Any comparison of temperatures needs to consider that climate scientists use anomalies and not "average" temperature. If stations are added or subtracted, these stations contribute by comparisons of the temperature change at that particular station over overtime. Using this approach much reduces the importance of the number of stations and reduces potential biases. Statistical studies show that the number of stations, even after some have been reduced, are enough for statistical overkill. The one exception is the poles, where warming more that twice that in the temperature zone. In general there is good agreement amongst international temperature records. However, the UK HadCrut database has worse coverage of the poles and therefore underestimates recent global warming.

For comparison of warming in countries or states, the number of dailly records is useful. For example, in the US, record highs outnumber record lows by something like 4:1 since the year 2000. This disparity in local record temperatures favoring record highs has increased markedly each decade over the past 40 years but especially in the last 20 years.

My first guess would be: profit.

Without debating the role of human beings on climate change, it is expensive to adjust our infrastructures to climate change.

Assuming that we are responsible for it is even worse, as a bunch of countries make huge amount of money destroying the planet :)

Profit, or more accurately: short-sighted greed, yes .. but I believe not the whole story:

Humantiy will simply not agree on a status quo.

- most have by now acknowledged climate change - but then again there are those who deny it.

I am sure that if you got all specialists on climate change on a table to get an agreement on a status quo for the scientific community, they could discuss a year and still not agree on a common opinion.

Would be interesting though - not like a congress where everyone presents his ideas, and either tolerates, admires or ignores other ideas, but actually get them to agree on a message to be conveyed to all politicians and journalists worldwide.

And then there would be the next very difficult step: convey this uniform set of ideas to all the politicians and journalists worldwide.

And then make them agree ....

nope, I just don't see this happening, sadly.

Hi Joy,

If they are really interested, then the book "Why we disagree about climate change" by Mike Hulme is a really good synthesis.

I recently had a chat with someone about the best solution to climate change which turned into a bit of a debate. They wanted to reduce emissions by pricing carbon but I preferred alternative renewable energy options. I think it's because we had different views on why climate change is happening beyond just CO2 emissions. For example they thought it was a failure in our economic system (the market fails to regulate pollution i.e. externalities), whereas I thought it was more a moral issue of looking after the environment. I guess climate change encompasses so many issues that a solution to one doesn't necessarily solve the others, and so no one can agree which is best.

And that's not even considering people who take issue with the science in the first place :)

I fully agree with you, Norma. As regard the academic community, I never found out about a scientist who had changed the camp as a result of new findings or re-evaluation of the old results and theories.

@ Jamie: thanks for the interesting answer. I will definitely read the book, heard about it but so far never had the time ... very interesting I think.

And yes, the reasons for climate change ... I also had some very interesting discussion on that - most interesting with people from different fields - economists, philosophers, and psychologists usually come up with the most diverse ideas. For example an economist once explained to me that we have to have people starving and rich first world countries producing lots of CO2 so that the markets won't collapse, which he again explained like this: "because not everyone deserves a mercedes benz" ... even after about 10 years, have not understood as to what exactly he meant with that

Very interesting arguments. But how would you explain the recurrent heating and cooling of the earth in Geologic Past, several ages of glaciation and then heating of atmosphere. High CO2 in preserved cores 1500 ppmv. All that without human interventions. I am not negating climate change but how much of it can be reduced and if humans reduce their carbon footprint will it cease?

A very unpopular answer, but one I have been working on for the past

13 years and 9 months is that the Earth grows and expands in uneven

steps or pulses. The result of a single pulse or step increase in the radius,

and thus the surface area of the Earth, is a decrease in the thickness, or depth of the

atmosphere, thus a decrease in the temperature and pressure of the atmosphere

at all elevations above sea level, and a change in the Lapse Rate, which is the rate

that the temperature and pressure decreases with increasing altitude.

In addition, the increase in the planets surface area, suddenly lowers sea level elevation, thus instantaneously changing the elevation of all of the continents by effectively raising them to a higher atmospheric level above sea level, and thus

lowering the temperature at all elevations globally. This leads to a temporary condition where glaciation runs rampant for a few thousand years until the

continents slowly lower themselves, and the sea floor gradually raises itself,

and the Earth releases more gasses until a new equilibrium of higher temperatures

can re-establish itself, and melt the glaciers from the continents, and then from the

Mountain valleys, and then from the higher latitudes, raises sea levels. and thus

raises the atmosphere at all elevations relative to the land, and makes all elevations warmer.

The change in CO2 amount would simply be a byproduct of this process,

where the total amount of vegetation, and the total reef production would

vary widely with changes in local and global temperatures. In contrast, a sudden

drop in ocean levels means instantaneous climate changes that kill reefs,

if the drop in elevation is sufficient enough, and change the locations where

forests and tropical vegetation is possible.

In natural settings, the change in CO2 concentration is a more gradual

process in both directions whether it is being released, or being

naturally sequestered by reefs and vegetation.

