Climate Institute Inaugural Lecture

Friday 18 June 2004

By Crispin Tickell

My theme today is responses to climate change. We had a most interesting seminar on the subject at Green College Oxford on 27 April in which your distinguished President participated. But before going over the specific points which arose, I thought a few words of background would be useful.

Climate is a condition of life; and life is perhaps the most amazing thing about the universe and our tiny world within it. E.O. Wilson once wrote of a hypothetical journey outwards from the centre of the Earth.

“For the first twelve weeks you travel through furnace-hot rock and magma devoid of life. Three minutes to the surface, five hundred meters to go, you encounter the first organisms, bacteria feeding on nutrients that have filtered into the deep water-bearing strata. You breach the surface and for ten seconds glimpse a dazzling burst of life, tens of thousands of species of micro-organisms, plants and animals within a horizontal line of sight. Half a minute later almost all are gone. Two hours later only the faintest traces remain consisting largely of people in airliners who are filled in turn with bacteria.”

I begin in this way to underline the atmosphere around us in ever turbulent instability, yet with stability of its own. Neither climate nor life will continue indefinitely. Eventually our Sun will become a red giant, and expand to near the orbit of the Earth. Long before then life on Earth will be extinct.

It is notoriously difficult to distinguish natural from human-made changes in climate, and to determine if and when human activity became decisive on more than a local scale. As you all know there have been many natural changes over the last 1,000 years. Warming in the early Middle Ages allowed farming in Greenland and wine-growing in southern England. There were droughts in Western Europe in the 13^th century; increasing cold, leading to economic recession linked to the Black Death, in the 14^th century; ice fairs on the River Thames in the 17^th century; and warming in the northern hemisphere from around 1880, rising steeply from the 1970s onwards.

Successive reports from the Intergovernmental Panel on Climate Change, which brings together the vast majority of the world’s experts on the subject, show that the human contribution to climate change is now having a significant if not decisive effect.  Indeed in its most recent guidance to policy makers in 2001, the scientific working group of the Intergovernmental Panel concluded that “… in the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the [human-induced] increase in greenhouse gas concentrations”. Many other reports, organizations and conferences have echoed the same theme. I am thinking particularly of the UN Development Programme and the Ruschlikon Executive Round Table.

How warm would a warmer world be? According to the same group, “the globally averaged surface temperature is projected to increase by 1.4⁰C to 5.8⁰C over the period 1990 to 2100." This is a considerable increase on the 1.0⁰C to 3.5⁰C rise suggested in its previous report of November 1995. It covers a wide range of local variations. But overall “the projected rate of warming is much larger than the observed changes during the 20^th century, and is very likely to be without precedent during at least the last ten thousand years …"

Uncertainties remain. What is certain is that average world surface temperature is rising; six of the hottest years of the 20^th century occurred during the last decade. Although confidence in the modelling has increased, there remain many uncertainties which make it difficult to quantify the risks involved, or the regions most likely to be affected.

What would a warmer world look like? Here the uncertainties, region by region, multiply. Efforts have been made by the Intergovernmental Panel to assess possible impacts by continent, but the results are inevitably sketchy.  However interpreted, they suggest a different world and a correspondingly different distribution of human activity as people and other living organisms  adapt to change. Such change includes new patterns of rainfall and drought, more extreme events, and rising sea levels. For many it could be, as was well said, a genuine weapon of mass destruction.

First there are impacts on vegetation. We are already seeing tropical forest die back in northern Brazil, thereby adding to the deforestation in Amazonia caused by human agency. Recent reports suggest an area the size of Wales was deforested last year alone. There could be repercussive effects on hydrology throughout the Amazon basis eventually reaching as far north as Arizona. The transformation of tropical grasslands to desert or temperate grassland is increasing in Africa.

Next there are impacts on water resources, and in particular increased stresses in countries, particularly in Africa, subject to annual variations in rainfall.

Food supply is obviously affected. There may be increased crop yields in high and mid-latitude countries, but decreased yields in lower latitudes. In Africa there could be many more people at risk of hunger due to climate change alone by the 2050s. Already Africa is dependent on food imports to feed itself, and becoming more so.

Other impacts of climate change will be on coastal communities. Global sea level rise is a major hazard with incalculable consequences. It is also poorly understood. Recent work on the Arctic and Antarctic polar ice sheets shows that if temperature increases by more than about 3⁰C, cumulative melting could take place, and sea levels world wide could rise by many metres. At present the Intergovernmental Panel forecast is a rise of between 19 to 88 centimetres by 2100. Anything like the higher figure would put tens of millions of people at risk.

