ON A spring day in 1988, while on a transatlantic flight, Stephen Schneider
read an article in the airline magazine on the high-tech future of the Netherlands.
It included a map of Holland flooded again, as it had been centuries ago,
with a caption that read ‘Flooded for recreation’. No mention was made of
the greenhouse effect.

When Schneider asked an official from the Dutch environment ministry
about the caption, he learnt that the large lake in the centre of the country
was fresh water from the Rhine river. The region would be flooded to protect
the nation’s ground water supplies from intrusion by salt water, caused
by rising sea levels. Holland’s dykes, he was told, are high enough.

Few countries have the resources or political will to plan for the greenhouse
effect as the Netherlands. Indonesia, an island nation and former Dutch
colony, for example, is moving people from more densely populated islands
into low-lying coastal areas prone to flood if sea levels rise in the future.
Canals dug in Thailand to bring fresh water to rice paddies carry sea water
inland when storms cause tidal surges.

How will the world deal with environmental refugees caused by the greenhouse
effect? What will happen to farmers displaced by the intensive agricultural
methods that will become necessary if we are to grow crops in mid-latitude
agricultural zones in our hotter future? How will the human race deal with
the changed climate in the future, brought about by its careless ways of
dealing with pollution? How will the world deal with plant pests, flies
carrying encephalitis and malarial mosquitoes as they multiply in warmer,
increasingly irrigated areas? Why should developing nations not burn their
forests when the industrial countries have already done so? Schneider, a
senior climatologist at the US’s National Center for Atmospheric Research,
says: ‘We cannot continue to use the atmosphere as a sewer without expecting
substantial and potentially irreversible global environmental disruption.’
He feels sustainable development must become our first priority.

Fifteen years ago he was concerned that his colleagues and he would
not have assembled the facts on climate before it changed. Today, most climatologists
agree the world will warm, but they often disagree on details of timing,
location and intensity. This leads to public confusion or apathy on the
greenhouse effect.

Schneider offers his experiences as ‘the most outspoken responsible
person on climate’ to point out the research, uncertainties, values and
needs in Global Warming. He takes his audience into a world of climate models,
palaeoclimatic maps (drawing future pictures of Earth based on evidence
from warmer epochs in the past), biofeedbacks, the Gaia hypothesis, oceanography,
ozone depletion, policy responses and relations with the news media. He
uses anecdotes, charts and Congressional hearing transcripts effectively
to cover every conceivable topic related to climate, placing the reader
at the heart of the important issues of global climate.

The news media earn their own chapter in his book. Schneider learnt
quickly that scientists must either deal with the process a lot, or not
at all. There is no middle ground. He is concerned that most reporters cover
complex scientific issues in the same way that they cover political reporting.
He feels this method, which he refers to, tongue in cheek, as ‘the four
D’s – drama, debate, disaster and dichotomy’, fails to inform the public
adequately on complex, critical scientific issues.

Global Warming details three methods for the human race to deal with
expected global warming: mitigation, adaptation or prevention. Schneider
is so impressed by the rapidity and strength of the greenhouse effect that
he feels prevention represents the only good course of action.

Another concern is with people selecting extremes out of context to
fit their prejudices. For seven years in the Reagan era, Schneider battled
with the Department of Energy over policy decisions based on ‘uncertain’
or ‘incomplete scientific data’. But if we demand certainty, he asks, why
take out health insurance or build nuclear weapons? When asked by a American
senator why a change of a few degrees in temperature mattered, Schneider
explains that it is not a matter of average temperatures but the frequency
and degree of extremes. A rise of 2 or 3 degrees in temperature doubles
the chances of heat waves in large cities in the US or droughts in the American
grain belt. In 1988 a drought cut yields of wheat by 40 per cent and forced
the US, the world’s leading exporter of grain, to use more grain than it
produced.

The Environmental Protection Agency in the US considers global heating
to be one of the most critical problems facing the human race. Global Warming
is an important book by one of the principal climatologists concerned with
the greenhouse effect. It offers an excellent view of the entire climate
debate and holds sufficient information to fill three books. For those who
want more, there’s an excellent bibliography. Considering the rapidity and
pervasiveness of human induced global warming and the credibility of its
author, it comes highly recommended.

ONE OF the challenges facing the human race is caused by the rapid pace
at which we are heating the Earth. Humanity is used to gradual changes in
climate. We have never experienced anything so rapid and as profound as
the global heating induced by our pollution. It is expected to cause more
changes in climate in the next century than have occurred over the entire
two million years of human history.

Recent palaeoclimatic records show that climate can change the Earth
rapidly. Newly developed techniques enable scientists to reconstruct true
pictures of fossilised remains from the bed of the sea in very deep locations
where marine worms have not blurred the results. Records of levels of oxygen
isotopes and calcium carbonate from Atlantic sediments recovered just west
of the British Isles show abrupt temperature changes at the end of the last
ice age 10 000 years ago. The quick heating was the result of climate-induced
changes in the main ocean current that travels around the world. This current
heats Europe and produces much of its weather.