What is not natural is the current rate and the current rate of increase in

the rate of re-release of carbon from sequestration that took hundreds of

millions of years to sequester, and 300 years to release since around 1700,

until the present. The trend continues.

The planet will naturally get warmer as sea levels rise, thus lowering the

land compared to the water and the level of the atmosphere above the water.

However what may be un-natural will be the human intervention in nature's

normal process of allowing vegetation to run rampant to sequester the

excess carbon.

You know we are going to favor crop lands, and lands for buildings and roads, and

asphalt, and concrete rather than allow the land to naturally form forests, to

utilize the rising availability of CO2.

If we refused to use airplanes to travel quickly, and we refused to buy

automobiles with fossil fuel engines, and we refused to purchase food from

half way around the Earth, the producers would adapt. But we all know this

is not going to happen. We will enjoy our conveniences until the very

last dieing breath........our own.

I like your argument Clark.

There is no agreed-upon solution because:

1- There is no agreed-upon cause of the climate change

2- There is no agreed-upon agreement of the degree of the climate change

3- There is no agreed-upon definition of the climate change/climate variability/greenhouse effect/ ...

When we agree about these three points, we will agree about some solutions for it.

Mohammed I think you will agree that this is agreed that climate change is hapenning. I fully endorse your argument that causes are several and are often synergetic and most of them are known. How much they affect climate individually or in combination is a subject of debate and disagreement. But certainly this cannot be a reason to neglect the climate change issue. I have done some data collection of temperature in Kuwait since 1960s trends are not clearly suggesting any systematic warming. Similarly have some measurements at sea for temperature, salanity, pH and other phnysico-chemical parameters for past 8 years. Only evident trend is a sharp drop in pH. This drop cannot be due to CO2 assimilation and sequestration alone. I think in case of GUlf the Nox and SOx play an important role in acidification along with CO2.

Much more systematic research is required to identify the causes and took for solutions.

Dr. Saifuddin

What you said confirms that the problem exists, and there is no agreement neither for its cause nor for its solution.

Many thanks for your feedback..

We do know that what man changes has not had a habit of being beneficial for

the environment as a whole, though it has been beneficial for mans comfort

and convenience.

I suspect that we do not need to make astounding changes to limit our impact

on the environment, just intelligent changes.

Heating, cooling, and transportation can all be accomplished by electricity, but we need to get electricity from sources other than coal, natural gas, and oil.

Solar, Wind, Tidal, Geothermal, and Nuclear can all produce electricity, and

with a much lower overall impact on the environment.

Dear Michael,

I agree with you - except for one point: Nuclear Power Plants.

Nuclear Power Plants are not "green energy" at all, neither is it cheap in any way! - this myth has been held up for decades, but is thouroughly untrue, because if you add the CO2 and costs for

- the building of a powerplant

- the correct maintainance of a power plant

- the mining and transport of the radioactive matieral

- safe storage of nuclear waste

there is nothing green left about it.

to make a powerplant cost-neutral (the moment it will actually produce energy after all these investments) is after 20 years, because building a safe plant has that much cost - which is the moment that it should get a new coating. If you summarize the real costs (that have in terms of CO2 emissions been highly disregarded and in terms of costs mostly covered by tax money i.e. governments), natural gas/oil is about as green.

additional there are more than enough risks available. And, as is known, is that

- nuclear waste is dropped into the deep sea (and who knows when or where it will emerge again)

- the mining is partly done by children ( a way to make things cheaper of course)

- the reason that we still maintain this nightmare is, as I believe, the strong lobby. The nuclear lobby is, as far as I know, closely related to the weapon lobby - what a way of recycling :(

Best regards,

Norma

The question is not of science, I think, rather the political will to address the issue. If you follow IPCC and UNFCCC and numerous similar reports, adaptation and mitigation measures (main body of mitigation and solution measures) have been well studied. However there is no firm and agreed upon GHGs reduction time table on part of Annex I countries who have been recognized in Kyoto protocol as historically responsible for increased GHGs and thus found obligated to mitigate the negative impacts of climate change.

Joy

The question is on the magnitude of the change and the pace it will have in the near future. The urgency of adaption or mitigation has to do with this rate of change. when you read the IPCC-report, for free on the web, you will notice that the uncertainty in the change in temperature and sea-level in this century are large; a situation politicians do not particularly like. Also, the change is not in the near future, meaning a sitting term, so not an election issue

Check out this visualization of climate change over the next 100 years.

http://www.upworthy.com/the-future-of-the-earth-s-next-100-years-visualized

You are welcome, Djamel!

Joy

Nice movie, but I trust the very recent IPCC report more. Summary:

http://www.climatechange2013.org/images/uploads/WGI_AR5_SPM_brochure.pdf

Better even is the technical summary also free on the web

Mitigation of GHG is the effective way to deal with climate change . But this has proved to be difficult and costly . Nuclear had its problems even now . Although solar is progressing but it can not replace but a modest fraction of required demand for energy . Wind is doing well in many developed countries . So it is going to take sometime to have viable alternatives to hydrocarbons .

