Monthly Archives: June 2011
by Stan Hirst
Just one month ago the federal general elections in Canada put the Conservative Party firmly in power. Responses to the election outcome amongst environmental groups and environmentally-concerned individuals across the country ranged from disappointment to dismay to a number of other reactions, most of them negative.
The reason is not hard to discern. Conservatives in Canada are perceived as having an awful environmental track record. For the recent election, the Conservative Party‘s election platform contained not one word about environment. By contrast, the opposition Liberal Party promised to create clean energy jobs, invest in clean energy and energy efficiency, create a cap-and-trade system for reductions in greenhouse gas emissions, and to protect Canada’s air, oceans, waterways, forests and Arctic resources. The New Democratic Party’s platform proposed a shift away from fossil-fuel dependence, underlined the compatibility of environmental health and economic growth, and promised to develop green energy industries.
The future doesn’t seem to bode much better. The background documents for the June 2011 Conservative National Convention, at which future policy was set, contained just one short statement on an environmental topic, i.e. “we believe that an effective international emissions reduction regime on climate change must be truly global and must include binding targets for all the world’s major emitters, including China and the United States”.
Is this disconnect between conservatism and environmental consciousness in Canada typical of all conservatives or conservative governments? Consider the following statements from south of the 49th parallel.
- I do not intend that our natural resources should be exploited by the few against the interests of the many.
- The only trouble with capitalism is capitalists – they are too damn greedy.
- As we peer into society’s future, we – you and I, and our government – must avoid the impulse to live only for today, plundering for, for our own ease and convenience, the precious resources of tomorrow. We cannot mortgage the material assets of our grandchildren without risking the loss also of their political and spiritual heritage.
- The basic causes of our environmental troubles are complex and deeply embedded. They include: our past tendency to emphasize quantitative growth at the expense of qualitative growth; the failure of our economy to provide full accounting for the social costs of environmental pollution; the failure to take environmental factors into account as a normal and necessary part of our planning and decision making; the inadequacy of our institutions for dealing with problems that cut across traditional political boundaries; our dependence on conveniences, without regard for their impact on the environment; and more fundamentally, our failure to perceive the environment as a totality and to understand and to recognize the fundamental interdependence of all its parts, including man himself.
- We are now facing hard choices in our energy policy. Future generations — my children and grandchildren, along with yours — will have to live with the decisions we make today. And so it is time for us to make some tough and — hopefully — smart choices regarding our energy use and production before it is too late.
All penned and uttered by democrats and green-tinged radicals, right? Wrong. All spoken by hard-core Republican conservatives – Theodore Roosevelt, Herbert Hoover, Dwight Eisenhower, Richard Nixon and John McCain.
Or maybe the disconnect between conservatism and environmental consciousness in Canada now typifies the attitudes of mainstem right-wing parties struggling to deal with 21st century environments? A quick check around the globe suggests that this isn’t true either.
The British Tories, the party of Disraeli, Churchill and Thatcher, are today in a coalition with the Liberal Democrats. The Conservative 2011 programme declares that Britain needs to protect the environment for future generations, make the economy more environmentally sustainable, and that much more needs to be done to support the farming industry, protect biodiversity and encourage sustainable food production.
The governing German party, the Christian Democratic Union, declares in its manifesto that its policies are based on the Christian view of Man and his responsibility before God, and then goes on to state that the objective of an ecological and social market economy, as they see it, is to achieve a synthesis of economy, social justice and ecology. Amongst a host of economic and policy actions cited as a basis for this synthesis, the CDU include the need for ecological elements in tax legislation, environmental levies, compensation schemes, certification and liability regulations, and the cutting edge concept, at least by current Canadian standards, of rewarding environmentally sensitive actions by using market incentives and linking costs to environmental damage to establish ecologically realistic prices.
Flipping to the other side of the globe, we find the most conservative party in Australia, the rural-based National Party of Australia, outlining its 2011 environmental platform by supporting targets for greenhouse gas emissions, proposing direct action plans to reduce emissions through soil carbon sequestration and use of bio-char, revegetation of marginal land, clean coal technology, carbon capture and the use of algae, and encouraging public participation in voluntary carbon markets involving individuals, communities, agriculture and business, and strong state support to non-petroleum based fuels. Pretty radical stuff all around.
