There is ample evidence that the earth's climate has always changed, that there have been ice-ages and interglacial warm periods and sometimes dramatic shifts in temperature over relatively short periods. This is what I understand by 'climate change'.
I understand that the United Nations Framework Convention on Climate Change defines 'climate change' as that which is attributable directly or indirectly to human activity. I consider this definition to be wrong and subversive and I reject it.
Given that the earth's climate has changed in the past, it is reasonable to assume that climate will change in the future - whether or not we do anything about rising atmospheric carbon dioxide levels.
Because I have often stated that there will be climate change whether or not we do anything about the increasing atmospheric carbon dioxide levels, I have been accused of not caring, or suggesting we should not try and do something about carbon dioxide emissions.
Indeed Friends of the Earth misrepresent my position in their media release of last Thursday by stating that "Dr Jennifer Marohasy conceded that climate change is inevitable and we should adapt to what's coming but not reduce greenhouse gas emissions" ( http://www.scoop.co.nz/stories/WO0507/S00436.htm ).
I have never said that we should not try and reduce greenhouse gas emissions. I have always said that we should be concerned about increasing carbon dioxide levels. I have suggested investment in new technologies as a better option to Kyoto.
Friends of the Earth accurately quote me: "I actually think that it's good if we can get beyond this debate of whether increasing carbon dioxide levels are driving more extreme climate events. I think that we need to move beyond that and accept and recognise that whether or not we can reduce carbon dioxide levels, there will be climate change."
On this basis governments need to develop reactive contingency plans. I do not believe that climate change will necessarily be 'catastrophic' - but I do suggest we should prepare for more extreme weather events, as well as the possibility that it could be either drier or wetter in the future.
Furthermore, I suggest that trends in climate change can and should be evaluated using empirical data as well as computer models.
In summary, I am concerned about climate change and I have always been concerned about climate change.
I do acknowledge that carbon dioxide is one of several greenhouse gases. The empirical evidence, however, does not show a clear relationship between increasing atmospheric carbon dioxide levels and global temperatures. Global temperatures have increased, but only slightly (0.6C over 150 years) and have jumped about from year to year. In contrast the increase in carbon dioxide levels has been significant and linear. Other things are clearly affecting global temperature.
I consider Thursday's announcement of the new climate pact between the USA, Australia, South Korea, Japan, India and China to be great news (http://www.abc.net.au/news/newsitems/200507/s1425101.htm).
Here is a commitment focused on reducing carbon dioxide levels that has a chance of delivering something significant because it includes the emerging superpowers of India and China.
I am amazed that this deal is being critised on the basis that it may deliver very little, when the Bob Browns of the world have always acknowledged Kyoto will deliver very little but they have said it is at least a first step.
Well, why not then consider the 'Asia-Pacific Partnership on Clean Development and Climate' a second step?
Of course one should never count chickens before they've hatched but today's Australian newspaper (page 6 The Nation) quotes the Bureau of Met as saying that July temperatures seem to have set the nation on course for a possible warmest year on record.....
and all those high temps in the USA too
and not even an El Nino year ....
hmmmm....... it's all enough to make your head spin ....
Does IPA receive funding from ExxonMobil
Are they are specific issues to which any such funding is applied.
Loius: You now need to answer my question or admit that what you are saying is absolute rubbish. Until you do I am starting a permenant post on my blog "Loius Hissink writes scientific b-----t". It will remain until you answer the question or admit that you are wrong and stop deceiving less well informed people.
The question is "If there was no greenhouse effect the Earth would not be about 33 degrees warmer than if it did not have an atmosphere. Explain how this warming occurs without the action of the greenhouse effect"
As backgound information you might want to consult is this http://www-k12.atmos.washington.edu/k12/resources/mars_data-information/temperature_overview.html
It is a temperature overview of Mars. Mars has only has a thin atmosphere and no oceans. Its measured temperature range is "temperatures range from + 1° F, ( -17.2° C) to -178° F (-107° C). However, the temperature of the surface at the winter polar caps drop to -225° F, (-143° C)". It does receive less solar irradiation however, with the lack of a heat trapping atmosphere and oceans the range of daytime to nighttime temperatures is dramatic.
Do you need anything else to answer it?
I will also add to the post these questions that you have also failed to answer.
Biomarkers in oil
Measurements of heat flowing from the ground
This is from the article:
"Due to the low density of the Martian atmosphere, the temperature of the surface is controlled primarily by solar heating, and infrared cooling to the atmosphere and space, rather than heat exchange with the atmosphere. The lower few kilometers of the atmosphere during the day, and the lower tens to hundreds of meters during night, are in turn controlled by heat exchange with the surface, and by absorption of infrared radiation from the sun and surface and re radiation to the surface, space and rest of the atmosphere. For the same conditions, (wind speed, clear sky, etc.), the denser atmosphere of Earth near the surface exchanges more heat with the surface, than does the thinner Martian atmosphere. i.e, Earth's atmosphere has more influence on the surface temperature than does the Martian atmosphere. One might speculate what the diurnal temperature range of an object on the Martian surface might be if it had a thick atmosphere like Venus, (without its cloud cover), or an almost non existent atmosphere like our Moon which has only has a few molecules whizzing around like projectiles on ballistic trajectories."
But it doesn't drop to minus 18 degrees on clear nights does it? A warmed gas doesn't drop to abolute zero as soon as the warming source is removed.
If we had no greenhouse effect at all it might be a tad cold for most of us ....
Thanks Louis that's all we needed. You've just holed your argument...