There is an excellent dissertation thesis by Friman (2013) on international climate politics that addresses the issue of assessing historical responsibility – one of many central aspects of policy agreements on climate change:

http://liu.diva-portal.org/smash/record.jsf;jsessionid=b76c8e6223674b89c34477ffe72b?searchId=1&pid=diva2:583947

I agree with you, Djamel. We all must be stewards of the earth.

Very appropriate remark from Djamil which encourages not only preservation of nature and plantations to offset climate change but it values the virtue of work .

i agree with Mr Djamel

and in fact, the our uncontrolled intervention on environment that change climate, and nobody wants assume his responsibility .

The reason there is no agreed upon solution is that no practical solution exists. The world population is growing. The developing world is developing. Everyone needs energy. Energy makes the world work. Energy use in the 21st century will increase several-fold. The financial, technical and social difficulties in quickly and severely reducing use of fossil fuels have been greatly underestimated by visionaries. There is no way to make it through this century without continued use of fossil fuels. Hopefully, we can gradually increase energy efficiency, introduce more renewables, and maybe find a way to increase nuclear power safely. However, even James Hansen, a leading spokesman for climate alarmism, says relying on wind and solar energy for rapid elimination of fossil fuels is like "believing in the tooth fairy". Furthermore, not all aspects of climate change are bad. I think the world climate today is more comfortable than it was in 1850.

The question which has not been seriously considered is whether climate change is a natural phenomenon, or is a man-made phenomenon, or a mixture of both. I am aware that the IPCC has purported to have examined this question - and decided strongly in favor of the man-made cause - but their work is, frankly, shoddy, and has a pre-existing bias in favor of the man-made cause. After all, what possible justification for its continued existence could the IPCC have if it decided that climate change was a natural phenomenon?

A fundamental element of the belief in man-made climate change is that carbon dioxide, once released into the atmosphere, stays there for hundreds of years. The laws of physics say that this is impossible:

1. The atmosphere currently contains about 800 gigatons (Gt) of carbon in the form of carbon dioxide, while the oceans contain 38,000 Gt, or about 50 times as much as the atmosphere. (Google the phrase 'The oceans as a CO2 reservoir' for the reference on this.) Moreover, since the volume of the oceans is much less than that of the atmosphere, the concentration of CO2 in the oceans, i.e. the amount per unit volume, is about 120 times that of the atmosphere. If anybody wants the calculation for this, I will gladly supply it.

2. In passing, the idea of ocean acidification is absurd. The oceans are comfortably alkaline with 120 times the CO2 concentration of the atmosphere. If the amount of atmospheric CO2 were doubled, it would change the oceanic concentration by less than 1% - and this is supposed to flip the oceans into acidity?

3. Henry's Law, first published in 1803, tells us that if we have a water/air interface with a concentration x of a gas in solution in the water and a concentration y in the air, then if an additional amount of that gas is introduced into the air, a fraction x will end up in solution in the water, leaving only a fraction y in the air. Therefore, if CO2 is introduced into the atmosphere, 120 parts of it will end up in solution in the oceans and only one part will remain in the atmosphere.

4. The time taken for CO2 absorption at the ocean/air interface depends on the oceanic/air ratio, and at a ratio of 120:1 is very fast indeed.

5. If one considers, for example, a coal-fired power station in the middle of a continental land mass, the CO2 it emits must obviously be brought into contact with the ocean surface for it to be absorbed. This requires both horizontal and vertical mixing.

6. Horizontal mixing, i.e. spreading the CO2 across the planet, will occur in a matter of a few weeks as a result of the general west-to-east wind motion. Vertical mixing, i.e. bringing CO2 at all levels of the atmosphere into contact with the ocean, will also occur in much the same time frame since atmospheric convection creates a near-continual vertical mixing process. Consequently, 99% or more of the CO2 from our power station will be absorbed in the ocean probably within less than a year.

7. The carrying capacity of the oceans for CO2 is enormous. The current 38,000 Gt could easily be doubled with little or no effect on oceanic chemistry or acidity. If all the oil, gas and coal in the world were burnt, it would produce less than half this amount.

8. Since CO2 does not remain in the atmosphere, it cannot be the cause of climate change. I will leave to others to determine the cause for the latter, but suggest that the theory of a CO2-induced greenhouse effect is completely fallacious.

The answer to our climate catastrophe is mitigation measures towards GHGs particularly CO2 but nations try to avoid the cost implications of carbon depent economies and regressive impacts approaches.

What "catastrophe"? I looked for it but I cannot find it.

Roger Graves: The oceans will not become acidic ( pH < 7) but there is already strong evidence in the scientific literature of adverse effects of lowered pH on moluscs and corals. some of this is a direct effect of lower pH on ability of these animals to produce calcified structures. There is also strong evidence showing that the decrease in pH already observed and expected in the next 50 years increases the solubility of toxic metals such as Se and Cd. Thus, dissolving of CO2 from fossil fuels into oceans is already having significant adverse effects on sea life. This is ongoing and published research from top scientists, much of it funded by the National Science Foundation (US).

