1. What's Happening to Global Climate?
We're Changing Our Climate! Who Can Doubt It?
- B Y SIMON RETALLACK AND PETER BUNYARD -
The reality of human-induced climate change is now beyond question. While
certain vested interests and elements of the mass media like creating the impression of an ongoing debate, in truth, there is an overwhelming consensus
among scientists that human-induced climate change is happening.
The facts are indisputable. First, take the physics of gases such as carbon dioxide, methane, nitrous oxide and CFCs: they are radiatively active - they trap heat in the Earth's atmosphere. So, i f you put heat-trapping gases up into the atmos phere, through the burning of fossil fuels and the destruction of natural forests, you will trap heat. And that, of course, is precisely what humans have been doing with particular zeal since the indus trial revolution of the mid-19th century - no one denies that emis sions and consequently atmospheric greenhouse concentrations have been soaring for decades. As a consequence, it should come as no surprise that humans are heating the planet.
Official confirmation came in 1995, when the Inter-Govern mental Panel on Climate Change (IPCC) - the official scientific body established in 1988 by the UN to investigate climate change - published its Second Assessment Report, written and reviewed by some 2,000 scientists. It stated that "the balance of evidence suggests there is a discernible human influence on global cli mate."1
A consensus now undeniably exists that human-induced cli mate change is real and has to be tackled. In the words of the then Chair of the IPCC, Bert Bolin, "Al l the summaries [of the IPCC] have been agreed at the plenary meetings without dissent and none of us has received any subsequent letters of complaint from scien tists regarding the final version. The process provides justification for the description of substantial scientific consensus."2 As James McCarthy, chairman of the Scientific Committee for the Interna tional Biosphere Programme, moreover, declares: "There is no debate among any statured scientists [i.e. those currently engaged in relevant research and whose work has been published in the refereed scientific journals] about what is happening."3
A consensus now undeniably exists that human-induced climate change is real and has to be tackled.
The relationship between greenhouse gases and climate that has now been established is supported by evidence from isotopic studies of ice-core material from both Antarctica and Greenland. The evidence shows that every period of global cooling has gone hand-in-hand with a drop in both carbon dioxide and methane in the atmosphere, and every time the planet has thawed, a surge has taken place in those same gases.4
The climat e i s changing before our very eyes Rising temperatures are already the clearest sign of climate change. So far, according to the IPCC, global average tempera tures have risen 0.6°C above the pre-industrial average. Nine of
the hottest years on record have occurred since 1988; six of the first eight months of 1998 were the warmest since records began in 1866; and July 1998 was the hottest month ever. According to the IPCC's latest coupled ocean-atmosphere models, i f emissions continued to rise on current trends, greenhouse gas concentrations would reach double pre-industrial levels - higher than for several million years - by 2080. Were this so, we would see a global aver age increase of 2.5°C, with perhaps 4°C over land masses, partic ularly in the northern high latitudes, 3°C to 4°C over parts of the Arctic or Antarctic, and possibly substantial regional variations from the global average. I f the increases in temperature seem modest, it should be noted that a 3°C cooling brought on the most recent ice age. What is more, the climatologists of the IPCC pre dict that i f emissions continued to rise on current trends, a second doubling of pre-industrial levels of CO2 could lead to a cata strophic rise of around 10°C. Even these predictions may under state the speed and scale of change (see 'Misreading the Models', p75). The destabilising effect of planetary warming upon our climate systems is already being felt. Over the past decade, worldwide, we have seen virtually every climate record broken since reliable record-taking began a century ago.
The implications for life are immense. With higher tempera tures, there is more energy driving the Earth's climatic systems, which in turn causes more violent weather events. Severe storms, floods, droughts, dust storms, sea surges, crumbling coastlines, salt water intrusion of groundwater, failing crops, dying forests, the inundation of low-lying islands, and the spread of endemic dis eases such as malaria, dengue fever and schistosomiasis is on the cards i f the consumption of fossil fuels is not phased out. Agricul ture worldwide would face severe disruption and economies could tumble. There would also be millions upon millions of environ mental refugees - people fleeing from the intruding sea, or equal ly from the deserts they have left in their wake after stripping the land of its vegetation. Those are the prospects and scientific advis ers to the UK government are warning that millions will die worldwide because of the processes of global warming that have already been unleashed.
The destabilising effect of planetary warming upon our climate systems is already being felt. Over the past decade, worldwide, we have seen virtually every climate record broken since reliable record-taking began a century ago. There has been a marked increase in the frequency and intensity of droughts, heat-waves,
The Ecologist, Vol. 29, No 2, March/April 1999 WE'R E CHANGIN G OUR CLIMATE ! WH O CA N DOUB T IT ?
forest fires, flash-floods, tornadoes, hurricanes and tropical storms, all of which have killed people, destroyed property and crops and left many millions homeless and destitute across the world in what seems a never-ending and worsening catalogue of disaster (see Climate Chaos map on the next page). Even the increase in severe winter weather events is consistent with and indeed the likely product of an overall global pattern of warming.