So why are Canadian conservatives not up there with the rest of the conservative world in addressing urgent environmental issues?
Conservatives believe in personal responsibility, limited government, free markets, individual liberty, traditional values and a strong national defence. Thus, conservative policies generally emphasize empowerment of the individual to solve problems. By contrast, those of more liberal persuasion believe in government action to achieve equal opportunity, equality for all, alleviation of social ills and the protection of civil liberties and individual and human rights. So liberal policies generally emphasize the need for the government to solve problems.
Looking at energy through this type of filter, we might see that Canadian conservatives consider fossil fuels to be good sources of energy (which they are of course in Canada) and, since they are abundant, their exploitation should be promoted and increased both on land and at sea. Increased domestic production by large corporations would lead to lower domestic prices plus huge incomes from the two biggest gulpers of energy on the planet – the U.S. to our south and the ever-burgeoning Chinese economy just across the Pacific. Canadian conservatives might feel that wind, solar and biomass will never provide comparable levels of plentiful, affordable and, above all, profitable sources of power. The opposing liberal view points, i.e. that oil is a diminishing resource, that other sources of energy must be explored, that government must produce a national plan for all energy resources, and must subsidize alternative energy research and production don’t play well in Canada because fossil fuels generally are not diminishing resources. They may be getting more difficult and expensive to recover, but that is just part of the ongoing and traditional challenge for private enterprise.
Looking at climate change through the same filter would surely lead a market-conscious conservative to conclude that since global warming is caused primarily by an increased production of carbon dioxide through the burning of fossil fuels, which Canada produces, and burns, in prolific quantities, the combating of climate change needs to involve realistic pricing of fossil fuel extraction and use through carbon taxation and firm regulation, through reduction in fossil fuel use by a plethora of measures to increase energy supply from renewable sources, and by a shift in consciousness towards regarding earth as an ecosystem, and not as a supply depot. All of this is missing from the current conservative platform, who sees it all as just raising taxes, increasing prices, losing jobs and impacting on individual freedoms. A prevalent conservative approach to dealing with climate change is to deny that it is happening at all.
Climate change presents a very difficult problem for Canadian conservatives. The root cause of the problem is burgeoning greenhouse gas emissions from fossil fuel use around the globe. Once upon a time the major contributors of greenhouse gases to the global climate were North America and western Europe. Now they’re increasingly being put out by the Asian industrial powers, and Canada contributes to their impacts by selling them oil and coal. And while the causes of climate change are global, the impacts – storms, droughts, rising sea levels, disappearing glaciers, changing weather patterns – will be felt globally as well. The items in the classic conservative toolkit – personal responsibility, limited government, free markets, individual liberty, traditional values and empowerment of the individual to solve problems – have not thus far dealt well with the root causes of climate change. Maybe they’ll deal better with the consequences.
Climate change is a defining issue for our time. The geological record contains abundant evidence of the ways in which Earth’s climate has changed in the past. That evidence is highly relevant to understanding how it may change in the future. The Council of the Society is issuing this statement as part of the Society’s work “to promote all forms of education, awareness and understanding of the Earth and their practical applications for the benefit of the public globally”. The statement is intended for non-specialists and Fellows of the Society. It is based on analysis of geological evidence, and not on analysis of recent temperature or satellite data, or climate model projections. It contains references to support key statements, indicated by superscript numbers, and a reading list for those who wish to explore the subject further.
What is climate change, and how do geologists know about it?
The Earth’s temperature and weather patterns change naturally over time scales ranging from decades, to hundreds of thousands, to millions of years1. The climate is the statistical average of the weather taken over a long period, typically 30 years. It is never static, but subject to constant disturbances, sometimes minor in nature and effect, but at other times much larger. In some cases these changes are gradual and in others abrupt.