There may well be local pH changes in the oceans. I do not dispute this. What I do dispute is that these changes are caused by carbon dioxide concentrations in the atmosphere. If the oceans already have a CO2 concentration 120 times higher than that of the atmosphere, and yet are firmly alkaline, then it is difficult to see how any very minor changes in the oceanic concentration resulting from atmospheric changes can have any significant effect on oceanic pH.

Oceanic pH value is almost certainly controlled and buffered by the very large numbers of sodium ions, present in sea water as NaCl. The concentration of NaCl in sea water is orders of magnitude higher than the CO2 concentration. If indeed there are verifiable, long-term changes in oceanic pH, I suggest we should be looking for the real reasons for this, rather than simply assuming it to be due to minor changes in CO2 levels.

Scientists are rather precisely measuring the effect on ocean pH due to the burning of fossil fuels. You also need to consider that most of the pH decline is in the upper 100 m, where most sea life exists. Transport of water, CO2, O2 etc to the deep ocean is slow. I did a Google Scholar search on "ocean acidification and fossil fuels" and came of with 21,000+ hits. The top cited ones include articles in Nature, Science, Proceedings of the National Academy of Sciences (USA). Some of papers deal with adverse effects of ocean acidification that have already been observed. Studies and grant proposals that I have read include pH treatments (in lab experiments) that include pre-inductrial levels, current levels and projected levels of ocean pH at the end of the current century given projections of fossil fuel use. Of course marine biologists and oceanographers understand the sea's buffering capacity. However, it turns out reductions of pHiof a few tenths of pH units, which equals and increase in H+ ions on the order of 20-40% are having bad effects of corals and molluscs. This sensitivity is somewhat surprising but is now well-unnderstood. NaCL concentrations are largely irrelevant and of course, water can hold high concentrations of CO2/HCO3-/CO3-3. If you read even a few of the articles in Google Scholar, you will have some understanding of ocean acidification. Note that chemists and other scientists use the term "acidification" to mean a reduction in pH, and the reduction does not necessarily need to take a solution below pH = 7.

Roger

You call the IPCC report "frankly, shoddy":

point out where that is the case in the very thorough report of WG1: I dare you to show where it is "shoddy". Point it out! Your personal opinion you can vent in blogs. This here is a scientific forum:

http://www.ipcc.ch/report/ar5/wg1/#.UrSjqC01jIU

I guess we should abstain from making such remarks as report is shoody. I am sure many of us have not read these deligently and back to back.

Roger

In my angriness on your impropriate remark on IPCC I forgot to tell you that your ideas are not shoddy but utterly wrong: CO2 is taken up by the upper layer of the ocean.

Go and read the IPCC report chapter 6, written by a selection of experts in this subject:

http://www.climatechange2013.org/images/uploads/WGIAR5_WGI-12Doc2b_FinalDraft_Chapter06.pdf

I do not deny that CO2 is taken up by the upper layers of the oceans. I simply question whether it has a significant effect on oceanic pH values.

If I were to run a research project on this subject (and I have run many research projects), I would ask the following questions as a precursor to any further work:

1. What is the present concentration of CO2 in the upper layers of the ocean at this time, and how does it compare with CO2 concentrations in the recent past? We have a good picture of CO2 concentrations forty years ago from the GEOSECS program, but I have been unable to discover any detailed CO2 mapping since then.

Incidentally, if atmospheric CO2 absorption has caused elevated CO2 levels in the upper layers of the ocean, this should be evident on a vertical profile of CO2 concentration. The GEOSECS profiles show no evidence of this whatsoever, which would seem to indicate that take-up of atmospheric CO2 did not have a significant effect on oceanic CO2 levels forty years ago.

2. What is the effect of exposing seawater to increased CO2 levels? How does its pH value react? A simple way of doing this would be to subject seawater to a laboratory test by measuring its pH value while gradually increasing the CO2 level in the atmosphere above it to, say, 450 ppm, then 500 ppm, and so on. Again, I can find no record of anyone having done this. If you do know of any such experiments, I would be grateful if you would let me know.

I have come across a report of the injection of liquid CO2 into seawater at several hundred metres depth, but this was an experiment designed to test the feasibility of carbon sequestration in the oceans, and falls outside the parameters for the tests I have suggested above.

3. Is there past evidence of harm to the marine environment caused by elevated atmospheric CO2 levels? Since there is a significant body of knowledge which suggests that atmospheric CO2 levels were in the 1000-2000 ppm region in the not-to-distant geologic past, say about 40 million years ago, which also corresponds to the great period of ocean reef building, does this not at least suggest that fears about harm to coral reefs from atmospheric levels of 450 ppm are groundless?

Roger

Did you read the chapter and section of the IPCC report on the CO2 cycle? Apparently not

Roger: Just read seveal of the articles that you can find from a Google Scholar search under Ocean acidification and fossil fuels. As I mentioned, I received 20,000 hits-- at least hundreds of these articles are relevant to your questions. One issue is that the current increase in atmospheric CO2 is about 100X faster than the prehistoric increases. This allowed for more buffering action and transport to deeper waters when that changes were over millenia, rather than decades.