The correlations between warming and climate catastrophe are clear. In north-west Canada and Alaska mean annual temperatures a metre below the surface have risen a full degree Centigrade since 1989. There, as in Siberia, this is causing the permafrost to melt, releasing its store of methane, which is adding to the ever-grow ing increment of greenhouse gases. We are now seeing plants, insects, birds and mammals - and diseases - migrating northwards into regions too cold for them before, with all that means for the spread of disease and decimation of crops. In low-lying islands in the South Pacific farmers are having to abandon their fields because of sea-level rise and some islands have had to be vacated.
Average Temperature at the Earth's Surface
(1998 is d
®n 8 monthsh
Source: Goddard Institute for Space Studies
No group could be more pragmatic about disasters than the insurance companies and their con sortia. They are in no doubt that cli mate is changing disastrously: they see it in their rapidly escalating pay outs for those who are fortunate enough to be insured. As Paul Kovacs, an analyst with the Insur ance Board of Canada, remarks, "Every five years or so the costs of weather-related disasters have dou bled, with the last three years the costliest in history for the Canadian insurance industry." According to him, Canadian insurers will pay out $1.5 billion in weather-related claims by the end of 1998. That's in addition to $1.2 billion in direct assistance from federal and provincial govern ments. Globally, damage from extreme weather events simply in the first ten months of 1998 surpassed the total of all such losses during the entire decade of the 1980s.
Carbon Emissions from Fossil Fuel Burning
By Country Grouping, 1950 - 97
Sources: ORNL, BP
1955 1960 1965 1970 1975 1980 1985 1990 1995
improved correlations. Just a decade ago, the General Circulation Models (GCMs), as they were then, indicated that the global average surface tem perature should have risen by one degree Centigrade. The global warm ing sceptics were quick to point out that by the climatologists' own admission the actual overall temper ature increase was little more than half a degree. That gave the sceptics considerable ammunition for derid ing the efforts of the IPCC's scientif ic committee. And to add fuel to their cause, the lower atmosphere, about 3.5 kilometres up in the troposphere was found from satellite measure ments to have cooled by 0.05°C. "The theories were flawed," pro nounced the sceptics. Instead of a
'warming', the Earth was in the throes of a cooling, and who would
The Munich Reinsurance Corporation - one of the world's largest underwriters - estimates that the bill worldwide for severe weather over the past three years has topped $ 180 billion. Over the past ten years, claims Munich Re, the cost of all natural catastro phes, many relating to climate, has mounted 85 times above the cost for the 1960s, adjusted to present values.5
Flawed scienc e of th e climat e change sceptic s Despite the evidence of their eyes and of the growing body of sci ence, a very small number of self-created experts, set up to repre sent the powerful interests of the fossil fuel lobby in the United States and the oil-rich nations of the Middle East (see 'Corporate Hijacking of the Greenhouse Debate', pi 19), continue to lecture the world that current global warming either has nothing whatso ever to do with human activities, or that it is simply not happen ing. As laughable as such fly-by-night pundits may be, their influence over governments and in particular the entrenched Republican majority in the US Congress is particularly dangerous in preventing vital, immediate action to stem the ever-growing carbon emissions into the atmosphere.
One of the most vociferous of the band of climate change scep tics - Patrick Michaels, professor of climatology at the University of Virginia - has travelled the world to pooh-pooh the idea of global warming. But even he has been put on the defensive as the science gets more sophisticated and the models show vastly
want that! By drawing attention to the apparent cooling some kilo metres up they ignored the obvious discrepancy that average sur face temperatures were increasing by 0.13°C per decade and that the lower stratosphere was cooling by as much as 0.5°C per decade - both facts evidence for a significant surface warming.
That troublesome discrepancy has now been resolved. Frank Wentz of Remote Sensing Systems in Santa Rosa, California points out that the data being beamed down from satellites had been interpreted as i f the satellites were in a stationary, unchang ing orbit. No-one, he remarks, took account of the slippage over time of the satellites as they were inexorably pulled in closer to the Earth because of atmospheric friction. The slippage of 1.2 kilo metres every year gradually alters the angle at which the measure ments are made, therefore giving a spurious result. Wentz re-did the calculations to account for the real angle and discovered a warming trend of 0.07°C per decade - just what would be expect ed from the readings from other strata in the atmosphere.6
To add weight to the evidence that surface warming is occur ring, scientists from the British Antarctic Survey - that same body of scientists who were responsible for the discovery of the ozone hole in the mid-1980s - have discovered that the outer atmosphere is shrinking at the rate of one kilometre every five years, because, with more heat trapped at the surface, less is getting out to the outer atmosphere, which in fact is getting colder.7
Global warming critics, such as Fred Singer, President of the US Science and Environmental Policy Project were quite right to
The Ecologist, Vol. 29, No 2, March/April 1999