Australia at plus 4°C: Not so hot
Of all the players in Australia's climate policy debate, farmers might have the right to feel among the most maligned. Since the release on Sunday of the federal government's carbon pricing package, the agricultural industry has been crying foul, arguing that the government has picked a scheme that will add to farmers' costs, and erode the average net farm income by 2.4 per cent, without necessarily making a big enough impact on emissions. Meanwhile, in Melbourne this week, climate scientists warned that if the world was to keep warming at its current rate, then farming as we know it in Australia would be untenable by 2100.
In the global warming stakes, "Australia is probably the most vulnerable continent," said Hans Joachim Schellnhuber – from the Potsdam Institute for Climate Impact Research in Germany – in his opening address to the Four Degrees or More? Australia in a Hot World conference in Melbourne this week. And according to another of its speakers, the CSIRO's Penny Whetton, the most vulnerable parts of Australia in a warming world – where the changes in climate would be most striking – are its agricultural centres, like the Murray-Darling Basin, and wheat-belt towns, like Dubbo in NSW.
At the conference on Tuesday, and then later on ABC's Lateline, Schellnhuber used the analogy of human body temperature to convey how much damage a seemingly minor increase in the earth's temperature could do. "Our body temperature is about 37 degrees. If you increase it by two degrees, 39, you have fever. If you add four degrees, it is 41 - you are dead, more or less," Schellnhuber said. "And you have to think about the body temperature of our planet, which has been brought about through many, many processes over many, many millions of years. So, disturbing our planet at such an amount would, as I said before, create a different world, it would mean agriculture would have to find completely new ways.
"And, by the way, Australia is surrounded by oceans – four degrees sustained for a while would mean at least seven or 10 metre sea level rise; probably it would melt down all the ice on this planet. That accounts to 70 metres, seven-0 metres, in the long term."
The fact that the melting of the Greenland ice sheet should translate to rising seas mainly in the Pacific, with island nations bearing the brunt – and decreased sea levels around Greenland, due to its decreased gravitational pull – is part of what Schellnhuber refers to as the "injustice" of climate impacts.
And he says that warming of between 2-4°C would also result in increased "precipitation injustice," a phenomenon that Australians are already keenly aware of.
According to David Karoly, a professor at the University of Melbourne’s School of Earth Sciences, at 4°C there would be likely declines in annual rainfall of up to about 50 per cent in southern Australia. And with only 2°C of warming, combined with increases in annual potential evaporation of between 5-20 per cent, the frequency of drought in the Murray-Darling Basin would more than double, while in Victoria it would quadruple.
In a joint presentation at the conference Tuesday, Karoly and Whetton painted a 4°C scenario for Australia with temperature increases of about 3-5°C in coastal areas, and 4-6°C in inland areas. Whetton said that at 4°C of warming, towns in eastern Australia would basically adopt the climates of their northern neighbours. With Melbourne's weather patterns shifting to be more like those of the southern Flinders Ranges, or mid-west NSW; Sydney, "best case," adopting Brisbane's climate, "worst case," that of the Atherton Tablelands; Brisbane becomes far north Queensland; Cairns, more like Weipa; and for Darwin, said Whetton, not only could they not find the projected climate for Darwin anywhere in Australia, they couldn't find it anywhere in the world. As for Perth, well that becomes basically unliveable.
Drastic changes in snow cover would be another impact from 4°C warming. Despite much-celebrated heavy snowfalls in Victoria this winter, Karoly says that the long term observations of scientists have noted "dramatic declines" in the number of days with snowfall on the ground. In the worst-case scenario, with unabated warming, "your grandchildren may not be able to ski in Australia in 40 years time," Karoly said.
This is not good news for Australia's tourism industry, which this week complained of being another victim of the proposed carbon pricing package. Australian Tourism Export Council managing director Felicia Mariani was quoted in The Sydney Morning Herald on Tuesday as saying that tour operators such as highly fuel-dependent dive companies on the Great Barrier Reef would face particular hardship under the new fuel taxes, with no way to claim compensation.
But speaking at the conference, Schellnhuber pointed to this very news story as one of the many metaphors to be found in the press for the alarming short-sightedness in the Australian climate debate: That tour companies on the Great Barrier Reef should bemoan the costs of a measure designed to save from ruin the very source of their livelihood.