Evidence for climate change is preserved in a wide range of geological settings, including marine and lake sediments, ice sheets, fossil corals, stalagmites and fossil tree rings. Advances in field observation, laboratory techniques and numerical modelling allow geoscientists to show, with increasing confidence, how and why climate has changed in the past. For example, cores drilled through the ice sheets yield a record of polar temperatures and atmospheric composition ranging back to 120,000 years in Greenland and 800,000 years in Antarctica. Oceanic sediments preserve a record reaching back tens of millions of years, and older sedimentary rocks extend the record to hundreds of millions of years. This vital baseline of knowledge about the past provides the context for estimating likely changes in the future.
What are the grounds for concern?
The last century has seen a rapidly growing global population and much more intensive use of resources, leading to greatly increased emissions of gases, such as carbon dioxide and methane, from the burning of fossil fuels (oil, gas and coal), and from agriculture, cement production and deforestation. Evidence from the geological record is consistent with the physics that shows that adding large amounts of carbon dioxide to the atmosphere warms the world and may lead to: higher sea levels and flooding of low-lying coasts; greatly changed patterns of rainfall2; increased acidity of the oceans 3,4,5,6; and decreased oxygen levels in seawater7,8,9.
There is now widespread concern that the Earth’s climate will warm further, not only because of the lingering effects of the added carbon already in the system, but also because of further additions as human population continues to grow. Life on Earth has survived large climate changes in the past, but extinctions and major redistribution of species have been associated with many of them. When the human population was small and nomadic, a rise in sea level of a few metres would have had very little effect on Homo sapiens. With the current and growing global population, much of which is concentrated in coastal cities, such a rise in sea level would have a drastic effect on our complex society, especially if the climate were to change as suddenly as it has at times in the past. Equally, it seems likely that as warming continues some areas may experience less precipitation leading to drought. With both rising seas and increasing drought, pressure for human migration could result on a large scale.
When and how did today’s climate become established?
The Earth’s climate has been gradually cooling for most of the last 50 million years. At the beginning of that cooling (in the early Eocene), the global average temperature was about 6-7 ºC warmer than now10,11. About 34 million years ago, at the end of the Eocene, ice caps coalesced to form a continental ice sheet on Antarctica12,13. In the northern hemisphere, as global cooling continued, local ice caps and mountain glaciers gave way to large ice sheets around 2.6 million years ago14.
Over the past 2.6 million years (the Pleistocene and Holocene), the Earth’s climate has been on average cooler than today, and often much colder. That period is known as the ‘Ice Age’, a series of glacial episodes separated by short warm ‘interglacial’ periods that lasted between 10,000-30,000 years15,16. We are currently living through one of these interglacial periods. The present warm period (known as the Holocene) became established only 11,500 years ago, since when our climate has been relatively stable. Although we currently lack the large Northern Hemisphere ice sheets of the Pleistocene, there are of course still large ice sheets on Greenland and Antarctica1.
What drives climate change?
The Sun warms the Earth, heating the tropics most and the poles least. Seasons come and go as the Earth orbits the Sun on its tilted axis. Many factors, interacting on a variety of time scales, drive climate change by altering the amount of the Sun’s heat retained at the Earth’s surface and the distribution of that heat around the planet. Over millions of years the continents move, ocean basins open and close, and mountains rise and fall. All of these changes affect the circulation of the oceans and of the atmosphere. Major volcanic eruptions eject gas and dust high into the atmosphere, causing temporary cooling. Changes in the abundance in the atmosphere of gases such as water vapour, carbon dioxide and methane affect climate through the Greenhouse Effect – described below.
As well as the long-term cooling trend, evidence from ice and sediment cores reveal cycles of climate change tens of thousands to hundreds of thousands of years long. These can be related to small but predictable changes in the Earth’s orbit and in the tilt of the Earth’s axis. Those predictable changes set the pace for the glacial-interglacial cycles of the ice age of the past 2.6 million years17. In addition, the heat emitted by the Sun varies with time. Most notably, the 11-year sunspot cycle causes the Earth to warm very slightly when there are more sunspots and cool very slightly when there are few. Complex patterns of atmospheric and oceanic circulation cause the El Niño events and related climatic oscillations on the scale of a few years1,18.
What is the Greenhouse Effect?
