Climate Change: Consensus or Controversy?A view from the Antipodes

Neville Nicholls

Bureau of Meteorology Research Centre

Melbourne, Australia

Some data, some science, and some culture

“That’s the IPCC, as you know – a huge group of bureaucrats, and scientists under the thumb of bureaucrats”

“The first tornado ever to hit Australia has destroyed half a dozen villages”

…and in the Aussie op-ed pages….

Global dimwits“Time to panic, the world's getting hotter ... and colder. Doesn't make sense? Doesn't matter, it's another Green scare campaign.”Andrew Bolt, Herald Sun, 25 March 2005

Age of no reason“Want to make a greenie boil? Just question their claims of global warming. It's not hard when so much of the evidence is paper thin.”Andrew Bolt, Herald Sun, 18 February 2005

Wet and wild but no proof of calamity“…the jury is still out on the impact of man-made intervention.”Tony Baker, The Advertiser, 22 June 2005

Howard dishes up greens“One of the alternative explanations [to the enhanced greenhouse effect] is that the main cause has been volcanic activity, much of it submarine and hard to detect.”Christopher Pearson, The Australian, 11 June 2005

Warming debate cooling“Not only is the scientific community not in agreement about the causes of global warming, but studies at the University of East Anglia show average global temperature has declined since 1998.”Neil Coulson, Herald Sun, 01 July 2005

…and even some Aussie scientists.Global warming cyclical so forget Kyoto, says climate expert“The United Nations Intergovernmental Panel on Climate Change has been the main scaremonger for the global warming lobby…Fatally, the IPCC is a political, not a scientific body.”Professor Rob Carter, quoted in The Age, 13 June 2005

When politics engulfs science…“Carbon dioxide concentrations cannot be shown to have any appreciable effect on future climate…”William Kininmonth, The Age, 8 July 2005

Australian Financial Review, 4 August 2005

“Heat and low rainfall are one of the reasons climate change has become such a big political issue in Europe. As the weather changes fast, and fears grow that it will get faster and much worse, it’s also the reason Europeans are quickly raised to anger when the issue of the United States, Australia and the Kyoto Treaty comes up.”

Canberra in denial over greenhouse

“The Howard Government has denied global warming exists, or that burning coal releases greenhouse gases that lead to climate change, in court documents defending its approval of two Queensland coalmines.” The Age, 11 August 2005

                            

 

Common arguments from “sceptics”:

The greenhouse effect is just a theory. In the 1970s scientists were predicting an ice age. The warming is just due to urban heating. We can’t predict the weather a week in advance,

so how can we do it 100 years in advance? Satellites (and some stations) show no warming. It’s just natural variability. The warming is pretty small or unimportant

anyway.

Common arguments from “sceptics”:

The greenhouse effect is just a theory. In the 1970s scientists were predicting an ice age. The warming is just due to urban heating. We can’t predict the weather a week in advance,

so how can we do it 100 years in advance? Satellites (and some stations) show no warming. It’s just natural variability. The warming is pretty small or unimportant

anyway.

A geography of climate, J. Gentilli, Univ. Western Australia, 1952

“It follows that the atmosphere lets incoming (solar) radiation through much more easily than outgoing (terrestrial) radiation. This is called the selective or “greenhouse” effect of the atmosphere.”

Common arguments from “sceptics”:

The greenhouse effect is just a theory. In the 1970s scientists were predicting an ice age. The warming is just due to urban heating. We can’t predict the weather a week in advance,

so how can we do it 100 years in advance? Satellites (and some stations) show no warming. It’s just natural variability. The warming is pretty small or unimportant

anyway.

Climatologists were aware of threat of global warming, even in the 1970s:

“My feeling is that if man’s interferences with the climatic system is uncontrolled for some decades, together with uncontrolled growth of energy use, sooner or later during the next century the warming will overwhelm natural factors which usually produce cooling”H. Flohn, discussion at Monash Univ., December 1975

Climate scientists were predicting warming even in the 1970s:

“For global mean conditions, a surface temperature rise of about 2K was obtained for a doubling of the carbon dioxide amount…”Hunt & Wells, J. Geophysical Res., 1979

“…our best estimate of the temperature rise which might be expected with a doubling of the atmospheric CO2 concentration is about 2-3°C…”G.I.Pearman, in Climatic change and variability. A southern perspective, CUP, 1978