Indeed, the 4°C scenario for the world's oceans – and the countless ecosystems they support – looks particularly grim. According to Malte Meinshausen – a colleague of Schellnhuber's at the Potsdam Institute who has come to Australia to join the University of Melbourne's School of Earth Sciences – the global warming "triple whammy" of increased temperatures, acidification and decreased oxygen levels that threatens the world's oceans is "possibly one of the biggest problems of the 21st Century." Meinshausen stresses that while nature causes the variability in climate – "the ups and downs" – mankind causes the increases. And he says that by continuing with business-as-usual with our emissions, we are not just loading the dice for the increased frequency of extreme weather events, but "putting more dots on the dice."
"Future emissions are not uncertain," Meinshausen told the conference on Tuesday – "they are our choice." And this is "the critical decade to take our foot off the accelerator," he said. Because "the best we can hope for [a 2°C scenario] is scary enough."
And Schellnhuber agrees. "Climate change, ultimately, is a threat to our biological health and survival," he told the conference – pointing to the various populations and ethnicities in the Pacific region and around the Himalayan glaciers that would be under threat from both 2°C and 4°C scenarios. And "losing an entire culture," he said, "is a highly nonlinear event."
Comments on this article
More ancient warming periods and glacial periods
In response to Peter Lang:
Peter,
I believe that you are right, in the 4 billion years of the earth's existence it has been more often warmer, than colder than now.
The current ice "age", the Quaternary, has been going for only 2.6Ma, not 10Ma as I suggested.
I'm not happy about comparing current temperatures with the far past, especially before the Karoo ice age (360-260Ma).
Oxygen only became a significant component of our atmosphere 600Ma. Once the % was near 15%, about 550Ma, oxidation of iron kept it close to 15% for two hundred million years. Then it exploded during the Karoo/Carboniferous, reaching 35% before the Permian Triassic (P-T) Event where atmospheric O2 dropped back to 15%. Then it rose back slowly to 30%, before falling away after the Cretaceous-Tertiary (K-T) Event (65Ma) to the 21% we have now.
I figure that if our atmosphere, the moon, plant life, animal species etc, were so different in those periods, what is the point of a comparison?
A 4C rise is significant. It is extremely unlikely to cause an extinction event. Most species will adapt, including us. We will have no choice. The bioshere will adapt, but it wont be immediate. The great prairies of Nth America did not spring up overnight when the glaciers retreated. 2.4 metres of topsoil took many thousands of years of bison grazing.
The bigger the rise the harder adaptation will be. If we dont stop burning fossil fuels, it wont be 4C we adapt to. It will be 5, 6, or more.
97.5% of climatologists agree man made global warming is serious
Actually it's not 84% of climate scientists, more like 97.5% agree global warming is being forced by human emissions and here's the proof:
http://tigger.uic.edu/%7Epdoran/012009_Doran_final.pdf
Some sense
Thanks Bruce, it's nice to someone has some sense
Ask the right questions for a change
The question isn't what makes you think it will warm by 4 degrees, but what makes you think that it won't.
Nobody arguing here seems to remember that this experiment isn't being conducted in a benchtop jar. <b>We are in the experiment</b> and there is no way for us to escape the results.
Not once have I heard any mention of the precautionary principle on these pages.
This should certainly colour our response to potential threats.
The idea that we can comehow go on burning coal forever is a fiction. Even if the environment could take it, the coal seams won't last very long. It's more like 50 years of coal than 500, especially when the grand expansion plans are considered.
No matter that the AGL lobby thinks, the human race will be living witih its means within 100 years, probably this willbe closer to 50.
Lord Mockton
Lord Monckton is actually an alien from planet Lizard Ogled. He has come here deceive us, as the alien life forms from whence he comes, need to have a hotter environment. I know this to be true, because I believe it. Can anyone prove me wrong? I bet you can't. After all Monckton, says the plant actually cooled in the last decade when the all data from trusted sources say it actually got hotter. I am confused then, why are more and more people buying air conditioners, if our summers are getting cooler. Oh such is the paradox !
Wrong.
"...85% of published climate scientists disagree with the denialist lay-people posting below..."
Rubbish. A regurgitated and fraudulent wikistat.
Care to back your statement up with evidence?
How many are 'climate' scientists?
Take your time.
Food and population is the real issue
When resources are squeezed aren't a hell of a lot of people simply going to starve? Maybe mother nature is programmed to rid the planet of feral plagues.
David leComte – The world is usually warmer not colder
You said, wrongly, "The world is usually colder not warmer”
You selected a short (10 million year) period during a cold phase. That it is a cold phase is obvious because it is one of those rare times when there are polar ice caps (only three previous times in the past 500 million years. The fact is that when the planet is warmer (no ice caps) life thrives and when colder life struggles.
Cherry picking of time periods to support your case is common by those preaching catastrophic consequences of global warming. It does not give me confidence about what we are being told.
