I guess climatic changes are evident and eminent. During the course of earth's geologic history, both the ice ages and warm epochs are well documented. The matter of fact is that how far the human's have affected the climatic variables. Few undeniable facts our carbon foot print is large, much larger than anytime humans had in past several thousand years. GHG concentration's are going up, is an undeniable fact. The question is will this increase in CO2 and other GHG will create a situation that carbonate dissolution will start, ozone depletion will take place etc, are still matter where there is no consensus.
I'm always a little confused about the difference between climate change and global warming. I hope I'm not the only one with this problem, so maybe it would be good if someone explains this briefly before we get started, just so that the contributions are actually all about the same issue.
Climate change = wide scale observable changes in the earth's climate.
Global warming = increase in earth's surface temperature.
Kenneth on this forum has given various detailed explainations. I would suggest refer to his writings, which are both interesting and informative.
I guess climatic changes are evident and eminent. During the course of earth's geologic history, both the ice ages and warm epochs are well documented. The matter of fact is that how far the human's have affected the climatic variables. Few undeniable facts our carbon foot print is large, much larger than anytime humans had in past several thousand years. GHG concentration's are going up, is an undeniable fact. The question is will this increase in CO2 and other GHG will create a situation that carbonate dissolution will start, ozone depletion will take place etc, are still matter where there is no consensus.
There is no doubt on Climate Change, but I can suggest that talk "http://www.ted.com/talks/bjorn_lomborg_sets_global_priorities.html" as an alternative perspective for solutions. I can't say that I can completely agree this perpective but it also seems true for a modern world.
Regards
The question is rather confusing; there is no doubt that climate change is happening, the argument lies in whether it is part of a natural cycle or whether it is man-made? Personally, nowadays, I feel that the question is moot; whether natural or man-made, the impact is likely to be great (both economically and socially) and so all our efforts should be expounded in mitigating as much of it as we can. It is ethically wrong to use the argument that climate change is part of a natural process to block governments from taking action to limit its effects. Climate change will probably cause countless deaths worldwide (whether due to man-made effects or natural fluctuations) - who would want that on their conscience?
@John, sad to mention, but some people still do not believe in climate change. The man-made component is an even bigger argument.
Kenneth, your comment brings up a couple of questions.
Why do you think Michael doesn't use his real name and personal information? What is the source of your information? And what exactly do refer by "climate change"? I suppose you don't simply mean temperature increase.
Michael, I have to say I don't like the undertone of your question and explanation.
Your question suggests that a "reasonably intelligent scientist" who "does not believe in climate change" is a rare thing. In other words, a scientist who does not believe in climate change generally is not reasonably intelligent. Also, by asking them to step forward to explain themself, you're putting them on the spot and disvalue their answer before you even hear it.
I would be very interested in listening (or reading, for that matter) to their points of view on the issue, but I'm afraid the way you phrased your question no one of them will step up. Maybe that's also the reason why your question has been voted down three times so far.
Hello, my name is Michael Mannen, as indicated at the upper left hand corner of my comment. All of my credentials are outlines on this site; with the exception of a few unpublished works that may be included for future viewing.
@Elliott, this is a neutral setting; no opinions, just science. Believing in climate change is irrelevant to it happening. Glad you cited a source.
@Toni, A scientist that ignores data is no scientist at all; the undertone is explicit.
All that do not believe in climate change/anthropogenic causation, leave your politics at the keyboard, and cite your sources. No harassment will be made. I will not address any argument against climate change without data. Period. Anybody that offers any argument without data, is a not considered to be an intelligent scientist in this discussion.
What anyone "believe" should be irrelevant? Hopefully the AGW hypothesis according to IPCC - is not a religion? Are there valid scientific questions that produce evidence against the certainties so often claimed in the climate change debate? Yes, there are. How certain can we be on the assumed antropogenic impact on climate? IMO and politics set aside, the answer is that we really don´t know the size of the impact for the moment.
There are plenty of serious papers that discuss/questions everything from a tiny detail to the major conclusions drawn in the IPCC reports.
(Be also aware that "climate change" have different meaning:
Article 1, UNFCCC:
"Climate change" means a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.
IPCC Working Group I (AR4, 2007)[6], Summary for Policymakers
"Climate change in IPCC usage refers to any change in climate over time, whether due to natural variability or as a result of human activity.
So which of these dominating definitions are you referring to?)
Here is ONE example questioning the attribution to an antropogenic impact:
Beenstock, M., Reingewertz, Y., and Paldor, N.: Polynomial cointegration tests of anthropogenic impact on global warming, Earth Syst. Dynam., 3, 173-188, doi:10.5194/esd-3-173-2012, 2012.
From the paper: "....This means, however, that as with all hypotheses, our rejection of AGW is not absolute; it might be a false positive, and we cannot rule out the possibility that recent global warming has an anthropogenic footprint. However, this possibility is very small, and is not statistically significant at conventional levels".
You will NOT read this kind of paper in the IPCC-reports and that is because that is not the mission of the IPCC. Their mission is to collect evidence that support the AGW hypothesis. (Don´t take it from me, read their program). This will of course introduce bias which is fine as long as you are aware of that. Most are not.
My opinion - (if that matter) - is very close to Judith Currys, probably one of the most merited climate scientists around. She often claim that uncertainties are ignored or downgraded. Uncertainties, that in any other research field would make it impossible to draw any firm conclusions, let alone base any world wide strategies on them.
