free atmosphere and in the oceans," the draft report says.
"It is highly likely [greater than 95 per cent probability] that the warming
observed during the past half century cannot be explained without external
forcing [human activity]."
The report adds that global warming over the past 50 years would have been worse
had it not been for the counterbalancing influence of man-made emissions of
aerosol pollutants, tiny airborne particles that reflect sunlight to cause
atmospheric cooling. "Without the cooling effect of atmospheric aerosols, it is
likely that greenhouse gases alone would have caused more global mean
temperature rise than that observed during the last 50 years," the draft report
says.
"The hypothetical removal from the atmosphere of the entire current burden of
anthropogenic sulphate aerosol particles would produce a rapid increase of about
0.8C within a decade or two in the globally averaged temperature."
The IPCC says that over the coming century we are likely to see big changes to
the Earth's climate system. These include:
* Heat waves, such as the one that affected southern Europe in summer 2003, are
expected to be more intense, longer-lasting and more frequent.
* Tropical storms and hurricanes are likely to be stronger, with increased
rainfall and higher storm surges flooding coastlines.
* The Arctic is likely to become ice free in the summer, and there will be
continued melting of mountain glaciers, ice caps and ice sheets.
* Sea levels will rise significantly even if levels of CO2 are stabilised. By
2100 sea levels could be 0.43 metres higher on average than present, and by 2300
they could be up to 0.8 metres higher.
The IPCC also finally nails the canard of the climate sceptics who argue that
global warming is a myth or the result of natural climate variability; natural
factors alone cannot account for the observed warming, the IPCC says. "These
changes took place at a time when non-anthropogenic forcing factors (i.e. the
sum of solar and volcanic forcing) would be expected to have produced cooling,
not warming.
"There is increased confidence that natural internal variability cannot account
for the observed changes, due in part to improved studies demonstrating that the
warming occurred in both oceans and atmosphere, together with observed ice mass
losses."
The report, the first draft of which was formulated last year, will be made
public on Friday in Paris.
Key findings of the IPCC's fourth assessment report
* Global temperatures continue to rise with 11 of the 12 warmest years since
1850 occurring since 1995. Computer models suggest a further rise of about 3C by
2100, with a 6C rise a distant possibility
* It is virtually certain (there is more than a 99 per cent probability) that
carbon dioxide levels and global warming is far above the range of natural
variability over the past 650,000 years
* It is virtually certain that human activity has played the dominant role in
causing the increase of greenhouse gases over the past 250 years
* Man-made emissions of atmospheric aerosol pollutants have tended to counteract
global warming, which otherwise would have been significantly worse
* The net effect of human activities over the past 250 years has very likely
exerted a warming influence on the climate
* It is likely that human activity is also responsible for other observed
changes to the Earth's climate system, such as ocean warming and the melting of
the Arctic sea ice
* Sea levels will continue to rise in the 21st Century because of the thermal
expansion of the oceans and loss of land ice
* The projected warming of the climate due to increases in carbon dioxide during
the 21st Century is likely to cause the total melting of the Greenland ice sheet
during the next 1,000 years, according to some computer forecasting models
* The warm Gulf Stream of the North Atlantic is likely to slow down during the
21st Century because of global warming and the melting of the freshwater locked
up in the Greenland ice sheet. But no models predict the collapse of that warm
current by 2100.
A study by the world's
leading experts
says global warming
will happen faster
and be more devastating
than previously
thought
Sunday January 21, 2007
The Observer
Robin McKie,
science editor
Global warming is destined to have a far more destructive and
earlier impact than previously estimated, the most authoritative report yet
produced on climate change will warn next week.
A draft copy of the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change, obtained by The Observer, shows the
frequency of devastating storms - like the ones that battered Britain last week
- will increase dramatically. Sea levels will rise over the century by around
half a metre; snow will disappear from all but the highest mountains; deserts
will spread; oceans become acidic, leading to the destruction of coral reefs and
atolls; and deadly heatwaves will become more prevalent.
The impact will be catastrophic, forcing hundreds of millions of
people to flee their devastated homelands, particularly in tropical, low-lying
areas, while creating waves of immigrants whose movements will strain the
economies of even the most affluent countries.
'The really chilling thing about the IPCC report is that it is
the work of several thousand climate experts who have widely differing views
about how greenhouse gases will have their effect. Some think they will have a
major impact, others a lesser role. Each paragraph of this report was therefore
argued over and scrutinised intensely. Only points that were considered
indisputable survived this process. This is a very conservative document -
that's what makes it so scary,' said one senior UK climate expert.
Climate concerns are likely to dominate international politics next month.
President Bush is to make the issue a part of his state of the union address on
Wednesday while the IPCC report's final version is set for release on 2 February
in a set of global news conferences.
