NASA's Jim Hansen on Greenland ice pack
Climate change: On the edge
Greenland ice cap breaking up at twice the rate it
was five years ago, says scientist Bush tried to gag
By Jim Hansen
Published: 17 February 2006
A satellite study of the Greenland ice cap shows that it is melting far
faster than scientists had feared - twice as much ice is going into the sea
as it was five years ago. The implications for rising sea levels - and
climate change - could be dramatic.
Yet, a few weeks ago, when I - a Nasa climate scientist
- tried to talk to the media about these issues following a lecture I had
given calling for prompt reductions in the emission of greenhouse gases, the
Nasa public affairs team - staffed by political appointees from the Bush
administration - tried to stop me doing so. I was not happy with that, and I
ignored the restrictions. The first line of Nasa's mission is to understand
and protect the planet.
This new satellite data is a remarkable advance. We are seeing for the first
time the detailed behaviour of the ice streams that are draining the
Greenland ice sheet.
They show that Greenland seems to be losing at least 200 cubic kilometres of
ice a year. It is different from even two years ago, when people still said
the ice sheet was in balance.
Hundreds of cubic kilometres sounds like a lot of ice.
But this is just the beginning. Once a sheet starts to disintegrate, it can
reach a tipping point beyond which break-up is explosively rapid. The issue
is how close we are getting to that tipping point. The summer of 2005 broke
all records for melting in Greenland. So we may be on the edge.
Our understanding of what is going on is very new.
Today's forecasts of sea-level rise use climate models of the ice sheets
that say they can only disintegrate over a thousand years or more. But we
can now see that the models are almost worthless. They treat the ice sheets
like a single block of ice that will slowly melt.
But what is happening is much more dynamic.
Once the ice starts to melt at the surface, it forms lakes that empty down
crevasses to the bottom of the ice. You get rivers of water underneath the
ice. And the ice slides towards the ocean.
Our Nasa scientists have measured this in Greenland. And once these ice
streams start moving, their influence stretches right to the interior of the
ice sheet.
Building an ice sheet takes a long time, because it is limited by snowfall.
But destroying it can be explosively rapid.
How fast can this go? Right now, I think our best measure is what happened
in the past. We know that, for instance, 14,000 years ago sea levels rose by
20m in 400 years - that is five metres in a century. This was towards the
end of the last ice age, so there was more ice around. But, on the other
hand, temperatures were not warming as fast as today.
How far can it go? The last time the world was three degrees warmer than
today - which is what we expect later this century - sea levels were 25m
higher. So that is what we can look forward to if we don't act soon.
None of the current climate and ice models predict this.
But I prefer the evidence from the Earth's history and my own eyes. I think
sea-level rise is going to be the big issue soon, more even than warming
itself.
It's hard to say what the world will be like if this happens. It would be
another planet. You could imagine great armadas of icebergs breaking off
Greenland and melting as they float south. And, of course, huge areas being
flooded.
How long have we got? We have to stabilise emissions of carbon dioxide
within a decade, or temperatures will warm by more than one degree. That
will be warmer than it has been for half a million years, and many things
could become unstoppable. If we are to stop that, we cannot wait for new
technologies like capturing emissions from burning coal. We have to act with
what we have. This decade, that means focusing on energy efficiency and
renewable sources of energy that do not burn carbon. We don't have much time
left.
Comments
The world according to Jim.
There is nothing but a few thousand individuals (does not the UCS have ~ 100,000 members?) presented as 'a consensus of scientists' but all these 'individuals' give is opinion. Scrutiny of that opinion is presented as 'unscrupulous activity'.
Perhaps life has until now been too 'easy' for 'climatologists'.
The 'thousands of scientists and Jim' are only a 'drop in the bucket' of the ~500 MILLION tertiary degree (or equivalent) holders alive in the word today, and there is NO 'closed shop' in this matter, the materials involved are common and the knowledge is near 'common' level.
The situation is that there is no valid reason as yet presented to even think a 'greenhouse effect' is present, let alone that 'emmisions' of 'combustion' are altering 'climate'. It has just been too easy obvioulsy for 'climatologists' to 'get by' on presenting 'opinion' to the MEDIA. Pictures of melting ice are just that, images of melting ice. Why should it be that the 'glacier' should even be considered to have a balance?
As to the supposed 'climate change' link, to quote from a link I have given often enough:-
["Many glacial advances and retreats have occurred during the last billion years of Earth history. These glaciations are not randomly distributed in time. Instead, they are concentrated into four time intervals."]
["During each of these intervals, many glacial advances and retreats occurred. For example, over 60 glacial advances and retreats have occurred during the last 2 million years."]
["If "ice age" is used to refer to long, generally cool, intervals during which glaciers advance and retreat, we are still in one today."]
***["Our modern climate represents a very short,]***
***[ warm period between glacial advances."] ***
The seas have never risen in a uniform manner, and have been in an overall 'rise' for thousands of years. So the seas will rise by '40 cm' (~15.5 inches) in 100 years, is 'beach erosion' by this process at all relevant? No it is not. You can document sea level alterations in a more direct manner by looking at now submerged 'permanent human infrastructure'. This is predominately in the Mediterranean region and covers the last 5000 years.
