There was a big conference in Melbourne this week titled Greenhouse 2005: Action on Climate Change . I didn't see much coverage in the national media but The Age ran a feature every day on the perils of climate change to coincide with the event, click here, here and here (and there was more!).
A reader of this web-log was carefully following the dire predictions and sent in the following summary:
2005 may go down in the record books as the warmest year on the global record. What a perfect backdrop for the international Greenhouse 2005 conference held in Melbourne over the last week. 350 delegates from science, industry and government attended for a review of climate change science, likely impacts and strategies for reducing greenhouse gas emissions. The conference saw the who's who of climate change in Australia pouring over the facts and figures and making impassioned speeches on future needs.
The conference was opened by the Governor-General, Michael Jeffrey, who as a "concerned layman" called for action on climate change. General Jeffrey lists melting peat bogs in Russia, storm surges in Florida, and loss of the Antarctic ice sheet as concerns.
The Age reported the GG as "passionate" about the climate change issue. He listed a raft of alternative energy options to be explored - with interestingly nuclear power being one of those options. Setting the tone for the conference the GG said "As a concerned layman, I would suggest the Australian public, to become fully energised on global warming, needs to have a general idea on the answers to the following questions:
* what is the broad global picture in respect to global warming now, and say in 50 years time under projected rates of energy use?;
* what is generally agreed about the warming situation in Australia now and in 50 years time, including its likely impact on our agriculture, weather patterns and general living?;
* What might be the solutions; the way ahead, globally, nationally, and individually?"The Bureau of Meteorology was strong on message that a climate trend was definitely on in Australia: "Australia has experienced its warmest start to a year on record (since 1950), with the January-to-October temperature averaging 1.03 degrees Celsius above the 30-year average (1961-1990). As the year nears an end, a record-breaking year is looking likely - another indicator of climate change. Annual mean temperatures have generally increased throughout Australia since 1910, particularly since the 1950s," says Mike Coughlan, head of the National Climate Centre within the Bureau of Meteorology. As the average temperature has risen, we have also seen an increase in the incidence of hot days and hot nights, and a reduction in the number of cold days and nights. This warming is mirrored in the oceans around Australia.
Warming is not the only sign of change we are observing in Australia's climate. Other changes include a marked decline in rainfall in the south-west and parts of south-east Australia, and recent reductions in rainfall through the eastern states. At the same time, rainfall in the arid interior and north-west has increased dramatically, in some places nearly doubling during the past 50 years."
CSIRO have produced the most precise record of greenhouse gas fluctuations in the Southern Hemisphere over the past 2000 years. They add that the greatest increase in greenhouse gas growth has occurred since the 1980s, with carbon dioxide showing accelerating growth. Other CSIRO researchers such as Penny Whetton warned of changes to extreme weather - more heatwaves, floods, droughts and more intense tropical cyclones. CSIRO are also investigating how climate change interacts with natural short, medium and longer term cycles.
The Australian National University's Dr Will Steffen warned of surprises in the climate system where abrupt climate change may occur in just a few years. Such surprises appear to already exist in the paleo-climate records.
The Age newspaper ran a series of daily feature articles during the week following the conference. Some excerpts are:
The scenario for the Murray River already beset by droughts and ecological concern for its aquatic health suffers a double whammy blow of reduced rainfall and higher evaporation. CSIRO's computer projections have winter rain systems sliding towards Antarctica - a shift that have already started in the last eight years. Droughts become more intense and longer, summer storms are more intense, and heatwaves more common. Environmental flows already provided by river managers may be further eroded as reduced water availability hits home. The Age cites dead and dying riparian vegetation, algal blooms and loss of vertebrate biodiversity. Naturally concerns of irrigators and the environment are on a collision course. CSIRO economist Mike Young says farmers will have to become more adaptive and more climate savvy to swing with increased seasonal variation. As it gets hotter some crops will require more water, crops requiring winter chilling like almonds, apples and cherries may have yield reductions from warmer winter temperatures.At the opposite end of the nation in the iconic Kakadu Park creeping salinsation into the freshwater wetlands has occurred over the last 50 years. While the current cause is not likely to be attributable to climate change further rises in sea level and changes in rainfall pattern will increase and accelerate the trend. The park's paperbark vegetation is thickening up considerably - a combination of increased atmospheric carbon dioxide, changed fire and rainfall regimes are all possibilities. If the system transforms into a salt environment the wetland flora and fauna will go - replaced by mangroves. Some 60 species of water birds are also at stake. The debate about building a barrage to hold back the sea incursion and the salt is on in earnest.