Bernard Walsh, "you're missing the point, Peter"
Bernard Walsh,
Thank you for your reply. In reply to me you said:
“The "rapid" warmings you're talking about in the deep past took tens of thousands of years.”
No. I am referring to the rapid changes that occur over years and decades. For example, Greenland warmed by 16 degrees in a decade (from memory). It became green. Life thrived. There are many examples of rapid warming (and cooling). Life loves the warming but hates the cooling.
Warmer is better. Look at the past. So why the big scare?
Certain "injustice"
A 4 degree celsius rise over the next 89 years works out to 0.45 degrees celsius per decade. That seems a little high when the IPCC is only quoting 0.15 degrees per decade. The UAH satellite data since 1979 shows a 0.4 degree rise over the last 3 decades, so that's about 0.13 degrees per decade. It's generally accepted that we've had a 1 degree celsius rise over the last 150 years and this works out to about 0.066 degrees per decade. Any suggestion that the rate of warming is increasing due to our increased emissions is refuted by the satellite data for the last decade which shows a flat trend or slightly less than a zero degree rate of warming.
An early IPCC graph from their 1995 report, showed the Medieval Warming Period as hotter than the late 20th century. Lead IPCC author Phil Jones has admitted the possibility that the Medieval Warming Period of around 1000 years ago may have been warmer than today, in which case the only certain "injustice" that threatens mankind, is a carbon tax or emissions trading scheme.
John, why spend the whole
John, why spend the whole blog on 'to ignore .. opinions of experts', when I stated "accept ...opinions on face value"?
Siberia
So are you volunteering to relocate?
I'd rather reduce my carbon emissions now, thank you very much. But it's encouraging to see you realise the future of humankind is at stake, Paul.
The future climate of the
The future climate of the Russian Steppes is a moot point as much of the area's soils have been significantly depleted and eroded by agricultural clearing of what little cover the land possessed in the 19th Century. Man has already been there and left his mark.
Ag
Paul has a good point. Australia may be a large net exporter of ag product but we are a small producer in a global sense. The 5 counties surrounding Fresno CA (200km radius) in the US have a combined Ag output greater than Australia's entire production value.
Still, it's not a good plan to place our country's food security in the hands of the Russians or anyone else for that matter. It is in our interest to be a global agent of change if we can. Hopefully Australians left fatalism behind when our ancestors arrived as immigrants.
Siberia
Find a map of the World, look at the amount of land in the Northern Hemisphere that is currently non/low productive because the growing season is too short, factor in a 4c rise and imagine what that will do for food production (and before somebody says it is crap land, check your facts, most of it is prime agricultural). Australia may be a big country but 80% of it is already desert, the Russian Steppes will easily make up for any loss we have here. And while we are at it, how can somebody concerned about a Global issue be so parochial !, its the continuing existance of the Human race thats at stake here; or arn't you prepared to make sacrifices yourself ?
In response to "Where's La Nina"
The effect of climate warming on the Southern Oscillation Index (El Nino/La Nina cycle) is not really known.
The consensus seems to be that the cycle rate may change, and the peak magnitude of the cycles may increase. The "hand-waving" argument is that by increasing the energy going into the ocean one is potentially increasing the temperature differences leading to faster currents. Faster currents and bigger temperature differences mean a bigger "oscillation".
There are at least two effects on the average earth temperature, whose magnitude dwarfs the year-year variation of GW. These are the Southern Oscillation Index and the 11-year solar cycle.
Whilst the depth of the last El Nino, the weakness of several La Nina periods, and the strength of the current one, support the idea that GW may cause an increase in the size of the Index, my reading of the available literature leads me to think that we may have to wait another 15-30 years before making any kind of conclusion.
Siberia
CSIRO estimates that global warming will not be good for agriculture-as-we-know-it in Australia. Yet Paul is happy because 4°C of warming will make it so much nicer in Siberia.
Even if Siberians will benefit - good luck to them for trying to grow crops on that soil - what good is that to Australians?
And Peter waves off genuine concerns by scientists who studied the matter as "exaggerated at best, alarmism and scaremongering at worst". Based on what? Wishful thinking alone won't really do.
I'm sure many more people struggle with the catastrophic consequences claims about global warming. Denial is the first reaction for many, but I'm hoping a majority of us will get beyond that destructive reaction.
Qualified?
Ian, in order to ignore 'learned opinions' of experts, people must be sufficiently learned themselves in the discipline. A lay-person has no chance of acquiring data and analysing it effectively to arrive at a self-studied opinion that carries any weight. This is why we must rely on the majority of peer-reviewed scientific opinion for policy. Your (and my) opinion is not peer reviewed nor is it exposed to any alternative form of verification. So why should anyone listen to it? They shouldn't. They should trust the CSIRO and others who have made the study of this their life.