The Greenhouse Effect arises because certain gases (the so-called greenhouse gases) in the atmosphere absorb the long wavelength infrared radiation emitted by the Earth’s surface and re-radiate it, so warming the atmosphere. This natural effect keeps our atmosphere some 30ºC warmer than it would be without those gases. Increasing the concentration of such gases will increase the effect (i.e. warm the atmosphere more)19.
What effect do natural cycles of climate change have on the planet?
Global sea level is very sensitive to changes in global temperatures. Ice sheets grow when the Earth cools and melt when it warms. Warming also heats the ocean, causing the water to expand and the sea level to rise. When ice sheets were at a maximum during the Pleistocene, world sea level fell to at least 120 m below where it stands today. Relatively small increases in global temperature in the past have led to sea level rises of several metres. During parts of the previous interglacial period, when polar temperatures reached 3-5°C above today’s20, global sea levels were higher than today’s by around 4-9m21. Global patterns of rainfall during glacial times were very different from today.
Has sudden climate change occurred before?
Yes. About 55 million years ago, at the end of the Paleocene, there was a sudden warming event in which temperatures rose by about 6ºC globally and by 10-20ºC at the poles22. Carbon isotopic data show that this warming event (called by some the Paleocene-Eocene Thermal Maximum, or PETM) was accompanied by a major release of 1500-2000 billion tonnes or more of carbon into the ocean and atmosphere. This injection of carbon may have come mainly from the breakdown of methane hydrates beneath the deep sea floor10, perhaps triggered by volcanic activity superimposed on an underlying gradual global warming trend that peaked some 50 million years ago in the early Eocene. CO2 levels were already high at the time, but the additional CO2 injected into the atmosphere and ocean made the ocean even warmer, less well oxygenated and more acidic, and was accompanied by the extinction of many species on the deep sea floor. Similar sudden warming events are known from the more distant past, for example at around 120 and 183 million years ago23,24. In all of these events it took the Earth’s climate around 100,000 years or more to recover, showing that a CO2 release of such magnitude may affect the Earth’s climate for that length of time25.
Are there more recent examples of rapid climate change?
Abrupt shifts in climate can occur over much shorter timescales. Greenland ice cores record that during the last glacial stage (100,000 – 11,500 years ago) the temperature there alternately warmed and cooled several times by more than 10ºC 26,27. This was accompanied by major climate change around the northern hemisphere, felt particularly strongly in the North Atlantic region. Each warm and cold episode took just a few decades to develop and lasted for a few hundred years. The climate system in those glacial times was clearly unstable and liable to switch rapidly with little warning between two contrasting states. These changes werealmost certainly caused by changes in the way the oceans transported heat between the hemispheres.
How did levels of CO2 in the atmosphere change during the ice age?
The atmosphere of the past 800,000 years can be sampled from air bubbles trapped in Antarctic ice cores. The concentrations of CO2 and other gases in these bubbles follow closely the pattern of rising and falling temperature between glacial and interglacial periods. For example CO2 levels varied from an average of 180 ppm (parts per million) in glacial maxima to around 280 ppm during interglacials. During warmings from glacial to interglacial, temperature and CO2 rose together for several thousand years, although the best estimate from the end of the last glacial is that the temperature probably started to rise a few centuries before the CO2 showed any reaction. Palaeoclimatologists think that initial warming driven by changes in the Earth’s orbit and axial tilt eventually caused CO2 to be released from the warming ocean and thus, via positive feedback, to reinforce the temperature rise already in train28. Additional positive feedback reinforcing the temperature rise would have come from increased water vapour evaporated from the warmer ocean, water being another greenhouse gas, along with a decrease in sea ice, and eventually in the size of the northern hemisphere ice sheets, resulting in less reflection of solar energy back into space.
How has carbon dioxide (CO2) in the atmosphere changed over the longer term?
Estimating past levels of CO2 in the atmosphere for periods older than those sampled by ice cores is difficult and is the subject of continuing research. Most estimates agree that there was a significant decrease of CO2 in the atmosphere from more than1000 ppm at 50 million years ago (during the Eocene) to the range recorded in the ice cores of the past 800,000 years22. This decrease in CO2 was probably one of the main causes of the cooling that led to the formation of the great ice sheets on Antarctica29. Changes in ocean circulation around Antarctica may also have also played a role in the timing and extent of formation of those ice sheets30,31,32.