Dear All, I agree with Roger on one aspect that the lowering on pH on local scales may not only be attributed to oceanic sequestration of CO2. I have added a dataset on this. Please have a look this is showing a pH drop of over 0.2 - 0.3 units in past 7 years, i believe it is a synergetic effect of CO2, NOx, SOx. just a throught.

On an ocean wide basis, the pH has dropped about 0.1 units since preindustrial times. Given rates of fossil fuel consumption, a drop of 0.2 is expect by 2050 and 0.35 by 2100. A slow rate of CO2 increase in the atmosphere allows the acid to be neutralized by CaCO3 introduced into oceans by normal weathering processes. Currently, acidification is about 10X higher than during the Paleocene-Ecocene mass extinction event when CO2 increased in the atmosphere and the earth's temperature increased by 5-6 oC. Acidification is widespread in the world's oceans but is not uniform. A recent article reports a spike in acidity in a large part of the Pacific Ocean, between Hawaii, Alaska and California. Also coninental shelf waters can be more affected, as is being seen by losses of clams in the US Northwest. Evidently the veliger larvae are especially sensitive to reduced saturation of Ca++.

The problem with making long-term predictions of oceanic pH values is that one is working in a poor signal-to-noise environment where short-term variations in local pH values can far outweigh any long-term trends. For example, over a two-day period in 2001 the pH values on a reef in Hawaii varied from 7.79 to 8.29, and over a ten-year period on a location in Australia's Great Barrier Reef varied from 7.71 to 8.25. The historical record apparently tells us that there has been a decline in pH of about 0.1 in the last two hundred years or so, but most of this estimate is based on indirect data rather than actual pH measurements. Predicting a drop in pH of almost 0.5 units out to the year 2270, as the IPCC models suggest, in this S/N ratio environment strikes me as foolhardy, to say the least.

There are many models of CO2/seawater interaction that can be adopted. William DeMott has suggested one, and Saif Uddin another, for which I thank you. Both or neither may be significant factors. My point is that the IPCC appears to be making long-term predictions which are not justified by the available data, taking into consideration the low S/N ratio environment in which these observations are made.

Ken

I do not know why I had to be challenged here with my eternal IPCC? As you write yourself IPCC is in the first place there to make assessments and as soon as someone launches an idea of himself I refer to the report of Working Group 1. That is based on thousands of peer-reviewed publications and written by hundreds of experts. Beats the hunch of a single individual, often, non-expert.

However, another report is that of is the workgroup 3 "Mitigation of Climate Change", still to appear.

Scientists are not just estimating changes in ocean pH by making a lot of measurements. The more direct way is to understand physics and chemistry. Given rates of fossil fuel use, we can estimate the amount CO2 absorbed in the ocean and its affect on pH. The more complicated factor is the mixing of the upper stratified layers with the deep sea and carbonate erosion and dynamics. I am not a physical or chemical oceanographer, but this is the approach that they take. Of course, these predictions should be verified by measurements.

Climate change has varied impacts on countries, and the mitigation of climate change also has rather different impacts on countries. In addition, there are in deed a lot of uncertainties with the science. All these are among the reasons why it is so difficult to reach an agreement on this issue.

Another problem is the use of the term 'climate change'. When the world was concerned with global warming, there was a fairly simple cause and effect relationship to be investigated - are human activities, and most notably the release of CO2, causing the planet to warm up? However, once we started talking about climate change, then any spectacular weather event can potentially be regarded as evidence of climate change. (No doubt the stranding of scientists on board the Russian vessel in the Antarctic will be claimed as evidence of man-made climate change.) Since spectacular weather events have occurred since the dawn of history, we are now faced with the problem of separating the signal of climate change, if any, from the noise of random weather events. We have a signal-to-noise ratio problem which has been exacerbated by replacing the concept of global warming with that of climate change.

Ken

A firs requisite for any scientist is knowing his references and nothing is easier than going to the IPCC report and the appropriate chapter and section. She who does not make this effort is not worthy of this "oasis of science" (citation).

In fact in cases that it was clear that IPCC was not even known to the people I pointed them to the respective section with a link to the IPCC AR5 report. I even guided them to the blogs of outspoken skeptics like Roy Spencer and Clive Best, who in any case are well aware of the greenhouse effect as such. Even the natural greenhouse effect is denied here in RG.

Ken

I mentioned before that I expect scientists to do their job. IPCC is the key reference for Climate Change. OK I will make an exception in a reply to you next time. I have no mercy with youngsters who can download a chapter of the report in seconds.

Matter of fact one can also download the full report. t does not take up much space and again it is the encyclopedia for Climate Change. I still have a library of reference works in my bookshelf that takes up more actual space.

As you know for preprints it is illegal to quote these in a formal publication not at a site like RG.