This is what we do every day when we ask doctors about our health, accountants about our finances, teachers about our kids schools, and dentists about our teeth. We may not like the first opinion we get, nor the second... but by the tenth, if the experts are mostly saying the same thing, we listen and act on their advice. Like I keep saying, if 8 out of 10 oncologists told me I had cancer, I would act because they are the experts. I don't have time to go back to uni and self diagnose.
Time we start doing the same on climate change because every voter can't get a PhD in climatology like you have.
The world is usually colder not warmer
In response to Peter Lang - "I struggle with the "Catastrohic consequences" claims.
There is some substance to your claims, but some errors.
Firstly, the planet, for the last 10 million years has generally been colder than now. Warm ages are roughly 9 times smaller than Ice ages. We are in a warm interglacial period. Given the cyclic behaviour of these ice-ages, we should be entering another ice-age in the next few thousand years.
Some of the claims in this article are alarmist.
In any environmental change, there are winners and losers. In the short-term, rapid climate changes are always associated with species loss. It takes a long time for the biosphere to react.
To talk of Greenland as being a "win" for agriculture is to ignore the loss of arable land elsewhere. It also ignores the fact that there is no "top-soil" under the Greenland ice sheet; glaciation has scoured the land down to bedrock.
Top soil takes a long time to build up.
In response to Paul Rainbow (Luddites)
That we will have to adjust to significant temperature changes is without question.
If we were nomadic hunter-gatherers that would be relatively easy. Our tribes may reduce in size, and we may end up walking half-way across Australia, but, as humans, we would adapt.
But as another person indicated, there are 7 billion of us, so it is not going to be so easy - yet we will have to do it.
But your argument is that if we have to adjust to a 4C rise anyway, then lets not do anything? What temperature rise will you be happy with 6C, 8C, 10C?
The higher the rise we allow to happen, the harder the adjustment will be.
Also why do you write "there will be a lot more land available"? How do you know that the increase in desertification will be compensated by the increase in agricultural productivity of what is now tundra?
Your arguments are non-sensical.
To those who accept the
To those who accept the interpretations of '85% of climate scientists', the US Congress-sponsored Wegman Report (2006) into the jolly hockey stick of Dr. Mann had this to say: "....at least 43 authors have direct ties to Dr. Mann by virtue of co-authored papers with him. Our findings from this analysis suggest that authors in the area of palaeoclimate studies are closely connected and thus 'independent studies' may not be as independent as they might appear on the surface."
The maxim is accept 'learned opinions' on face value, look at the data they use, carefully, and then make up your own minds.
In response to Max Godfrey
Your analogy Max, is approriate for Arctic ice, which is floating in the Arctic ocean.
The analogy is not appropriate for the ice sheets in Greenland, Alaska, the Canadian North-West Territories, and the largest of all, the Antarctic ice sheet. These are on land.
A better analogy for the melting of land-based ice, is to place ice cubes in a glass with water, the water level will rise by 6/7ths of the volume of the ice (melted or not).
But dont despair too much(yet). There is a lot of latent heat in these land-based ice sheets. There is typically, (and approximately) a 1000 year lag between warming and cooling periods, and the Antarctic ice sheet retreating and growing.
The Greenland ice sheet though is much smaller, and there is the possibility that it might melt completely in the next 50-150 years.
There is also an even remoter possibility that the rate of growth in ground-water under the ice sheet may increase.
This could lead to an extremely large ice sheet sliding into the North Altlantic. This very remote possibility may then, in fact, cause a mini (localised to Europe) ice-age, as the change in Atlantic ocean salinity may effect the North sea current.
Luddites
John Hill is making the assumption that Carbon Tax "denialists" do not believe in Global Warming, that jump in logic is not valid. Many of us accept the science, its just that we do not see Global Warming as necessarily being a bad thing ?. Yes there will be many local disruptions, but on a world wide balance there will be a lot more land available for aggriculture. We are only hearing about localised adverse effects, has anybody done a Whole of Earth cost/benifit study ?. Change is what drives human progress, those who cling to the status quo are little better than Luddites.
Effects of 4C rise still speculative
Whilst I agree fully with the view that we need to stop increasing CO2 levels as soon as possible, I also believe that we will have to face the prospect of a 4C rise at least.
For at least the next decade, world output of CO2 emissions will still increase. There just isn't sufficient political will to stop that from happening.