Climatologists were aware of threat of global warming, even in the 1970s:

“Numerical modelling…predicts that a 10 per cent increase in the current CO2 concentration would cause a surface temperature increase of about 0.3°C.”Report of a Committee on Climatic Change, Australian Academy of Science, 1976

1976 Academy Report suggests warming of ~0.45°C, if CO2 increased by 15%.

Annual Global Temperature Anomaly

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1856 1866 1876 1886 1896 1906 1916 1926 1936 1946 1956 1966 1976 1986 1996

Year

Tem

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mal

y (C

)

~0.45C

2000

1976

Observed warming of ~0.45°C

Common arguments from “sceptics”:

The greenhouse effect is just a theory. In the 1970s scientists were predicting an ice age. The warming is just due to urban heating. We can’t predict the weather a week in advance,

so how can we do it 100 years in advance? Satellites (and some stations) show no warming. It’s just natural variability. The warming is pretty small or unimportant

anyway.

Macquarie Island, c.1913

Someone’s backyard

http://www.bom.gov.au/silo/products/cli_chg/index.shtml

Australian annual mean maximum temperature

Annual temperature anomalies - Australia

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MaxT 11 per. Mov. Avg. (MaxT)

Australian annual mean maximum & minimum temperature

Annual temperature anomalies - Australia

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1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

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MaxT MinT 11 per. Mov. Avg. (MinT) 11 per. Mov. Avg. (MaxT)

Australian annual mean maximum & minimum temperature & SST (45-10°S, 110-160°E)

Annual temperature anomalies - Australia

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1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

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MaxT MinT SST 11 per. Mov. Avg. (SST) 11 per. Mov. Avg. (MinT) 11 per. Mov. Avg. (MaxT)

Macquarie Island & surrounding SSTsMacquarie Island

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1951 1956 1961 1966 1971 1976 1981 1986 1991 1996 2001

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y, 5

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Observed ocean warming since 1960 at various depths (red dots) and range of warming ( green) predicted by 5 simulations of the PCM (Barnett et al., 2005)

The Qori Kallis Glacier in the Peruvian Andes

Argentina's Upsala Glacier is retreating at a rate of 200m per year.

Measured variations in the position of the termini of the Fox, Franz Josef, and Ivory Glaciers. http://pubs.usgs.gov/prof/p1386h/nzealand/nzealand.html#fig6

Common arguments from “sceptics”:

The greenhouse effect is just a theory. In the 1970s scientists were predicting an ice age. The warming is just due to urban heating. We can’t predict the weather a week in advance,

so how can we do it 100 years in advance? Satellites (and some stations) show no warming. It’s just natural variability. The warming is pretty small or unimportant

anyway.

We can’t predict the weather a week in advance, so how can we do it 100 years in advance?

Analogous to playing two-up:We cannot predict the result of the 1000th tossBut we know two heads will turn up 25% of the time

Aboriginal bush calendar 2002

Traditional calendar, coastal Arnhem Land

And we can “predict” the climate.

Jevons, 1859

"These are all instances of the Meteorological simplicity of Australia, corresponding as one is tempted to exclaim, with its simplicity or monotony in other respects." Jevons, 1859

Common arguments from “sceptics”:

The greenhouse effect is just a theory. In the 1970s scientists were predicting an ice age. The warming is just due to urban heating. We can’t predict the weather a week in advance,

so how can we do it 100 years in advance? Satellites (and some stations) show no warming. It’s just natural variability. The warming is pretty small or unimportant

anyway.

MSU tropospheric temperature trends

Trend1979-2004

1979 2004

Black: RSSBlue: SurfaceYellow: UAHRed: FuPink: V&G

…and some stations don’t exhibit warming…Alice Springs

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1879 1889 1899 1909 1919 1929 1939 1949 1959 1969 1979 1989 1999

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(Michael Crichton uses Alice Springs as an example)

…unless you take changes and moves into account…Alice Springs

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1879 1889 1899 1909 1919 1929 1939 1949 1959 1969 1979 1989 1999

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Stevenson screensupplied

Move to airport Move at airport

…but doesn’t mention shifts and changes…

…unless you take changes and moves into account…

…but doesn’t mention shifts and changes…

Alice Springs

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1879 1889 1899 1909 1919 1929 1939 1949 1959 1969 1979 1989 1999

Year

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Stevenson screensupplied

Move to airport Move at airport

…but who was Alice?