Ken

I went to the cited location in AR5 ch 12

You did not tell the full story: the paragraph ends with:

"that is covered by the Working Group III contribution to the AR5. [Here, we focus on the RCP scenarios used within the CMIP5 intercomparison exercise Taylor et al. (2012)

along with the SRES scenarios (IPCC, 2000) developed for the IPCC TAR but still widely used by the climate community; HtB].

I also mentioned in my previous entry that the report of WG3 still has to come out.

Ken

I fully agree that the future can not be predicted but as in weather one can make a projection with likelihood. I refer to the popular site WeatherUnderground: it has a link to the scientific forecast that I use when like today I am curious about the situation in New York where a very rapid T-plunge is expected / projected/ predicted. Glad there are weather models: this situation was already "predicted" ONE week ago. I think that is a miracle of modern time. People can take precautions.

As for the CC components:

We can quite easily handle the aerosol. would be a also the solution for air pollution.

Complete reduction of soot (black carbon) is especially beneficial and in the same time a warming component is gone

Sulfate: its reduction is very cheap and has been implemented in all countries in W-Europe. This has lead to a reduction by an order of magnitude in sulfur dioxide and sulfate in the atmosphere since its maximum back in SIXTIES, with less people around.

Finally, I am not and was never involved in WG3 reports, so I have no information on mitigation

Ken

IPCC and your idea that I should direct people to the proper place:

This is contrary to how science works. When someone has a "new" idea or does not agree with the existing knowledge it is HIS/HER duty to cite the papers he disagrees with. Then peer reviewers can go to that place and references and see for themselves. You know how peer review works in this case.

As for PhD students: they should find their relevant literature. I was very disappointed when students did not make the effort to go to the central national academic library and I personally went / had to go instead in the time when we did not have internet.

Harry

Ken

I agree with you when it is a sincere scientific question, but again, when someone is STATING his uninformed opinion he/she rather starts to google IPCC and the relevant keyword.

The IPCC report is NOT an encyclopedia but the key reference point for climate change science produced by hundreds of experts, beats any general encyclopedia on the subject.

What do you think I know the IPCC-bible by head? And moreover I am not an expert in the areas covered by IPCC. Still, when I see a statement in a blog or new publication first thing I do is just what I mentioned. In earlier days one had to go to a library to search physical or chemical contents for publications. Via google it is very easy to find the relevant section in the report. \

Did you try it?

I think the problem here is that we are confusing scholarship and science. Scholarship is basically a matter of knowing who wrote what and when, and is as necessary for specialists in, say, Chinese literature as it is for specialists in atmospheric physics. Science, on the other hand, is a discipline which demands first, verifiable physical observations, second an ability to develop a hypothesis to explain those observations, and third, and most important, a willingness to entertain any further observations which may disprove the hypothesis. An excellent example of this is the development, over several decades, of quantum theory from Max Planck's original quantum hypothesis in 1900.

My observation has been that climate change devotees, while diligently working on the first two of these requirements, fall grievously short on the third. Almost any weather phenomenon nowadays is claimed as proof of anthropogenic global warming (although it is usually disguised as 'climate change'). Thus we have so-called scientists on board an ice-bound Russian vessel in the Antarctic claiming their predicament is due to global warming. This is not science. it may be politics or it may be religion, but science it is not.

Back to the original question: Even if a person accepts climate change science, an "agreed upon solution" would require changes in law and policy. On the climate mitigation side, reducing GHG emissions requires a fundamental shift in our carbon-based economy that would shift current winners and losers--never an easy situation for changing societal norms. However, on the climate change adaptation front, some approaches ARE emerging -- but adaptation is necessarily a more local endeavor, and there is no one-size-fits-all solution.

Roger,

I think you are right in one thing: no single weather phenomenon can be claimed as a proof (or, by the way, a disproof) of global change or global warming. But I do not think any scientist does. This is a matter of press and uninformed activists.

There is a good explanation about that in a post to another question here in ResearchGate: See Guillermo Auad answer to the question "What is the cause of this recent northern air mass arctic blast pushing into Midwest. A sign of climate change or just weather extreme?"

https://www.researchgate.net/post/What_is_the_cause_of_this_recent_northern_air_mass_arctic_blast_pushing_into_Midwest_A_sign_of_climate_change_or_just_weather_extreme?cp=re65_x_p2&ch=reg&loginT=byuCgfwkxINhFrjj3x2G8mw8Vn8AOsu81T9X5S7icOc%2C&pli=1#view=52cfe726cf57d782488b4597

However, let me say that Climate Science Scientists (I do not know about devotees) have worked hard in the third requirement: you can see that in the refinement and expansion of IPCC reports, impelled at least partially to cover the criticisms posed by climate change skeptics.

Xavier

I think that this acclamation of the procedure of IPCC will not be appreciated by a person who considers the IPCC report "shoddy", as mentioned in an earlier entry by Roger

Well, Harry, I hope somebody will

Ken

You are right: googling sends you to the popular version of the IPCC report, unfortunately. This apparently must have happened to Boris Winterhalter: in his case I directed him to the full report, avialbale at the IPCC site. Still I am of the opinion that any serious SCIENTIST with a scientific interest in Climate Change must know where to find the IPCC-report and find the respective subject of his interest. If not, I at least do not consider it worth to react to a STATEMENT of such an uninformed person. Again, this is different from a serious QUESTION, asked in all honesty.