How has carbon dioxide in the atmosphere changed in recent times?
Atmospheric CO2 is currently at a level of 390 ppm. It has increased by one third in the last 200 years33. One half of that increase has happened in the last 30 years. This level and rate of increase are unprecedented when compared with the range of CO2 in air bubbles locked in the ice cores (170-300 ppm). There is some evidence that the rate of increase in CO2 in the atmosphere during the abrupt global warming 183 million years ago (Early Jurassic), and perhaps also 55 million years ago (the PETM), was broadly similar to today’s rate34.
When was CO2 last at today’s level, and what was the world like then?
The most recent estimates35 suggest that at times between 5.2 and 2.6 million years ago (during the Pliocene), the carbon dioxide concentrations in the atmosphere reached between 330 and 400 ppm. During those periods, global temperatures were 2-3°C higher than now, and sea levels were higher than now by 10 – 25 metres, implying that global ice volume was much less than today36. There were large fluctuations in ice cover on Greenland and West Antarctica during the Pliocene, and during the warm intervals those areas were probably largely free of ice37,38,39. Some ice may also have been lost from parts of East Antarctica during the warm intervals40. Coniferous forests replaced tundra in the high latitudes of the Northern Hemisphere41, and the Arctic Ocean may have been seasonally free of sea-ice42.
When global temperature changed, did the same change in temperature happen everywhere?
No. During the glacial periods in the Pleistocene the drop in temperature was much greater in polar regions than in the tropics. There is good evidence that the difference between polar and tropical temperatures in the warmer climate of the Eocene to Pliocene was smaller than it is today. The ice core record also shows differences between Greenland and Antarctica in the size and details of the temperature history in the two places, reflecting slow oceanic heat transport between the two poles16.
In conclusion – what does the geological record tell us about the potential effect of continued emissions of CO2?
Over at least the last 200 million years the fossil and sedimentary record shows that the Earth has undergone many fluctuations in climate, from warmer than the present climate to much colder, on many different timescales. Several warming events can be associated with increases in the ‘greenhouse gas’ CO2. There is evidence for sudden major injections of carbon to the atmosphere occurring at 55, 120 and 183 million years ago, perhaps from the sudden breakdown of methane hydrates beneath the seabed. At those times the associated warming would have increased the evaporation of water vapour from the ocean, making CO2 the trigger rather than the sole agent for change. During the Ice Age of the past two and a half million years or so, periodic warming of the Earth through changes in its position in relation to the sun also heated the oceans, releasing both CO2 and water vapour, which amplified the ongoing warming into warm interglacial periods. That process was magnified by the melting of sea ice and land ice, darkening the Earth’s surface and reducing the reflection of the Sun’s energy back into space.
While these past climatic changes can be related to geological events, it is not possible to relate the Earth’s warming since 1970 to anything recognisable as having a geological cause (such as volcanic activity, continental displacement, or changes in the energy received from the sun)43. This recent warming is accompanied by an increase in CO2 and a decrease in Arctic sea ice, both of which – based on physical theory and geological analogues – would be expected to warm the climate44. Various lines of evidence, reviewed by the Intergovernmental Panel on Climate Change clearly show that a large part of the modern increase in CO2 is the result of burning fossil fuels, with some contribution from cement manufacture and some from deforestation44. In total, human activities have emitted over 500 billion tonnes of carbon (hence over 1850 billion tons of CO2) to the atmosphere since around 1750, some 65% of that being from the burning of fossil fuels18,45,46,47,48. Some of the carbon input to the atmosphere comes from volcanoes49,50, but carbon from that source is equivalent to only about 1% of what human activities add annually and is not contributing to a net increase.
In the coming centuries, continued emissions of carbon from burning oil, gas and coal at close to or higher than today’s levels, and from related human activities, could increase the total to close to the amounts added during the 55 million year warming event – some 1500 to 2000 billion tonnes. Further contributions from ‘natural’ sources (wetlands, tundra, methane hydrates, etc.) may come as the Earth warms22. The geological evidence from the 55 million year event and from earlier warming episodes suggests that such an addition is likely to raise average global temperatures by at least 5-6ºC, and possibly more, and that recovery of the Earth’s climate in the absence of any mitigation measures could take 100,000 years or more. Numerical models of the climate system support such an interpretation44. In the light of the evidence presented here it is reasonable to conclude that emitting further large amounts of CO2 into the atmosphere over time is likely to be unwise, uncomfortable though that fact may be.