Charles Todd

Charles & Alice Todd

Adelaide Observatory, late 19th century

Impact of change from Glaisher stand to Stevenson screen - Adelaide

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Nicholls et al., 1996

Common arguments from “sceptics”:

The greenhouse effect is just a theory. In the 1970s scientists were predicting an ice age. The warming is just due to urban heating. We can’t predict the weather a week in advance,

so how can we do it 100 years in advance? Satellites (and some stations) show no warming. It’s just natural variability. The warming is pretty small or unimportant

anyway.

Russell Drysdale

PCM

Courtesy: Julie Arblaster, Gerry Meehl

Karoly2

Trends in Australian-average mean temperature from anthropogenically forced (GS, open symbols) and natural externally forced (NAT, solid symbols) model simulations and observations during 1950–99 and 1910–99. (Karoly & Braganza, 2005)

http://www.bom.gov.au/silo/products/cli_chg/index.shtml

NSW annual mean

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1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Year

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mm

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Ma

xT

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)

Time series of annual mean maximum temperature (red) and annual rainfall (blue) for New South Wales, 1910-2002. Eleven-year running means (centred) are shown as thick lines. Note that the temperature scale (right hand side) is inverted.

Nicholls et al., 2004

Why did NSW cool thru the 20th century?

Common arguments from “sceptics”:

The greenhouse effect is just a theory. In the 1970s scientists were predicting an ice age. The warming is just due to urban heating. We can’t predict the weather a week in advance,

so how can we do it 100 years in advance? Satellites (and some stations) show no warming. It’s just natural variability. The warming is pretty small or unimportant

anyway.

Australian average number of hot days (daily maximum temperature ≥ 35°C), cold days (daily maximum temperature ≤ 15°C), hot nights (daily minimum temperature ≥ 20°C) and cold nights (daily minimum temperature ≤ 5°C) per year. (Nicholls & Collins, 2005)

Murray-Darling Basin May-October Means

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1952 1957 1962 1967 1972 1977 1982 1987 1992 1997 2002

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Rai

nfa

ll (m

m)

Mean maximum temperature ~1C warmer than previous record for 1952-2001 period

Mean minimum temperature much warmer than in previous similar droughts (1982, 1994)

Nicholls, 2004

Spencers Creek snow depthJuly-Sept mean maximum temperature Cabramurra

Snow depth first observation in October

1962 1967 1972 1977 1982 1987 1992 1997 2002

Year

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ture

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Sno

w d

epth

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)

Australian Alps spring snow depth has declined 40% since 1960, due to warming

Nicholls, 2005

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1840 1860 1880 1900 1920 1940 1960 1980 2000

Year (A.D.)

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MS

A (m

M)

SIE

( oS)

Mark A. J. Curran, Tas D. van Ommen, Vin I. Morgan, Katrina L. Phillips and Anne S. Palmer. Ice Core Evidence for Antarctic Sea Ice Decline Since the 1950s, Science, 302: 1203-1206, 2003.

Blue curves, methane sulphonic acid (MSA) concentrations in Law Dome ice core (smoothed 1, 3, 20 year moving average). Red curve satellite sea-ice extent (3 year moving average)

Antarctic sea-ice extent has declined

Changes in mean sea level result in changes in the frequency and intensity of extreme events

For Fremantle a 1 in 5 year event has

become a 1 in 2 year event.

John Hunter

…recent break-up event is unprecedented in the Holocene history of this glacial system. The ice shelf's demise is probably the consequence of a combination of long term thinning (by a few tens of metres) over thousands of years and short term (multi-decadal) cumulative increases in surface air temperature that have exceeded the natural variation of regional climate during the Holocene interglacial. Domack et al., Nature, 2005)

Larsen B ice-shelf

Common arguments from “sceptics”:

The greenhouse effect is just a theory. In the 1970s scientists were predicting an ice age. The warming is just due to urban heating. We can’t predict the weather a week in advance,

so how can we do it 100 years in advance? Satellites (and some stations) show no warming. It’s just natural variability. The warming is pretty small or unimportant

anyway.

Gerry Hueston, President, BP Australasia3 August, 2005

“It would be too great a risk to stand by, do nothing, and to wait so long that when the impact on the climate really does begin to be felt we have to collectively take action which is so disruptive that it causes serious damage to the world’s economy”