Across on the Queensland coast the Bellenden Kerr range is an ecological island - a refuge of a species assemblage from a cooler and moister Australia of 20 million years ago. A two degree rise would see the wet tropics ecosystem start to disappear with animals needing move upslope to beat the heat. With a 3.5 degree rise 65 species unique to the area would vanish into extinction. If you live at or reach the top of the mountain there is nowhere to go. These is debate about past warm periods but these may have been wetter than today so providing some relief. Can animals genetically adapt to their new environments? Unfortunately it appears that breeding cycles are too long. Some species don't even breed every year and only have a few offspring. The other combinative effect is a change in the cloud forest with the cloud base rising each year. This may not affect water supply to the forest but also affect the water supplies in the Cairns regions.The great Australian icon - the Great Barrier Reef ecosystem has long been feared to be a target of global warming. Certainly even now El Nino events can bleach the corals in the Barrier Reef as well as round the world. When water temperatures become too high coral expel their symbiotic zooxanthellae and die - taking on a white ghostly appearance. Certainly water temperature increases in the lower reef around Heron Island are causing impacts already as the frequency of increased water temperatures increases. In a double whammy the water chemistry of the reef may become more acidic from increased atmospheric carbon dioxide. This threatens the coral's ability to secrete exoskeletons and grow. Can coral's learn to adapt to these new conditions? Certainly experience on other reef systems suggests that coral can expel heat sensitive algae and replace them with heat tolerant strains. But how many species can do this is unknown. Unfortunately a certain amount of warming of the oceans may already be locked in and there will be a steady increase in temperature of the oceans over the next few decades. Certainly there is a lot at stake from an ecological and economic viewpoint.
The other great tourism business in Australia is the skiing industry. The industry is steadily investing in snow making equipment. Maybe it really needs to. Global warming creates a range of basic problems for Australia's 11,500 square kilometre alpine region, a tiny 0.15 per cent of the continent. The most obvious effect of rising temperatures is snow that melts more quickly, is spread thinner, and a snow line that moves higher up the mountain. A complication is rainfall. Under climate change, the winter rain systems are expected to lessen so the chance of snow - even if it is cold enough - drops off. There may be some solace as storms increase, bearing the chance of a big snow dump.
Modelling for 2020 and 2050 shows that the resort with the most remaining snow will be Perisher, in NSW, followed in order by Falls Creek, Mount Hotham, Thredbo and Mount Buller. The smaller resorts of Mount Buffalo, Mount Baw Baw and Lake Mountain become marginal for skiing at 2020, even in the most optimistic scenarios. A report for the Australian Greenhouse Office says further global warming will reduce biodiversity and seriously decrease populations of endemic species. The loss, the report says, will be very significant at a regional, national and international scientific level.
Henrik Wahren, one of Australia's leading alpine ecologists, says the alpine environment could disappear by 2050: "We won't have an alpine area. It will be gone." Once a plant species is lost, he says, there's a cascading effect that flows to insects, birds and animals.
The region clearly has to adapt - selling itself as an alternative to crowded beach resorts may be one such option. Tree change instead of sea change.End of summary.