Human health will be affected. Micro-organisms respond rapidly to changes in temperature and moisture. Humans take 20 years to reproduce. Bacteria do the job in 20 minutes. Old diseases such as malaria could return and new diseases could arise, and have already done so. Health effects on the plants and animals on which we depend are beyond calculation.

Then there are the two jokers in the pack. There is the possibility of weakening of the Atlantic conveyor, which could bring renewed glaciation to Western Europe and eventually elsewhere as during the Younger Dryas 12,000 years ago. On the other hand there is the possibility of a runaway greenhouse effect, as at earlier times in the Earth’s history, such as possibly at the Permian/Triassic boundary 250 million years ago, and at the Palaeocene/Eocene boundary 55 million years ago. In each case vast releases of methane may have been the cause.

No one knows where the tipping points – the thresholds between one climate regime and another – may be. All that it is certain is that climate can change rapidly and even violently, and has done so many times in the past.

In Britain the Government has made more detailed predictions under its Climate Impacts Programme. It has recently produced its second set of scenarios of future impacts here. First our climate is likely to become warmer. By the 2080s the average annual temperature may rise by between 2⁰C and 3.5⁰C. There will be greater warming in the south and east rather than in the north and west, and there may be greater warming in summer and autumn than in winter and spring. High summer temperatures will become more frequent, whilst very cold winters will become more rare. A very hot August, such as experienced in l995 when temperatures over England and Wales averaged 3.4⁰C above normal, may occur one year in five by the 2050s and as often as three years in five by the 2080s. We had a painfully hot August last year. At the same time winters are likely to become wetter and summers drier throughout Britain. In the south and east summer precipitation may decrease by 50% or more by the 2080s and winter precipitation may increase by up to 30%.

Round our shores sea level will continue to rise. This may be the most serious change of all. The problem is confounded by another factor: that of isostatic change. Since the last ice age much of southern and eastern Britain has been sinking, and northern and western Britain have been rising in relation to sea level. The map of British coastlines will look very different by the 2080s.

A good illustration of human vulnerability to climatic change world wide lies in the effects of the Nino (otherwise known as the El Nino Southern Oscillation or ENSO), or its opposite the Nina. Relatively small changes can have gigantic effects.

As most people now know, the Nino signifies the arrival every four to six years or so of warm water from the western Pacific which overlies an upwelling current of cool water from the south. It thereby changes weather conditions, first within the region and then in different degrees in other parts of the world. Around a quarter of the Earth’s surface is affected by it one way or another.

During a Nino year there are severe droughts in the countries bordering the western Pacific: Indonesia, New Guinea, north-east Australia and the Philippines, with weakened summer monsoon rainfall over southern Asia generally, including India. In the countries bordering the eastern Pacific it is the reverse: there is heavy rainfall in northern Peru, Ecuador and Chile with drier spots in southern Peru and Bolivia.

Further away concurrent changes have been observed. For example north-east South America and southern Africa are drier, and east Africa and the southern United States are wetter. There tend to be fewer Atlantic hurricanes: the reason is that westerly winds in the upper atmosphere blow the tops off hurricane formations before they have time to gather strength.   In Nina years it is the opposite with more Atlantic but fewer Pacific hurricanes (otherwise known as typhoons).

Such perturbations obviously affect the conditions of life in all its aspects. For some organisms – from plants and insects to fish and mammals – it is a disaster, with sharp falls in population density; for others it is an opportunity to be exploited while it lasts; but for most it must be an experience which they are broadly adapted to cope with, or at least to recover from.

Micro-organisms deserve a special word. Floods bring opportunities for the vectors of such diseases as malaria, dengue and yellow fever, encephalitis and schistosomiasis, and for the agents of such diseases as hepatitis, dysentery, typhoid and cholera. Recent research has suggested mechanisms for the spread of cholera in South America during Nino events. Warm or brackish water combines with run off from the land to produce local plankton blooms in which the cholera bacillus flourishes. Another example is the apparent relationship between the Nino and epidemics of African horse sickness. No doubt there are comparable stories to tell about other parts of the world.

Not surprisingly the scale of the changes symbolized by the Nino, with prospects of more to come, has brought together the world’s scientific community in unprecedented fashion. Let me refer you to a Declaration made by over a thousand scientists from the four great global research programmes at Amsterdam in July 2001. There it states squarely that

• "Human activities have the potential to switch the Earth’s System to alternative modes of operation that may prove irreversible and less hospitable to humans and other life … the Earth’s System has moved well outside the range of the natural variability exhibited over the last half million years at least … the Earth is currently operating in a no-analogue state.”
  
