By IPS Correspondents
AMSTERDAM, Jul 11 1996 (IPS)

Despite recent broadsides against the Intergovernmental Panel on Climate Change’s view that human activity is changing the world’s climate for the worse, scientific evidence that this is indeed the case continues to build.

The conclusions come as the IPCC meets in Geneva with representatives of 150 nations to draft new action plans to tackle the problem.

The IPCC’s view that “the balance of evidence” suggests mankind has a “discernible” influence on global climate, has been slated by energy industry lobbyists, but also by some highly regarded scientists, notably professor Frederick R. Seitz, former president of the U.S. National Academy of Sciences.

In a recent commentary in The Wall Street Journal, Seitz said that IPCC conclusions had been expanded on after the traditional ‘peer review’ by fellow scientists, so the delivered version had the effect of deceiving policymakers into believing that evidence of human-induced climate change is stronger than it is.

Yet scientific evidence is mounting that climate change is indeed taking place. John F.B. Mitchell of the British government’s Meteorological Office in Bracknell, in Britain, has identified changes which he says are probably too big to have come entirely from natural variations.

He has used computer simulations to investigate the effects of a buildup of carbon dioxide, as well as increased production of particles from the burning of coal and oil, and the depletion of high-altitude ozone due to chemicals.

The computer simulated patterns of temperature change in the atmosphere which were very close to real patterns observed in the atmosphere from 1963 to 1987. One temperature pattern showed cooling in the upper atmosphere and warming at lower altitudes, as a result of carbon dioxide buildup, says Mitchell.

Another pattern revealed greater low-altitude warming in the Southern Hemisphere than the Northern, apparently from the shading effect of the industrially produced particles in the Northern Hemisphere.

According to Neville Nicholls at the Bureau of Meteorology Research in Victoria, Australia, Mitchell’s work is “the clearest evidence yet that humans may have affected global climate.”

Similarly scientists researching another man-made cause of environmental crisis, ozone depletion, have recently verified that ozone levels are decreasing not just over the Arctic and Antarctic but also in the tropics.

U.S. government scientists at the National Oceanic and Atmospheric Administration (NOAA) revealed last week that the ozone layer in the atmosphere over Hawaii reached a record low during the winter of 1994-95, producing one of the lowest recordings ever over a populated area.

They also confirmed that levels of harmful ultraviolet radiation increased as ozone levels dropped, resulting in a 40 percent increase in the part of the solar spectrum which causes sunburn.

“We were able to verify that as ozone goes down, UV (ultraviolet) goes up,” says David Hofmann, director of NOAA’s Climate Monitoring and Diagnostics Laboratory in Boulder, Colorado.

NOAA found that total ozone dropped 23 percent from October 1994 to December for the first time since measurements began at the Mauna Loa Observatory in Hawaii more than 30 years ago.

The scientists believe the low ozone reading in Hawaii may have been in part the result of changes in wind direction, although the long-term downward trend is probably due to man-made chemicals.

An ozone molecule, made up of three oxygen atoms, is created by the action of sunlight on the atmosphere. Most ozone is created in the tropics since those regions get the most sunlight. Normally the wind then carries the ozone to the colder regions.

Some decrease in ozone in winter is normal, but not to the extent recorded in 1994. “At first we thought something was wrong with the instrument” says Hofmann. But then researchers realised that the low followed a switch of the upper level winds from easterly to westerly.

They then looked at their records and found 12 winters in the past 31 years with ozone levels that ranged from 5 to 10 percent below the average winter value and in each case the wind had changed direction from easterly to westerly during the previous summer.

While this does not help to solve the underlying problem of a general reduction in ozone levels, it should enable scientists to predict particularly low ozone levels and issue warnings so that people can minimise exposure.

The wider question of global climate change, however, cannot be predicted so easily. “There is an urgent need for an expanded international effort,” says World Health Organisation (WHO) director general Hiroshi Nakajima.

The WHO says disturbances to natural and ecological systems caused by climate change will have many effects on human health, most of them adverse, say a joint study by the WHO, the World Meterological Organisation (WMO) and the United Nations Environment Programme (UNEP).

Many of these would affect large populations in many different regions. While direct effects include those resulting from heatwaves, storms and floods, there would also be indirect effects caused by socioeconomic disruption arising from environmental deterioration.

There would also be long term impacts on agriculture, fish stocks and patterns of disease. The geographical distribution of vector- borne diseases is also likely to change.

These include malaria which now affects 350 million people a year, Chagas disease which affects 100 million and River Blindness, affecting 17.5 million. As temperatures increase vectors such as mosquitoes could spread to new areas.

WHO estimates that the proportion of the world population at risk from malaria could increase in the next century from 45 percent to 60 percent.

Climate change may also increase the production of air pollutants while a warmer and wetter climate could increase the airborne concentration of pollens and spores in some regions leading to an increased incidence of allergic diseases.

At the same time agriculture may be affected with resulting decreases in food supply and increased malnutrition.

In addition the related problem of continuing ozone depletion may lead to increased ground-level exposure to ultra-violet radiation leading to increased skin cancer and reduced immunity.

“Health science must develop new and better methods for clarifying the relationship between public health and natural and human-induced climate change,” says WHO.

Yet the scientific row goes on. This week some 100 European and U.S. scientists issued a joint statement warning that there is still no scientific consensus on the subject of climate change.

“On the contrary, most scientists now accept the fact that actual observations from earth satellites show no climate warming whatsoever,” says the joint statement.

Group leader, Professor Helmut Metzner of the University of Tubingen, Germany, President of the European Academy for Environmental Affairs in Leipzig, says that actual temperature observations do not agree with computer models of the atmosphere.

“Based on the evidence available, we cannot subscribe to the so- called ‘scientific consensus’ that envisages climate catastrophes and advocates hasty actions,” the statement says.

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