Worse, we have contributors to this entry entitling the IPCC-report "shoddy".

Let me give you an example of what I mean by failing to accept data which may disprove a theory.

Verifiable observation: the Arctic is melting

Hypothesis: melting is due to man-made global warming

Contradictory observations:

1. An identical arctic melting was noted 90 years ago. See the following report in the Washington Post of Nov. 1922:

http://docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf

2. Some 70 years ago, in the 1940's, the St Roch, a 300-ton wooden schooner operated by the Royal Canadian Mounted Police, sailed in both directions across the Arctic Ocean (the Northwest Passage), and conducted general operations in Arctic waters for a period of several years. Since the St Roch had no ice-breaking capabilities, there must have been clear water for her to operate in this manner.

3. During the period 1960-1990, it is well documented that Arctic ice was at a maximum. Then, sometime in the 1990's it began to melt again. We therefore have the phenomenon that melting occurred in the 1920's, before any large amounts of CO2 were emitted into the atmosphere, and then freezing began again from about 1960 onward when CO2 emissions began to approach their present-day levels.

All of this suggests that the Arctic has a freeze/thaw cycle of about 70 years, and consequently there is no need to invoke man-made global warming to explain the present melting, since we are more or less at the peak of the warm period. Yet where is this discussed in the IPCC report.

Roger,

"there is no need to invoke man-made global warming to explain the present melting". Glad to see you accept the melting is true. At least this is a point you and IPCC agree (me too, but this is mostly irrelevant). However, this kind of arguments fails in logic. First, in those multicausal events just looking for a causal event in some or many cases is not enough to demonstrate that this is the cause in any specific event. And second, and most important, the man-made global warming is not a cause that will substitute all others, but a cause that adds to all others. This is a general understanding across the IPCC report, and can be seen, for instance, in Figure TS9 or TS12 of the Technical Summary of the IPCC AR5 report, were experimental data are related to multicausal explanations (models) including, or not, man activity. I am sure you will find other pertinent figures and tables in chapter 10 of the report, that deals specifically with causality attribution.Again, I refer you to the very concise explanation of Guillermo Auad in my previous post in relation with the explanation of specific events versus trends.

So, if the 70 years cycle exists and is independent from any human activity, it's Ok. The question is if the present melting is faster, more intense, etc than the others you mention and if this can be related to human activity.

Finally, a consideration: the climate itself is a highly complex subject, climate change is the complex part of the complex subject, and the cause of the rapid change in the last decades / century in at the top of this complexity. The consensus on the existence of climate change and the relevant contribution to it from human activities (on top or besides or in spite of other causes) does not rely from a handful of phenomena or a couple of time series. It's a huge amount of observations, variables and processes that feed it. And not all of them with the same relevance. So I will admit that probably some or even a relevant portion of them might not be linked to human activity at the end although some preliminary evidence had been found and a theoretical basis might exist(see, for instance, Table 1 of the Summary for Policymakers: the human influence in the duration and intensity of drought events up to now deserves low confidence, although the projections of the models make it likely (medium confidence) for the late 21st century). However, this will just result in a better knowledge of the real extension and impact of climate change and of human activity influence on it, but the fact of the climate change and the human part on it will stay, unless our advance in knowledge leads us to the conclusion that no process is affected, which seems not realistic at this time.

Why is there no solution ? We all like to drive, stay warm, stay cool,

and burn fossil fuels.

There are billions of us doing that same thing.

There is a large degree of consensus among climate scientists that humans are affecting climate and that the effect will increase in the future. But politicians will have to decide on the solutions. As long as they CHOOSE not to believe the specialists in the field, there will not be a solution.

You could also turn it around and say that apparently the climate scientists FAIL to convice politicians and the public about the state of scientific knowledge on the subject.

In any case it seems that communication between scientists and politicians is one of the problems.

Another problem is that many people are afraid that the solutions mean that we need to give up our current luxurious way of living (in the developped world that is). So they prefer not to think about the solutions.

In many cases however considerable energy savings can be reached easily, and you save money at the same time. Alternative ways of generating energy (apart from fossil fuels) should also contribute to the solution. And of course we need to keep looking for new solutions. There is no single solution (no silver bullet), but we will need a whole suite of measures. Many of these are already available. It is time that we take decissions to make these measures effective.

To summarize: We know enough, it is time for action

In order to convince the politicians you also have to convince the public at large (unless you happen to live in a dictatorship), and this you have signally failed to do, for a number of reasons:

1. The climate change case has been overstated, in order to shock the public into taking action (see the Stern Report for an example). By doing so, the climate science community has underestimated the intelligence and capacity for understanding of the general public. It is well said that you can fool some of the people all of the time, and all of the people some of the time, but you cannot fool all of the people all of the time.