• “The accelerating human transformation of the Earth’s environment is not sustainable.   Therefore the business-as-usual way of dealing with the Earth’s System is not an option. It has to be replaced – as soon as possible – by deliberate strategies of management that sustain the Earth’s environment while meeting social and economic development objectives.”

The same themes have been taken up by others since then. On 14 November last year Science ran a series of articles on our planetary prospects, underlining the effects of damage to the global ecosystem. On 5 January the British Government’s Chief Scientific Adviser wrote a forthright article, also in Science, when he said that delay in tackling the specific issue of climate change “for decades, or even just years” was not a serious option”, and it represented “the most severe problem we are facing today – more serious even than the threat of terrorism”.  

This is strong stuff. It conforms with the depressing conclusion in the Global Environmental Outlook 2000 report of the UN Environment Programme that almost all environmental problems are getting worse and in many cases the long-term effects have yet to be seen. An additional factor is the widening gap between the world’s rich and poor people, and the disproportionate consumption of the Earth’s resources.

So what on Earth – a familiar phrase – are we going to do next? The problems are so intimidating that most people, including politicians and leaders of all kinds, simply do not want to confront them, or feel capable of doing so. The bridge between science and politics is always long and rickety. 

There have been many conferences, some international agreements like those on climate change and protection of biological diversity, and three world summits (Stockholm 1972, Rio de Janeiro 1992, and Johannesburg 2002). But even if some governments have begun to take action on some of the issues, for example energy and transport policy, most have continued to ride a tide which carries them ever further in the wrong direction. The biggest villain is the biggest polluter. I am sorry to have to say so but the Bush Administration seems determined to pretend that the problems are unproven, and to ignore the advice of its own as well as of the world’s scientists. The positions of individual US states, and of certain corporations are of course different. They should have all the encouragement they can get.

Even those who accept the premise of the need for change have very different priorities. It is easy to bleat about the problems but more difficult to set priorities for action. My own are as follows:

• We need urgent action on climate change. This means urgent action on energy policy. So much has been said on this that I will not repeat it. Let me say simply that I do not think that technical wheezes – mirrors in space, windmill extractors, iron sprays in the oceans, cloud whitening and the rest – could ever do the trick, and would probably create more problems than they solved.
• We need to do far more to educate public opinion. Here some initiatives are pending with support from industries and businesses likely to be affected: BP, Swiss Re and others.
• We need to look again at economics and the way we measure wealth, welfare and the human condition in terms of the Earth’s good health. Neither state-directed economics nor market economics can alone supply the right framework. As has been well said, the economy is a wholly owned subsidiary of the environment.
• We need to apply the principles of common but differentiated responsibility, accepting that industrial countries have much bigger responsibilities for what has gone wrong as well as what has gone right, and should give the example in their domestic policies.
• We need to focus on the needs and attitudes of coming generations:  in short give new direction to the educational process. This process in industrial, as in any other kind of country, is rightly called capacity building.

All involve the ability to accept accelerating change, learn to think, and ultimately to behave differently. We need leadership from above, and pressure from below; and – dare I say it? – one or two benign catastrophes, not too big and not too small, not too quick and not too slow. So far there have been few catastrophes with sufficient impact. No-one likes the spread of African bees, the world-wide decline in amphibians, the mass deaths of trees, the eruption of such new diseases as AIDS and of lethal bacteria resistant to antibiotics. The miners’ canaries may be dying all over the place but we do not always know why. It is often difficult to link cause with effect. Nor do we want a hit from space or internal social collapse.

But the price of sticking to our present system of values and not adapting to new ones is intolerably high. So far all past urban civilizations – some 30 of them – have crashed. None over time learned how to reach a well-regulated steady state with population in balance with natural resources. There is no reason to believe that ours is any different. Indeed current signs are to the contrary.

We continue to talk about conquering Nature as if we were not a small but immodest part of it. I end as I began with sheer wonder at the miracle of life, and the sense of human littleness within the tissue of living things. The mediaeval abbess Hildegard of Bingen once wrote:

                        “…I ignite the beauty of the plains,
                        I sparkle the waters,
                        I burn in the sun and the moon and the stars…
                        I adorn all the earth,
                        I am the breeze that nurtures all things great…
                        I am the rain coming from the dew
                        That causes the grasses to laugh with the joy of life.”

I think that in all of us there is a most precious impulse: to laugh with the joy of life. The day we no longer do so we are lost indeed.

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