Although the final wording of the report is still being worked on, the draft
indicates that scientists now have their clearest idea so far about future
climate changes, as well as about recent events. It points out that:
· 12 of the past 13 years were the warmest since records began;
· ocean temperatures have risen at least three kilometres beneath the surface;
· glaciers, snow cover and permafrost have decreased in both hemispheres;
· sea levels are rising at the rate of almost 2mm a year;
· cold days, nights and frost have become rarer while hot days, hot nights and
heatwaves have become more frequent.
And the cause is clear, say the authors: 'It is very likely that [man-made]
greenhouse gas increases caused most of the average temperature increases since
the mid-20th century,' says the report.
To date, these changes have caused global temperatures to rise by 0.6C. The most
likely outcome of continuing rises in greenhouses gases will be to make the
planet a further 3C hotter by 2100, although the report acknowledges that rises
of 4.5C to 5C could be experienced. Ice-cap melting, rises in sea levels,
flooding, cyclones and storms will be an inevitable consequence.
Past assessments by the IPCC have suggested such scenarios are 'likely' to occur
this century. Its latest report, based on sophisticated computer models and more
detailed observations of snow cover loss, sea level rises and the spread of
deserts, is far more robust and confident. Now the panel writes of changes as
'extremely likely' and 'almost certain'.
And in a specific rebuff to sceptics who still argue natural variation in the
Sun's output is the real cause of climate change, the panel says mankind's
industrial emissions have had five times more effect on the climate than any
fluctuations in solar radiation. We are the masters of our own destruction, in
short.
There is some comfort, however. The panel believes the Gulf Stream will go on
bathing Britain with its warm waters for the next 100 years. Some researchers
have said it could be disrupted by cold waters pouring off Greenland's melting
ice sheets, plunging western Europe into a mini Ice Age, as depicted in the
disaster film The Day After Tomorrow.
The report reflects climate scientists' growing fears that Earth is nearing the
stage when carbon dioxide rises will bring irreversible change to the planet.
'We are seeing vast sections of Antarctic ice disappearing at an alarming rate,'
said climate expert Chris Rapley, in a phone call to The Observer from the
Antarctic Peninsula last week. 'That means we can expect to see sea levels rise
at about a metre a century from now on - and that will have devastating
consequences.'
However, there is still hope, said Peter Cox of Exeter University. 'We are like
alcoholics who have got as far as admitting there is a problem. It is a start.
Now we have got to start drying out - which means reducing our carbon output.'
For decades, the arrival of the first V-shaped
flights of Bewick's swans in Britain's wetlands after a 2,000-mile journey from
Siberia heralded the arrival of winter.
This year, a dramatic decline in numbers of the distinctive yellow-billed swans
skidding into their winter feeding grounds could be the harbinger of a more
dramatic shift in weather patterns: global warming. Ornithologists at the main
reserves that host the birds, the smallest of Britain's swans, said only a
handful had appeared on lakes and water courses. Normally, there would be
several hundred.
The latest arrival in a decade of Britain's seasonal influx of 8,000 Bewick's
swans throws into sharp relief the debate on the effects of climate change as it
enters a crucial week. As the Government's forthcoming Climate Bill is
finalised, Sir Nicholas Stern, a former World Bank economist, is expected to
warn in a report on Monday that failure to tackle global warming will provoke a
recession deeper than the Great Depression.
But far from Westminster, the potential ecological impact of the same phenomenon
was being noted in the absence of the high-pitched honking call of Bewick's
swans on reservoirs and wetlands from the Ouse to the Severn estuary. The
Wildfowl and Wetlands Trust (WWT) said its first three birds had arrived at its
Slimbridge reserve in Glouc-estershire, only on Thursday, the latest arrival
since 1995.
In Welney, Cambridgeshire, where there are normally 100 Bewick's by the end of
October as the vanguard for a winter population of 1,000; a solitary male was
this week the sole representative. The Royal Society for the Protection of Birds
said that two of its reserves in East Anglia which host the bulk of the British
population - the Ouse Washes and Nene Washes - were also devoid of Bewick's.
Experts said that the slow arrival was due to warmer than usual conditions on
the continent, in particular the birds' other main wintering grounds in the
Netherlands, and an absence of the north-east winds that aid their migration
from the Arctic tundra of northern Russia.
The disruption to the swans' migration pattern fits into an emerging pattern of
fluctuating numbers of bird species and population movements blamed on climate
change. Redwings, another winter visitor to the British Isles, started arriving
from Scandinavia only this week. Normally, they come in early September.
Other species which normally leave Europe for the winter, such as the blackcap,
are now staying through the year. The WWT and other bird conservation groups
said that it would take weeks to assess whether the late arrival of the
Bewick's, named after the 18th-century English engraver and ornithologist Thomas
Bewick, would affect the overall numbers wintering in Britain.
Since reaching a peak of about 9,000 in 1992, numbers of the swans have fallen
by about 5 per cent. In 2004, numbers of wintering ducks, geese, swans and
wading birds fell to the lowest level for a decade.