So to me the AGW hypothesis should not be left alone or embraced beyond criticism. It doesn´t matter if one "believes" or not. The hypothesis should be constantly questioned. That can only strenghten it - if its true and then give us a more solid ground for conclusions. The null-hypothesis is STILL natural variations and the core of the problem is that we don´t have knowledge enough to understand, let alone predict, these natural variations. If we had, the 17 year hiatus would not be a surprise and the "missing heat" would have been found. But it hasn´t: not in the atmosphere nor in the oceans (yes the oceans are warming but not near the rate expected, see my "question" on that).
So, maybe I make some people disappointed? I do "believe" in Climate Change and an anthropogenic impact, but at the same time I am not convinced, given the whole picture and the WHOLE spectrum of evidence (not just IPCC), that we (the humanity) are facing an immediate threat. There are far more urgent needs that deserve attention. During my miltary service I learned to use my ammunition on enemies that were in sight and posed a real threat. I never spent one bullet on a "maybe" sniper hiding in the bushes. Who knows more about survival strategies than the military?
@Kenneth; I have returned and its time to silence the critics.
*Kenneth, on planet earth a 1 degree temperature change is significant; change of 1 degree in Southern States could extinction for some species.
*Providing data without a link will not be addressed concerning your temperature remarks.
*Temperatures across the globe has been increasing since the 1960's; From the national climate data center
http://www.ncdc.noaa.gov/img/climate/globalwarming/ar4-fig-3-6.gif
*Small changes in temperatures have major impacts on ecosystems.
From NASA:
http://earthobservatory.nasa.gov/Features/WorldOfChange/decadaltemp.php
**Takes the earth about 5000 years to warm 5 degrees; life cannot evolve quickly enough to respond.
**5 degree change in temperature changed the last ice age....
Temperature on earth is changing, and it is man made.
"Takes the earth about 5000 years to warm 5 degrees; life cannot evolve quickly enough to respond. 5 degree change in temperature changed the last ice age...."
Not all facts are correct. You quoted NASA, but have you read The Two Mile Time Machine by Richard B Alley?
According to the Greenland ice cores and sediment records from Venezuela, the average temperature of the Earth increased naturally by 15 degrees immediately following a gradual and then steep decline in average temperatures. This 15 degree jump occurred in less than a decade and probably much quicker.
It is true that nations have risen and fallen on just 1 degree of average temperature change, and it is true that species find it difficult to adjust, but it is also true that nature can deal much more change than a single degree and in a very short time. Just look at how many species perished 11,500 years ago.
Climate Change is very real. It has been observed in the paleoclimatological records around the entire planet. Natural cooling and thawing cycles have occurred repeatedly and to both extremes in a very short time. The fact that we are now experiencing a very large increase in CO2 while experiencing a pause, or even a decline, in global temperatures, clearly shows that anthropogenic climate forcing is very weak, it it exists at all.
I understand Michael's tone, he is young. But has scientific sprit and he wants to know if it is proved or not.
Just to illustrate:
https://www.youtube.com/watch?v=uA8KH6G_0hc
I am not expert, but some experts I know say that global warming is not proved, even that a mini-glaciation has more probabilities to occur. And climate changes, of course. It is a chaotic system, isn't it?.
Cheers.
@David, the earth goes through cycles that affect temperature, sure. However, this does not negate the impact of anthropogenic activity on climate change.
Attached is Alley's testimony before congress concerning the tissue; he points for controlling carbon output maybe useful for global warming.
The question is what is causing the abrupt climate change
http://www7.nationalacademies.org/ocga/testimony/Abrupt_Climate_Change.asp
Michael - it is not my view that human impact on weather and climate is zero. Many factors impact our weather. The question is to what degree humans are responsible and to what degree the Sun is responsible. We should also consider the effects of volcanoes, hurricanes, cows, trees, sequestered carbons, and numerous other factors contributing to the Earth's weather. In the end, the Sun is the most dominant factor; especially considering its shear size.
As for Alley's testimony that controlling carbon output can be useful for controlling global warming, it is a non-issue. Carbon dioxide output is spiraling out of control and yet the planet is not warming. In his testimony he, and other scientists, failed to explain the mechanics for why the planet is not warming in spite of a three fold increase in total CO2 in our atmosphere.
We are still talking about science, right? If CO2 is predicted to singularly increase the temperature of the planet, and a threefold increase fails to increase the planetary temperature for the past 17 years, doesn't that falsify the argument?
Also, since many respectable scientists have predicted a cooling of the planet due to a decrease in solar activity, and the planet has been observed to both stop warming and also to begin cooling, doesn't that support the hypothesis of the Sun controlling the Earth's climate?
From all the evidence I have seen, the human impact is lost in the noise of the Sun's influence. It may very well be that if the Sun had a steady output then the CO2 could be enough to make a measurable difference in the Earth's climate. But the Sun turns out to be quite dynamic and its influence completely saturates the effects of human existence on the surface of the Earth. Let's turn our attention to other matters that really make a difference in the world.
Small changes in climate temperature have profound consequences for global ecology. When the temperature in my house changes by .5 degrees F it is not a big deal. But for global survival of many species this becomes a big deal. Small changes in cyclic trajectories of climate for the earth can cause change that is a big deal; what is driving the underlying cycle is not relevant to human solutions for anthropogenic climate change.
David, the noise you are referring to is like a virtual particle; it is non-existent.
Meaningful questions on this topic:
*Is globally temperature getting warmer based on scales useful to climatologist and relative to global survival of species?
Data indicates yes; read previous posts.
*Do human activities contribute this change in climate?
Residual increases in atmospheric reservoir of carbon can be explained by increase flux of fossil fuel combustion due to industrial uses.
As I have writen and documented and discovered the mechanisms driving climate variability are of solar origin
https://www.researchgate.net/profile/Dimis_Poulos
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