First, consider the extract from an outline of the 'greenhouse effect':-
-----
[" CO2 in the atmosphere traps heat (outgoing infrared radiation). (Incoming sun rays are in the ultraviolet spectrum.) Without this layer of insulation, the "natural greenhouse effect', temperatures on Earth would be about -17degree Celsius. Thus, increased CO2 in the inner atmosphere (or troposphere, ~6 miles up) is exaggerating the natural greenhouse effect and increasing heat trapped in the troposphere."]
-----
-: then realise that
(1) The first mistake in the 'greenhouse concepts' is that 'HEAT' (the measure of the average KINETIC ENERGY of the atoms molecules of the sample' cannot be trapped, it cannot escape to the Vacuum of space to begin with once it is generated.
This is WHY the 'quoted version' of the 'greenhouse effect' has mentioned that: - ["Over the past several decades the troposphere has actually swollen by several hundred feet due to the warming and thermal expansion of the air."]
-: as the PRESSURE (related to the average KINETIC VELOCITY of the molecules/atoms of the sample) is increasing. Realise that the only constraint OF the atmosphere is GRAVITY.
(2) This is NOT insulation, "Heat", measured on a scale as a 'temperature', is the average kinetic energy of the molecules/atoms of the sample, and is unable to leave the biosphere to open space. The KINETIC VELOCITY of the molecules/atoms comprising the atmosphere is the expression of the KINETIC ENERGY they possess. This can only leave the atmosphere if the MOLECULES/ATOMS actually LEAVE.
The mistake with 'greenhouse science' is to link with attempts to present PHOTONIC REEMITTENCE by these molecules as 'blackbody radiation' then infer a 'temperature' from the 'readings'. However, the energy reemitted as Secondary Photons after interaction of a molecule and incident Photon is infact the realisation of the energy involved in AND released by the interaction as NOT being 'converted to heat', that is increasing the kinetic velocity of the molecule.
At this point the 'greenhouse theory' is immediately **REVERSING** the known SCIENCE of the situation, and this WAS known in the THREE FAILED attempts in the 20th Century to have validated the 'greenhouse concepts'. It should have been very clear at least after the THIRD FAILURE. As such, satellites are NOT taking a temperature reading of the atmosphere OR the surface, these 'measurements' are of RADIATION and the Photons OF this radiation that are escaping the Photonic cascade, representing energy that was NOT converted to kinetic energy, and cannot be VALIDLY regarded as a providing a 'measure of temperature'.
Also note figure 1vs.jpg again in:- http://www.climateimc.org/?q=node/312
-: and note WHY only energy in the lower third of the UV Spectrum, and also the upper and lower Visible spectrum (consumed by Photosynthesis) becomes surface incident. Note also the H2O is constrained below its ice and condensation altitudes by GRAVITY.
There is a problem, it is just NOT involving any supposed 'greenhouse effect'.
See link http://www.climateimc.org/?q=node/312
Lastly, there are still some trying to infer, as has been 'tried on' in the recent past, to allude that perhaps I suffer from "Cognitive Dissonance" as I simply do not 'believe', and also raise points the 'few' find impossible to counter with their 'science'.
It seems that indoctrination of belief in a concept, as is tried in relation to 'greenhouse warming' concepts, produces irrational behaviors, with unreasonable aggression in those who consider the 'belief' to be threatened. But little real justification for their belief or any comprehension of the realities beneath the situations our society presents.
As the basis of the formation of Cognitive Dissonance in any population, the initial step is to produce 'experts', 'talking heads' whose 'fame' is more by constant mention than ability or deed. These 'experts' produce scenarios of 'danger, doom and woe' if their words are not heeded.
You see the style and platform of imposing nomenclature, names for 'processes' that are 'specialised', used within the 'special area' of knowledge known to the 'experts, in a manner of 'seeming' to be scientific', but are only covering contents of little validatable 'science'. That is why only the 'experts' are platformed to be the ONLY Ones to listen to. Such a label seen about is "Polar Amplification". The attempt is to try to produce an attitude of a 'closed shop' and only the OPINIONS of these few are platformed as 'relevant'. This returns to the 'history' trailing behind the 'greenhouse concepts', its failures within the arena of SCIENCE and motion into the arena of Politics.
Another example is the production of 'Anti Communist' sentiments, which where garnered in the 1950s USA, with the institutionalisation of processes to combat 'dangerous communism and its practitioners'. The internet is good at allowing such activity, hence the number of inconspicuously censored sites where 'unwanted' comment is removed, accompanied by ridicule of the author, as the censorship cannot be justified simply by quotation of the 'belief' system platformed.
In the end, it is that Oil is NOT only used for fuel, and apart from eating it, Humanity has become near totally reliant on 'fossil' derivatives for everything from hosiery to carpet, cloths to cars, and furniture to homes. Look for the word 'synthetic' and begin to realise.
The situation is that ALL the other products derived from fossil oils will STILL be needed, so the diffraction of fossil oils WILL continue, and so there WILL be fossil oil based fuel products, but maybe not in the same volume, which will be supplemented with bio-fuel oil volume and be combustible in present technology compression engine designs near immediately, often with little alteration to tehse engine designs.
Your's, Peter K. Anderson a.k.a. Hartlod(tm)
Member of the Public, Australia.
From the PC of Peter K Anderson
E-Mail: Hartlod@bigpond.com
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