The greenhouse effect spells problems for agriculture and water supplies.
A warmer world melts more polar ice, expands water and causes sea levels
to rise, inundating some of the best agricultural land in an already hungry
world. Hotter climates are expected to lower soil moisture and increase
the possibility of drought.

The biogeochemical relationships involved in global climate are very
sophisticated yet explained only minimally by the popular press to the public.
For example, a few degrees of additional heating could increase the rate
of decay of organic carbon in plant remains buried in the ground, ultimately
releasing even more greenhouse gases to the atmosphere.

The Natural Resources Defense Council, an American environmental organisation,
has produced The Challenge of Global Warming to improve public understanding
of the complex issue around which climate policy is built. This book presents
the current state of global initiatives including the initial scientific
consensus reached at Villach, Austria, in 1985, the policy statement from
the Toronto conference of 1988 – where several nations resolved to cut emissions
of carbon dioxide worldwide by 20 per cent by the year 2005 and the US Congress’s
assessment of depletion of ozone in the stratosphere.

Climate scientists contributed papers to the book that had been prepared
as testimonies to the US Congress on the causes, effects, policy options
and related costs of global climate warming. Together, these chapters give
an effective presentation of unique material seldom seen by the public.
There are some excellent graphs and charts as well. The reader quickly understands
the massive changes that global warming will bring and how unprepared the
human race is to deal with it. Although most of the data presented come
from the US, the book’s message affects everyone.

* 1718 Connecticut Avenue, NW, Suite 300, Washington DC 20009.

Jack Miller, a freelance writer based in Denver, Colorado, specialises
in writing about the environment.

THE MAN who first predicted that the greenhouse effect could warm our planet in the coming decades now says that the warming is beneficial and should be encouraged. He envisages cattle grazing in what is now the Sahara desert and crops growing in arid parts of central Asia.

Mikhail Budyko, the Soviet Union’s leading climatologist, will play a key role in one of the working groups of the UN’s Intergovernmental Panel on Climatic Change, chaired by the Soviet Union. The panel is currently preparing advice for the world’s politicians on the likely effects of global warming.

Unlike most Western climatologists, Budyko dismisses fears that the centres of continents, such as the grain belts of the American Midwest and the Ukraine, will dry out. Any drying will be temporary, he says, and will give way to wetter times and bumper harvests by the middle of the next century, provided that global warming is allowed to continue. ‘Limiting carbon fuel consumption will be not only useless, but even dangerous,’ he told a recent scientific meeting in the West.

As concern about the greenhouse effect has grown, Western scientists have developed increasingly sophisticated computer models of climate, known as general circulation models, to make their predictions of how the world will change.

Soviet scientists have taken a different approach. Budyko and his colleagues have developed the science of palaeoclimatology. Researchers reconstruct past climates from studies of fossil remains, such as tree rings and pollen. These reconstructed climates serve as analogues to predict what will happen in the future.

Until the intervention of humans, the world’s climate had been slowly cooling over the past 6000 years. Following a cycle that has repeated itself perhaps 20 times in the past 2 million years, the planet warmed abruptly after the peak of the most recent ice age, 18 000 years ago. It reached a warm phase between 8000 and 6000 years ago before starting to cool again in a slow descent towards the next ice age.

This most recent warm era is known as the ‘climatic optimum’ and is the most immediate analogue for our coming greenhouse world. Palaeoclimatologists from both the West and East agree that deserts were more or less absent at that time. Crocodiles and hippopotamuses wallowed in vast wadis in the centre of what is now the Sahara desert.

The scientific debate is about which of two competing trends are likely to dominate in a warmer world . Monsoons in the climatic optimum were more intense, bringing monsoon rains further towards the centres of continents. But hotter climates also intensify the evaporation of moisture from soils, causing them to dry out.

Most climatologists in the West believe that the desiccation of soils will predominate, especially in middle latitudes where most of the world’s grain crops grow. They predict that America’s ‘breadbasket’ will become a dust bowl and suggest that the droughts of the past two years in the Midwest are a sign of things to come.

Budyko believes that in the Sahara, extra rain will more than compensate for the effects of desiccation. He cites past climates as crucial evidence. He believes that there will be an ‘enormous increase’ in precipitation in the Sahara, perhaps before the end of the 1990s. He predicts an increase of rainfall in the Sahara of 30 centimetres – enough to allow nomadic peoples to colonise the desert with cattle. He also predicts up to 50 per cent more rain in the arid lands of central Asia than at present. This would bring new hope for the Aral Sea in the Soviet Union, which has been drying up because farmers are taking too much water from its tributaries.

In an interview for Climate and Man, a television programme that is to be broadcast this Sunday in Britain, Budyko says: ‘Climate catastrophe is not probable for the future because the main idea about such a catastrophe is connected with the idea of aridisation of continents. The great majority of continents will be in a better condition of moisture.’