I would have thought there might be some winners as well as losers out of climate change - that it is not universally all bad. Indeed I have previously commented that warm weather favors coral reefs but not polar bears, click here. But it seems the conference and The Age had a single message: "We'll all be rooned".
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Many thanks to the reader who sent in the long summary - who wishes to remain anonymous.
I would be keen to post a piece that outlined the potential upside of global warming. Any offers?
Ender - I hope you can see that what you thought was not what I said. Certainly not what I was thinking, either.
Thank you for your apology, which I sincerely accept.
Paul - You said "Back onto winners and losers, what about Tasmania, could it be a winner? Lots of high ground, fertile soil, surrounded by water, currently cold. Could easily carry 20million people when the rest of Australia becomes uninhabitable. Something to think about! I believe land is currently quite reasonable, especially on the higher ground."
If Australia becomes uninhabitable then the obvious conclusion here is that it has become unihabited due to our inability to reign in our greenhouse emissions. You then go on to suggest that if this happen we can move to Tasmania. I immediately thought from this that it does not matter what we do the the mainland because we can just move to a now warm Tassie.
Forgive me for this interpretation however it sprang immediately to mind as soon as I read it. To me this is an irresponsible attitude characteristic of my teenager.
In the interests of halting what could go on forever I apologise if that was not your meaning and retract it in this case.
Ender - If you would be kind enough to point out where I have advocated that "we party on now and then when Australia is stuffed we can all move to Tasmania?" I would be happy to withdraw it, as I never remotely suggested or believe it. In fact I did not so advocate.
Any statement can be misrepresented, it is a function of the person doing the misrepresenting, not of the statement itself.
Perhaps you meant misinterpretation? An unclear statement may be open to misinterpretation, although I don't believe my statements were so unclear.
Your continuing posts on this topic are supporting my implication that you lack basic English comprehension skills.
Paul - If your point was open to misrepresentation then perhaps you did not express it properly. In this case you cannot expect not to have the point disputed.
Ender - I was discussing, not advocating. There is a difference, you know.
The point is, if you misrepresent what someone has said, and then make a distasteful comment based on that misrepresentation, you should expect the recipient of that comment to question both your comprehension skills and your manners.
Paul - my comprehension is well up to it so why did you say what you said if you were not advocating and action? I have read your posts - perhaps you have not read mine. The point was when I read your post I immediately thought of my teenager and his behaviour.
Yes there will be winners and losers however nobody can accurately predict where the winners and losers will be. I would not be betting our lives on winning.
Jen - the reduced evaporation story of Roderick and Farquhar is due to particulate pollution making clouds more reflective
http://en.wikipedia.org/wiki/Global_dimming
is worth a read.
If we fix the pollution sources we have have greater radiation (well not greater solar output - just more radiation getting through to the surface) and more temperature increases which will send the evaporation upwards.
Jen - well you asked for it 🙂 - far from settled (but I think we need to know ..!!)
http://www.greenhouse.gov.au/science/guide/
The Australian region spans the tropics to mid-latitudes and has varied climates and ecosystems, including deserts, rangelands, rainforests, coral reefs and alpine areas. The climate is strongly influenced by the surrounding oceans. The ENSO phenomenon leads to alternations between floods and prolonged droughts, especially in eastern Australia. The region is therefore sensitive to the uncertain but possible change toward a more El Niño-like mean state suggested by the TAR.
http://www.sciencemag.org/cgi/content/full/309/5735/758
Permanent El Niño-Like Conditions During the Pliocene Warm Period
Michael W. Wara, Ana Christina Ravelo,* Margaret L. Delaney
During the warm early Pliocene (~"4.5 to 3.0 million years ago), the most recent interval with a climate warmer than today, the eastern Pacific thermocline was deep and the average west-to-east sea surface temperature difference across the equatorial Pacific was only 1.5 ± 0.9°C, much like it is during a modern El Niño event. Thus, the modern strong sea surface temperature gradient across the equatorial Pacific is not a stable and permanent feature. Sustained El Niño-like conditions, including relatively weak zonal atmospheric (Walker) circulation, could be a consequence of, and play an important role in determining, global warmth.