Given that the warm periods between recent ice-ages have been warmer than this, without 70m rises in water levels, or the complete melting of the Antarctic ice sheet, I think some of the predictions being made in this article are alarmist. These sorts of predictions are not being made by the IPCC.
It is important for us to only make predictions that are evidence-based, and highlight the uncertainty, for example "sea levels shall rise by 2010 to between 0.5m but might be as high as 7.5m".
The effects of the Greenland ice-sheet melting, referred to is very speculative. If the rate at which it is melting continues to increase by 7% per year, as it is doing now, it will raise average sea levels by 51cm (2010) above the current expansion rate of 3.1mm/decade, ie 30cm by 2010, so we are only talking of 80cm - not 70m. In fact the NSF think that the rate of increase will level out to between 1-3% in which case it will only add another 20cm on top of the 30cm by 2010.
Weight of Opinion
85% of published climate scientists disagree with the denialist lay-people posting below. Why do people cling on to their non-science gut feels? It's not as if these climate scientists are driving around in Aston Martins purchased via their ill gotten extortions from gullible governments and do-gooders the world over. These people get paid poorly when compared to other disciplines. What is their motivation again to concoct a majority conspiracy?
We don't even believe our vaunted CSIRO anymore? We would rather read a Murdoch tabloid to source our science information. We even trust a patently hypocritical god-botherer like Tony Abbott on science matters?
A carbon tax, ETS or even direct action are conservative, economically rational responses to an extremely disruptive threat which has a very high probability of being real. Betting on the 15% outcome while delaying action because the likes of "Lord" Monckton and the Mad Monk argue over supposedly unsettled science is absurd and very dangerous.
Global sea temperatures
Methinks Mr Youles is dangling some very juicy bait here. Either that or it's a case of banging the same old drum can make you deaf.
And we should trust the future of the planet to your blaseness rather than heeding the warnings of almost all the world's cimate and related scientists exactly because...?
Global sea temperatures
Methinks Mr Youles is dangling some very juicy bait here. Either that or it's a case of banging the same old drum can make you deaf.
And we should trust the future of the planet to your blaseness rather than heeding the warnings of almost all the world's cimate and related scientists exactly because...?
Australia at plus 4°C: Not so hot
Some of these scientists need to go back to school and learn a little about the coefficient of thermal expansion. Sea level will only rise by the numbers that they are talking about is if the earths crust shrinks and the water has no where else to go. As for the ice melt it came from the oceans anyway. Try filling a glass with ice and fill to the brim with water and see if the glass overflows when the ice melts.
In response to Paul Rainbow
When there is a shortage of bananas, the price rises, demand falls, and the balance between consumers and suppliers is maintained.
As tobacco is a health risk, we tax it to discourage its use and to increase the health budget.
Why is a carbon tax any different? It uses fiscal policy to discourage burning CO2, and therefore, in relative terms make alternate power generation, including Thorium reactors more viable.
Most of the tax raised is given back as more $ to spend. We will, on average, spend that money less on things that have gone up, and more on things that have not. Simple economics. Why is it so hard to understand?
The rest of the tax will be spent on industry relief, and R&D on new technologies.
Cap and trade is similar. Permits are sold by the government in the same way as bonds. The price though is market driven.
A Thorium reactor may be the way to go, but the days of governments owning and building power generators is gone. In the next 10-20 years, we may have a power company lobbying a State and the Federal government to assist them to override NIMBY objections to the construction of a nuclear power plant. I hope that the plant isn't a conventional 1950's style light water reactor, similar to those at Fukushima.
The governmental role will only be to approve or disapprove the construction of such a plant. No State or Federal government will actually take responsibility for it.
Shakes head
It is not swings and roundabouts - the higher lattitude climates that may become more climatically suited to crop production are unlikely to have soils suited to such use, meaning that a significant reduction in overall arable land globally is the overwhlemingly most likely scenario.
There is a reason life 'thrives' in warmer climates - existing species get wiped out, which creates ecological niches for new species. This takes place over millions of years, not the microscopically small time horizons of humans. To somehow say this is a boon is ridiculous.
And as well as the massive reduced time scale of predicted warming over the Paleocene-Eocene Thermal Maximum, we have the minor issue of trying to feed 6-7 billion people while all this is taking place. Will the world support 1 billion people in a 4 degree increase scenario - probably. But there are 6 billion people who wouldn't be happy with this arrangement.
It's simple - CO2 is a greenhouse gas, burning fossil fuels increases atmospheric concentrations. The natural thermostat processes to regulate this have finite limits. Therefore, if we keep burning fossil fuels - it will got hotter. Anyone who pretends otherwise is just kidding themselves.