He predicts that an initial drying in the American Midwest will be replaced by the middle of the next century, as warming continues, by wetter conditions. ‘Deserts should disappear in the future,’ he says. ‘In warm epochs there was no desert.’ Ten million years ago, before the start of the ice ages and before the emergence of human beings, Africa was covered by forests. Now, says Budyko, ‘paradise can return’.

‘Global warming is a good thing,’ he says. ‘It will increase harvests everywhere.’ The Soviet Union and Canada will flourish most, he says. ‘These two countries have enormous areas which are very difficult for productive agriculture because they are too cold.’ English people are, he says, ‘probably are very lucky. England is one of probably a very limited number of countries in which no considerable climatic change will take place.’

Budyko was one of the first scientists to warn about the greenhouse effect more than 20 years ago. ‘At the very beginning of this problem, I think I was in a minority of one . . . nobody believed in such a possibility,’ he says. ‘It contradicted many, let us not say scientific facts, but scientific superstitions. The opposition was enormous. If I was not bold enough to ignore this opposition, quite possibly scientific development would not be exactly the same as we have now.’ Now, he says, ‘my position is rather conservative’.

The cracks in sea ice, known as ‘leads’, are up to 500 metres wide.
Russ Schnell and his colleagues discovered them while using high-resolution
lidars, or laser radars, which operate in the near infrared. They observed
plumes of water vapour rising as high as 4 kilometres.

Schnell says that the leads are created when prevailing winds cause
stress in the sea ice. This may open as many as 20 to 50 leads in each area
of 100 square kilometres.

The researchers were able to measure the number and size of the leads.
‘We can now detect both open and frozen leads remotely,’ says Schnell. ‘This
allows us to fly an aircraft across the arctic basin at 400 miles per hour
and find out how many leads are – or were – recently open’.

As water vapour rises from these leads, it forms ice crystals. Schnell
claims the crystals are important in cleansing the boundary layer of the
atmosphere, the layer just above the sea. ‘Most air pollution readings taken
in the Arctic undermeasure actual values observed above the boundary layer
by a factor up to 100,’ says Schnell.

In a report to be published in Annals of Glaciology, Judith Curry, an
atmospheric scientist at Purdue University, Indiana, suggests that this
water vapour forms low-level clouds of ice crystals that reflect heat out
of the atmosphere and keep surface ice cooler. Although these ice clouds
cannot be seen by satellites or at night, Curry feels that they play an
effective role in delaying the seasonal warming of the arctic ice cap. She
suggests that they may alter the polar heating which climatologists predict
because of the greenhouse effect.

Current climate scenarios assume less energy and water vapour rising
from ice sheets and much less arctic cloud cover in winter than the new
evidence shows. The low-level ice clouds may also provide some clue to the
depletion of ozone in the troposphere. Every spring, at polar sunrise, the
tropospheric ozone is totally destroyed. Both Schnell and Curry claim a
possible link between high-rising ice crystals and ozone destruction. Curry
suggests that chemical reactions on the surface of these ice crystals remove
reactive nitrogen compounds, thus enhancing chlorine and bromine species
which react with ozone (Nature, vol 334, p 138).

Both scientists recommend further studies of ice crystals and water
droplets in the lower arctic atmosphere as an accessible laboratory on the
chemistry of ozone destruction.

In the experiment, Charles Czeisler and his colleagues exposed people,
during the middle of their subjective night, to light intensities normally
found outdoors in the early morning or afternoon. By exposing their subjects
to bright light on two nights, they were able to adjust the original circadian
rhythm by 80 to 85 per cent. With a third night’s exposure to light, the
researchers were able to reset the circadian pacemaker by up to 12 hours.

Light intensity and timing were the keys to the success of the experiment.
Czeisler and his colleagues discovered that, at night, people were 4.5 times
as sensitive to light as during the day. It was this that enabled the researchers
to make their adjustments to the human circadian clock in such a short time.
The researchers used light with an intensity between 7000 and 12 000 lux,
which is comparable to light found outdoors in the early morning. In earlier
experiments, researchers used light at indoor intensities.

According to Richard Kronauer, an applied mathematician with the group:
‘Every eight-fold increase in light intensity doubles the circadian pacemaker’s
response.’ To move the biological clock forward, a subject should be exposed
to bright light after the middle of subjective night. If they are exposed
to light before, however, the clock shifts backwards. The researchers found
that the colour of the light seems to have no major effect. Kronauer also
cites one test in which a single eight-hour exposure to bright light, centred
on midnight, produced the same shift in circadian rhythms that the group
usually obtained from two five-hour nightly exposures.

Kronauer recommends that travellers reset their internal clocks by one
to two hours per day by using daylight or commercially available light boxes.
He also recommends that people flying from New York to London take daytime
flights and look out of the window instead of watching the film. People
flying in the opposite direction should take afternoon flights and arrive
before dark. Taking night flights to save money ‘might prove a poor economy’.