http://www.grida.no/climate/ipcc_tar/wg1/361.htm
ENSO is associated with some of the most pronounced year-to-year variability in climate features in many parts of the world (Chapters 2 and 7). Since global climate models simulate some aspects of ENSO-like phenomena (Chapter 8), there have been a number of studies that have attempted to use climate models to assess the changes that might occur in ENSO in connection with future climate warming and in particular, those aspects of ENSO that may affect future climate extremes.
Firstly, will the long-term mean Pacific SSTs shift toward a more El Niño-like or La Niña-like regime? Since 1995, the analyses of several global climate models indicate that as global temperatures increase due to increased greenhouse gases, the Pacific climate will tend to resemble a more El Niño-like state (Knutson and Manabe, 1995; Mitchell et al., 1995; Meehl and Washington, 1996; Timmermann et al., 1999; Boer et al., 2000b). However, the reasons for such a response are varied, and could depend on the model representation of cloud feedback (Senior, 1999; Meehl et al., 2000b); the quality of the unperturbed El Niño state in the models (Chapter 8) or the stronger evaporative damping of the warming in the warm pool region, relative to the eastern Pacific due to the non-linear Clausius-Clapeyron relationship between temperature and saturation mixing ratios (e.g., Knutson and Manabe, 1995). Additionally, a different coupled model (Noda et al., 1999b) shows a La Niña-like response and yet another model shows an initial La Niña-like pattern which becomes an El Niño-like pattern due to subducted warmed extra-tropical water that penetrates through the sub-tropics into the tropics (Cai and Whetton, 2000). A possible reason for the La Niña-like response has been suggested in a simple coupled model study where the dominant role of ocean dynamics in the heat balance over the tropical Pacific is seen for a specified uniform positive forcing across the Pacific basin (Cane et al., 1997).
Figure 9.26: Standard deviations of Niño-3 SST anomalies (Unit: °C) as a function of time during transient greenhouse warming simulations (black line) from 1860 to 2100 and for the same period of the control run (green line). Minimum and maximum standard deviations derived from the control run are denoted by the dashed green lines. A low-pass filter in the form of a sliding window of 10 years width was used to compute the standard deviations. (a) ECHAM4/OPYC model. Also shown is the time evolution of the standard deviation of the observed from 1860 to 1990 (red line). Both the simulated and observed SST anomalies exhibit trends towards stronger interannual variability, with pronounced inter-decadal variability superimposed, (reproduced from Timmermann et al., 1999), (b) HadCM3 (Collins, 2000b).
Secondly, will El Niño variability (the amplitude and/or the frequency of temperature swings in the equatorial Pacific) increase or decrease? Attempts to address this question using climate models have again shown conflicting results, varying from slight decreases or little change in amplitude (Tett 1995; Knutson et al., 1997; Noda et al., 1999b; Collins, 2000b; Washington et al., 2001; Figure 9.26b) to a small increase in amplitude (Timmermann et al., 1999; Collins, 2000a; Figure 9.26a), which has been attributed to an increase in the intensity of the thermocline in the tropical Pacific. Knutson et al. (1997) and Hu et al. (2001) find that the largest changes in the amplitude of ENSO occur on decadal time-scales with increased multi-decadal modulation of the ENSO amplitude. Several authors have also found changes in other statistics of variability related to ENSO. Timmermann et al. (1999) find that the interannual variability of their model becomes more skewed towards strong cold (La Niña type) events relative to the warmer mean climate. Collins (2000a) finds an increased frequency of ENSO events and a shift in the seasonal cycle, so that the maximum occurs between August and October rather than around January as in the unperturbed model and the observations. Some recent coupled models have achieved a stable climate without the use of flux adjustments and an important question to ask is what is the effect of flux adjustment on changes in variability. Collins (2000b) finds different responses in ENSO in two models, one of which has been run without the use of flux-adjustments. However, he concludes that differences in response are most likely to be due to differences in the response of the meridional temperature gradient in the two models arising from different cloud feedbacks (Williams et al., 2001) rather than due to the presence or absence of flux adjustment.