Remember Jen you read it here !
"while CO2 does absorb energy"..... bye bye now !
P.S. The Sun, which is the Earth's only external form of heat, emits solar radiation mainly in the form of shortwave visible and ultraviolet (UV) energy. As this radiation travels toward the Earth, some is absorbed by the atmosphere and some is reflected by the clouds back into space. The remaining radiation travels unimpeded to the Earth and heats its surface. The Earth releases a lot of energy it has received from the Sun back to space. However, the Earth is much cooler than the Sun, so the energy re-emitted from the Earth's surface is much weaker, in the form of invisible longwave infrared (IR) radiation, sometimes called heat.
Greenhouse gases like water vapour, carbon dioxide, methane and nitrous oxide trap the infrared radiation released by the Earth's surface. The atmosphere acts like the glass in a greenhouse, allowing much of the shortwave solar radiation to travel through unimpeded, but trapping a lot of the longwave heat energy trying to escape back to space. This process makes the temperature rise in the atmosphere just as it does in the greenhouse. This is the Earth's natural greenhouse effect and keeps the Earth 33°C warmer on average than it would be without an atmosphere, at an average 15°C. In contrast, the moon, which has no atmosphere, has an average surface temperature of -18°C.
David Vader,
A natural greenhouse effect means a closed thermal system.
Greenhouses do what they do by stopping the circulation of air within the confines of the glass house. The earth is not so contrained.
While CO2 does absorb energy, which has never been denied, it does not retain that energy because it, as the rest of the atmosphere, is in thermal dis-equilibrium with space.
Your Greenhouse theory might have legs if you could show that energy is not being transferred to space, but somehow, and then magically, locked into the atmosphere.
It is not. Try sleeping in a desert during the middle of summer.
So Louis you are saying there is no such thing aa a natural "greenhouse" effect as termed by Arrhenius and predicted by Fourier.
And Jen if we agree that CO2 is a greenhouse gas, and without our atmosphere of greenhouse gases that the Earth might be a lot colder, would it not seem logical as a first premise that more CO2 may have "some" effect.
On the interesting issue of surface vs lower troposhere.
Nature 429, 55 - 58 (06 May 2004)
Contribution of stratospheric cooling to satellite-inferred tropospheric temperature trends
QIANG FU1, CELESTE M. JOHANSON1, STEPHEN G. WARREN1 & DIAN J. SEIDEL2
1 Department of Atmospheric Sciences, University of Washington, Seattle, Washington 98195, USA
2 NOAA Air Resources Laboratory, Silver Spring, Maryland 20910, USA
From 1979 to 2001, temperatures observed globally by the mid-tropospheric channel of the satellite-borne Microwave Sounding Unit (MSU channel 2), as well as the inferred temperatures in the lower troposphere, show only small warming trends of less than 0.1 K per decade (refs 1–3). Surface temperatures based on in situ observations however, exhibit a larger warming of 0.17 K per decade (refs 4, 5), and global climate models forced by combined anthropogenic and natural factors project an increase in tropospheric temperatures that is somewhat larger than the surface temperature increase. Here we show that trends in MSU channel 2 temperatures are weak because the instrument partly records stratospheric temperatures whose large cooling trend offsets the contributions of tropospheric warming. We quantify the stratospheric contribution to MSU channel 2 temperatures using MSU channel 4, which records only stratospheric temperatures. The resulting trend of reconstructed tropospheric temperatures from satellite data is physically consistent with the observed surface temperature trend. For the tropics, the tropospheric warming is 1.6 times the surface warming, as expected for a moist adiabatic lapse rate.
Satellites indicate a cooling in the lower stratosphere. This result is consistent with weather balloon measurements. Cooling in the lower stratosphere has long been regarded as a strong indicator of greenhouse-induced climate change.
Measurements in all of the major ocean basins of the world show that the warming of the latter half of the last century has penetrated to a depth of 1000 metres. Rates of world-wide glacial retreat and the thinning of Arctic sea-ice and Artic warming are further evidence of warming. Greenland you say – well as previously posted – ice is moving there too…
All of these together are a BODY of evidence. But you guys like to cherry pick odd exceptions and then argue back from the specific to the general ignoring the greater body of evidence.
George Burns smoked till he was 100 so smoking must be OK then ?
So we have something global – you’ll have to make a strong argument for orbital solar change to give a coherent alternative explanation. So what’s a good explanation then? You’re the one saying “evidence-based” environmentalism. What's this selective evidence when it suits your argument?
Another topic- let’s cherry-pick that "runoff onto the Reef is 5x pre-European" – based on this evidence I say we close down the beef and sugar industry – OK with you ?
Louis - Normal is where the rate of carbon going into the atmosphere is equaled more or less to that being taken out by plants and the ocean. At the moment it is clearly out of balance as the instruments are telling us. Are you going to argue with them now?
OK here is where I will hound you for an answer and everyone reading this blog will realise that you really do not know anything about how the atmosphere works if you pike answering this one.
You have said "Er there is no such thing as a greenhouse gas.". So explain to all the readers here why the Earth is 33 degrees warmer because of the atmosphere.
Er there is no such thing as a greenhouse gas.
Greenhouse means a closed energy circuit - the earth is an open circuit.
Analogy disproved.
David,
I wrote in the main blog piece that C02 is a greenhouse gas.
I also wrote that atmospheric C02 levels are increasing.
However, last time I tried to understand whether the troposphere was warming more or less than the earth's surface - I found several different answers. What is the latest?
Ender,
what is normal?