THE BREAKDOWN OF CLIMATE

HUMAN CHOICES OR GLOBAL DISASTER?

PETER BUNYARD

FLORIS BOOKS            1999

PART I

Introduction

The modern world

• Today we live in a man-made world that we isolate as far as possible from the elements. Ironically, our attempts to control our immediate environment have exacerbated the very problem we are trying to avoid – global warming.
• However much we try to generate our own climate, the reality is that our very survival depends on our relationship with the natural climate.
• What we grow in our fields, how and when we harvest, what water resources we have, whether we are likely to suffer drought or flood, how cold or warm the winters are, these issues are all intimately linked to climate.
• In addition, the world population is increasing rapidly, especially since World War II, and a growing population needs a reliable food base to sustain it, which requires climate to remain within reasonable limits for animals and crop husbandry.

The past

• We know from history that the idea of a stable, unchanging climate is illusory. The climate has changed dramatically even over the past thousand years.

The present: 1990-95

• Worldwide, the past decade has witnessed the warmest average temperatures for a century. 1990 broke one record after another. 1991 might have followed suit if it had not been for the massive eruption of Mount Pinatubo which created aerosols high in the atmosphere that reflected light back into space, and so cooled the Earth.
• In 1993, the Mississippi River burst its banks and inundated vast areas of land following the worst rains for 500 years.
• By 1994, the aerosols from Mount Pinatubo had been washed out of the atmosphere and global temperatures began to rise. In northern Europe in 1995, the hottest summer since records began in the early 18^th century, was contrasted by some of the most extensive winter floods for a hundred years.
• 1995 was portrayed as ‘The Year of the Hurricane’ as by early October sixteen tropical storms, all with wind speeds above 120 kph left a swathe of destruction in their wake. Hurricane Opal attained wind speeds of 240 kph, killing seventeen people and leaving damage amounting to $2 billion in the United States alone.

El Niňo

• Most years the trade winds blow across the Pacific Ocean from east to west, driving the surface waters with them, which end up in the seas of South-East Asia creating the monsoons.
• In 1997 the trade winds weakened and failed. The surface waters of the tropical Pacific changed direction and began collecting along the flank of South America.
• The high pressure zone – bright weather and clear skies – centred itself over South-East Asia, while the low pressure zone – usually associated with monsoon rains – shifted to the deserts along the coast of Peru, which is where the rain fell, thousands of miles away from its usual destination.
• As Peruvian fishermen know, the switch in the Pacific currents, and the strengthening or weakening of the trade winds, is a natural phenomenon which takes place every few years.
• Anchovies thrive in cool nutrient-rich waters brought by the Humboldt current that flows along the coast from Antarctica. When the Pacific currents change direction, the Humboldt current is held at bay, replaced by the warm, nutrient-poor tropical waters that sweep in from the western pacific. As far as the fishermen of Peru are concerned, their catch virtually vanishes.
• The fishermen dubbed the warm water current El Niňo – The Christ Child – because it manifested itself in the days around Christmas.

Climate change

• El Niňo used to appear every few years, at most twice every decade. Over the past two decades it has even appeared several times in a row and its effects have become more pronounced.
• Sudden switches in climate have always been potentially disastrous for human populations; northern Europe suffered devastating famine in the late Middle Ages when the warm climate of the previous centuries vanished abruptly.
• Never have we been so close to the limits in terms of the amount of land used and the availability of fundamental resources such as water.
• Man, with his crops and livestock, has now taken over the management of 40% of the total land surface’s capacity for production. As the world’s population is expected to double by the middle of the next century, and unless we double food production from currently available land, it will mean that we have to manage 80% of the total land surface, involving intensive production in marginal places such as high mountains, and swamps.
• Climate change could put paid to any plans we have for finding the resources to feed the population in the future. Yet the climate is changing.
• In 1990 scientists reported that more than a century of industrial activities could be responsible for the 0.5ºC average rise in the surface temperature of the planet.
• 1998 was the worst to date for climatic disasters, with worldwide estimates of damage amounting to more than $50 billion. Over the past ten years the cost of all natural catastrophes, many relating to climate, has risen 85 times above the cost for the 1960s.

Causes of climate change

• The Earth’s surface is kept warm because of greenhouse gases which let light through but retain heat. From physics we know that without greenhouse gases  the average surface temperature of our planet would be -18ºC.
• The total amounts of carbon dioxide we have added to the atmosphere are staggering: 190 billion tones over the past fifty years. In that period we have emitted three times the carbon dioxide released by mankind over the rest of time put together.
• Approximately half the carbon dioxide is absorbed into the oceans, soils and perhaps even buried in sediments. Scientists assigned to the IPCC (International Panel on Climate Change) confirmed that if we continue to pour our waste gases into the atmosphere, we could expect temperatures to soar over the coming century.
• No one can predict absolutely what might happen, but we could experience dramatic changes to local climate, with severe consequences for property, lifestyle and essential food production, let alone for wildlife.

The case against global warming

• A small number of self-created experts, who represent the powerful interests of the fossil fuel lobby in the United States and the oil-rich nations of the Middle East, continue to lecture the world that current global warming either has nothing whatsoever to do with human activities, or is simply not happening.