Finally, how will ENSO’s impact on weather in the Pacific Basin and other parts of the world change? Meehl et al. (1993) and Meehl and Washington (1996) indicate that future seasonal precipitation extremes associated with a given ENSO event are likely to be more intense due to the warmer, more El Niño-like, mean base state in a future climate. That is, for the tropical Pacific and Indian Ocean regions, anomalously wet areas could become wetter and anomalously dry areas become drier during future ENSO events. Also, in association with changes in the extra-tropical base state in a future warmer climate, the teleconnections to mid-latitudes, particularly over North America, may shift somewhat with an associated shift of precipitation and drought conditions in future ENSO events (Meehl et al., 1993).
When assessing changes in ENSO, it must be recognised that an “El Niño-like” pattern can apparently occur at a variety of time-scales ranging from interannual to inter-decadal (Zhang et al., 1997), either without any change in forcing or as a response to external forcings such as increased CO2 (Meehl and Washington, 1996; Knutson and Manabe, 1998; Noda et al., 1999a,b; Boer et al., 2000b; Meehl et al., 2000b). Making conclusions about “changes” in future ENSO events will be complicated by these factors. Additionally, since substantial internally generated variability of ENSO statistics on multi-decadal to century time-scales occurs in long unforced climate model simulations (Knutson et al., 1997), the attribution of past and future changes in ENSO amplitude and frequency to external forcing may be quite difficult, perhaps requiring extensive use of ensemble climate experiments or long experiments with stabilised forcing (e.g., Knutson et al., 1997).
Although there are now better ENSO simulations in global coupled climate models (Chapter 8), further model improvements are needed to simulate a more realistic Pacific climatology and seasonal cycle as well as more realistic ENSO variability (e.g., Noda et al., 1999b). It is likely that such things as increased ocean resolution, atmospheric physics and possibly flux correction can have an important effect on the response of the ENSO in models. Improvements in these areas will be necessary to gain further confidence in climate model projections.
Jen - more El Ninos is a "moderate confidence" prediction - need to dust off some papers - will get back.
Evaporation - what governs evaporation - temperature, radiation and wind. Temperature will be up. Radiation may indeed be up if we get rid of global dimming factors - particulate pollution. Clouds may be a factor conceded.
So it depends how it works out in the overall balances does it not. Clouds and aerosols are active areas of current research to improve.
Of course with EL Nino evenst one tends to have cloud free conditions.
Interesting droughts in Australia have becoming hotter with the Bureau commenting the 2002-03 drought had a severity added by greenhouse warming.
http://www.dar.csiro.au/publications/hennessy_2003b.pdf
So the increase in the evaporative flux made 2002 drought more severe than the severity of the Federation drought (of course it's a severity x duration x area affected shoot-out for those wanting to compare such things).
In terms of confidence of "projections" - warming is high, higher intensity rainfall events and more intense cyclones is pretty confident. Rainfall/evaporation balance still needs to be nailed down much better- but as I understand it for Qld most models point to high evaporative demand.
If you were an amatuer punter (Caveat: I'm a mug punter) - I think the greater frequency of Los Ninos and changes in southern hemisphere circulation patterns (sub tropical ridge) are of some concern when you look at the last decade of water shortages and last 15 years of drought.
Phil
1. On what is the prediction of more El Nino events based? This phenomena can be seen in the coral bleaching record back to at least the 1400s.
2.Also I can't work out why evaporation will be higher - given it will be cloudier? My understanding is that the models say increased evaporation but actual measurements show decreased.