Members of the working group:
Dr C Summerhayes Prof J Lowe
Chairman and GSL Vice-President Department of Geography,
Scott Polar Research Institute, Royal Holloway University of London
Prof J Cann FRS Prof N McCave
School of Earth and Environment, Department of Earth Sciences
Leeds University University of Cambridge
Dr A Cohen Prof P Pearson
Department of Earth and Environmental School of Earth and Ocean Sciences,
Sciences, The Open University Cardiff University
Prof J Francis Dr E Wolff FRS
School of Earth and Environment, British Antarctic Survey,
Leeds University Cambridge
Dr A Haywood
School of Earth and Environment, Ms S Day
Leeds University Earth Science Communicator, GSL
Dr R Larter Mr E Nickless
British Antarctic Survey, Cambridge Executive Secretary, GSL
For those wishing to read further, the following provide an accessible overview of the topic:
Alley, R.B., 2000, The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change, and Our Future. Princeton University Press.
Bell, M. and Walker, M.J.C, 2005, Late Quaternary Environmental Change: Physical and Human Perspectives, (2nd edition). Pearson/Prentice Hall.
Dansgaard, W., 2005, Frozen Annals: Greenland Ice Sheet Research. Neils Bohr Institute, Copenhagen. The book can be downloaded for free from http://www.iceandclimate.nbi.ku.dk/publications/FrozenAnnals.pdf/
Houghton, J., 2009, Global Warming: The Complete Briefing, (4th edition). Cambridge University Press.
Imbrie, J. and Imbrie, K.P, 1979, Ice Ages: Solving the Mystery. MacMillan, London.
IPCC, Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. Available online at http://www.ipcc.ch/publications_and_data/publications_and_data_reports.shtml
Lamb, H.H., 1995, Climate, History and the Modern World, (2nd edition). Routledge, London.
Lovell, B., 2010, Challenged by Carbon: The Oil Industry and Climate Change. Cambridge University Press.
Mayewski, P.A. and White, F., 2002, The Ice Chronicles: The Quest to Understand Global Climate Change. University of New Hampshire/University Press of New England.
Ruddiman, W.F., 2005, Plows, Plagues and Petroleum: How Humans Took Control of Climate. Princeton University Press.
For the more intrepid:
Alverson, K.D., Bradley, R.S. and Pedersen, T.F., (eds.) 2003, Paleoclimate, Global Change and the Future. The IGBP Series, Springer-Verlag, New York.
Burroughs, W.J., 2007, Climate Change: A Multidisciplinary Approach, (2nd edition). Cambridge University Press.
Cronin, T.M., 2009, Paleoclimates: Understanding Climate Change Past and Present. Columbia University Press.
Gibbard, P. and Pillans, B., (eds.), 2008, Special Issue on the Quaternary period/system. Episodes (IUGS Journal of International Geoscience), vol. 31, No.2., (a collection of papers summarising the history of Earth’s environmental and climatic oscillations during the last 2.7 million years).
Langway, Jr., C., 2008, The History of Early Polar Ice-Core records. U.S. Army Corps of Engineers, Research and Development Center. Available online at:
Lowe, J.J. and Walker, M.J.C., 1997, Reconstructing Quaternary Environments, (2nd edition). Addison Wesley Longman Ltd.
Milne, G.A., Gehrels, W.R., Hughes, C.W. and Tamisiea, M.E., 2009, Identifying the causes of sea-level change. Nature Geoscience.
Ruddiman, W.F., 2001, Earth’s Climate: Past and Future. W.H. Freeman.
A collection of articles on various aspects of Rapid Climate Change is available from the proceedings of the National Academy of Sciences web site at: http://www.pnas.org/cgi/collection/rapid_climate
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Reproduced with the kind permission of the Geological Society of London