The future

• Viable agriculture needs a stable climate. If we cannot anticipate from one year to the next what and when to sow and what sort of harvest to expect because the climate is going through unpredictable convulsions, then we are in serious trouble.
• We are told that the worst impact on agriculture will be in Africa, the Middle East and the Indian subcontinent. Most of Europe and the humid tropical countries of South-Eat Asia will benefit from global warming, at least until the 2080s (see Chapter 11).
• With only 4% of the world’s population, the United States is responsible for nearly one quarter of the world’s greenhouse gas emissions, and its citizens emit five times more greenhouse gases on average than anyone else in the world.
• In 1992, the US administration voluntarily agreed that by 2000 it would cut its greenhouse gas emissions to 1990 levels. Today, those emissions stand at 13% higher than 1990 levels and in a decade, based on current projections, are likely to be 30% higher.
• Even if industrialized countries achieve reductions over the next 10 years, developing countries are rapidly increasing their greenhouse gas emissions. Currently, greenhouse gas emissions are increasing at rates even faster than the more extreme of the IPCC’s business-as-usual scenarios (see Appendix I).
• Unless drastic action is taken now carbon dioxide levels in the atmosphere will double every 27 years. This is a very different scenario from a doubling of carbon dioxide by 2080, on which most policy makers are basing their understanding of what the future holds in store.

The consequences

• With current trends, instead of the maximum 4.5ºC average rise in temperature by 2100, indicated by the IPCC for a business-as-usual projection, average temperatures could rise by 10ºC or even 14ºC. The consequences in terms of climatic disruption would be enormous.
• Those most at risk from global warming are countries with considerable areas of low-lying land, such as many islands in the Pacific, Caribbean and Indian Oceans, or regions with large delta areas, such as Bangladesh (see Chapter 6).
• Global warming has its paradoxical side, perhaps the most bizarre being the likelihood that the Gulf Stream will stall as an excess of freshwater flowing into the North Atlantic and an increase in melting sea ice cause the density of surface waters to fall, so that they no longer sink. (see Chapter 6).

Gaia

• In the late 1960s the British scientist, James Lovelock, came up with a thesis, which he later called Gaia, purporting that life and the atmosphere were bound together is a self-regulating system.
• Scientists have increasingly discovered the influence of life in many Earth processes, including the formation of continents and possibly tectonic movements of the crustal plates.
• The Gaia thesis suggest that life is not a mere passenger on this planet but is indissolubly connected to the processes of transformation that take place all over the earth’s surface.
• It is becoming increasingly apparent that life itself maintains suitable conditions for life, and conversely, a planet that is replete with healthy living systems has an adequate and well-regulated climate.
• What if life, as a whole, can no longer cope with the changing conditions brought about through global warming? What if life no longer removes carbon dioxide from the atmosphere at the rate that is built into the climate models?
• Perhaps our ancestors did get it right. At least they believed in their effect on the cosmos, hence on the ‘order of things’; that it was in their hands to restore equilibrium by returning to some form of natural, accepted behaviour. Are we too late to redress the balance?

Chapter 1: The Nature and History of Climate

• Summer occurs because the Earth faces the sun for much more of the day than in winter. Such differences reach their extremes at the poles, which in mid-summer barely see darkness or light in mid-winter.
• Close to the Equator the length of the day remains almost constant. In fact, the Equator receives nearly two and a half times more sunlight during the course of the year than the poles.
• Weather shows considerable variation from day to day, let alone from year to year. Climatologists agree that the minimum period for finding the essence of climate is about 30 years and use a 30-year period to give a reference temperature with which their models must accord, before they can experiment with factors such as increasing greenhouse gas levels.
• However, even that time span may not be enough to cover the entire range of natural fluctuations that accompany climate.
• At times we can pinpoint the likely cause of short term climatic variation. A volcanic eruption like that in June 1991 of Mount Pinatubo in the Philippines, can send sun-reflecting particles and aerosols into the upper atmosphere, causing cooler summers for a year or more.
• Even more dramatic was the eruption in 1815 of Tamboro in the East Indies which blew such a thick veil of volcanic debris into the sky that the sun barely shone for weeks.

Climate and weather

• If climate reveals regular features that can be depended upon from one year to the next, the weather, by contrast, may seem irregular and even chaotic.
• The temperature shift, within a few hours, may be far greater than the average change in temperature that one would expect from the transition from an ice age to a warm interglacial period.

Climate and land

• For much of the several million years of human existence on the planet, men survived as hunter-gatherers following the movements of animals which chased the seasons.
• It was probably in pursuit of game that humans first crossed the Bering Straits into the North American continent some tens of thousands of years ago.
• Evidence suggests that horticulture and the domestication of animals took place only after the last ice age had come to an end.
• Farming made long term settlements possible but there was a double-edge to the weather. On the one hand, settlement enabled the storage of surplus produce, so that winters could be faced without having to move away.
• On the other hand, poor weather during the growing or harvesting season, could lead to disastrous famines and the collapse of civilizations.

Climate and our past

• Some 40 years ago, the Israeli botanist, Michael Evenari, discovered how the Nabateans managed to grow crops in the Negev desert in the centuries before Christ. Channels formed a system to collect the run-off from flash floods, and a mere few millimeters of rainfall would provide sufficient water for crops that could sustain surrounding settlements.
• Using Nabatean techniques, Michael Evenari has transformed parts of the desert into productive horticultural plots that now sustain almonds, wheat, barley and a host of other crops.
• Prehistoric cave paintings offer a glimpse of what the climate may have been like as long as 40,000 years ago. We have evidence from fossilized seeds and vegetation that the climate over much of the planet was much drier than today.
• The ice, sometimes more than 30m thick, forced the land mass down; nevertheless, the sea level was still about 100 metres lower than it is today.

Better times

• One way we know that climate has shifted is by what we can grow. The climate improved in what has been called the Medieval Optimum which lasted from 900 to 1250, and which was probably, on average, one degree Centigrade warmer than today.
• Wine production flourished in the south of England. Those times saw the construction of magnificent medieval cathedrals all over Europe. The good harvests of the time and overall prosperity meant that high culture could be afforded.