2. By this means, and by allowing historically inconsistent data to be published such as the hockey stick graph of the 4th IPCC Report, the climate change community has squandered much of the goodwill that it might otherwise have claimed.

3. Climate is a naturally time-varying, noisy signal. Looking for evidence of human-caused climate change is, in effect, looking for a small signal against a very large noise background. Engineers and scientists used to dealing with concepts such as error budgets and signal-to-noise ratios would find the assignment of confidence levels in the IPCC reports somewhat lacking in rigor.

To summarize: there appears to be a built-in bias in the climate change community to find evidence of human-caused climate change. If you look long enough at a noisy signal, you can generally find evidence of anything you want.

I do agree with point n. 1 placed by Roger Graves. Not with the other 2: I do think that IPCC report (AR5 now), and more importantly, the literature in which it is based, deal well with uncertainties and noise to signal ratios, among other things, and their assertions of human activity participation in climate change are correct.

But, yes, the need to get the attention of the public on climate change has led to some scientists and many activists to exaggerate the facts (that are serious enough per se), falling into a catastrophism that has attracted the media to proclaim the message at the cost of some credibility when more clear information has been available. For instance, the repeated use of single extremes to illustrate climate change has harmed the credibility and confused the public,

Hi Roger,

Thanks for your response. I agree we should also (or first) convince the public at large.

A small factual correction: The hockey stick graph appeared in the third IPCC report (2001) and not in the fourth IPCC Report (2007). The report itself contained a whole suit of proxies, but in the summary for policy makers only the Mann et al. proxy (the hockey stick) was published for clarity. This was obvious an error, since there are many more proxies on the Earth's climate during the past millennium and the hockey stick is not the best one to portrait the global climate. However the Mann et al. publication was just one of many publications on the subject. Its importance should not be overestimated.

It is pretty obvious the climate is changing. Not only form climatic variables, such as temperature and precipitation, but also form many other observations, such as polar ice, glaciers, sea level, flora and fauna. But climate is always changing.

To prove that it is human-caused is much more difficult. For that we partly have to rely on models. Models are by nature imperfect, since they are an approximation of reality. I can understand that many people have their doubts about trusting these imperfect models. I personally think, that although they might not be correct in detail (partly because of the noisy character of the climate), they at least give us an idea in which direction we are moving.

Another way to look at the causes is to look at the "fingerprints"of these causes. For example El Nino heats the surface and the troposphere, but has no effect on the stratosphere. Strong volcanic eruptions cause a heating of the stratosphere and a cooling of the troposphere and the surface. Global warming due to a more action sun will heat the surface and the troposphere, but will heat the stratosphere even more, since a more active sun emits much more UV-radiation, which is absorbed in the stratosphere. Global warming due to greenhouse gases will heat the surface and the lower troposphere and will cool the stratosphere, since it can more effectively emit long-wave radiation due to the presence of more greenhouse gases. The observations show that indeed the stratosphere is cooling, which is another indication that greenhouse gases are a good candidate for the cause. You can look at "fingerprints" in more detail by also looking at the difference between the northern hemisphere ans the southern hemisphere and at the difference between land masses and oceans. There are also differences between the different greenhouse gases. For example water vapor and methane have little effect on the stratosphere, since they are sparse there.

Concluding: I agree that we have to convince the general public and that putting the hockey stick forward so prominently in the third IPCC Report was an error. As to the causes models are important, but there is also other evidence.

Let me add something about point 3 in Roger's last post:

The assumption that human effect on climate is a small signal is a prejudice. In fact, all the work on climate change of the last decades as revealed that this signal is no small but at least comparable with the noisy background (by the way, noisy because of the complexity of causes interacting, not because it is random). I would agree that most climatologists have been looking for evidence of human influence on the climate. But that is what you do when you have an hypothesis, don't you? You look for evidence supporting it or against it. You do not just assume that it is small and reject it.

What Roger calls built-in bias is called consensus by those convinced of the human effect on climate. And yes, this consensus can be both good and bad: good because it relies on data supporting the hypothesis; bad because it can make it difficult to accept new data against the hypothesis, as has happen in any theory from the time the scientific method was established. This is nothing new and there is plenty of literature about what makes the scientific community change a paradigm in a specific subject or scientific area. At the end, it is reality, data, but there is always a hard time for those finding new data that contradict the consensus to reach acceptance that what is wrong (or more often incomplete) is the consensus, no their "faulty" data. It happened to Galileo Galilei, to Huygens (against mighty Newton), to the theory of relativity, to quantum mechanics... to climatologists advising of a climate change, to those showing a role of humans in climate change, to those putting a limit to that role... and it will happen to those showing, in the near future, several of the limitations of the present consensus. However, let me end by saying that scientific consensus has always advanced, to present, in the direction of giving better explanations of reality, not worse, completing what was explained before (the dilemma for light being a wave or a corpuscle was first resolved in favor of the latter, short after of the former, but finally in the form of a duality, the best way to explain more data; and Newton's gravitation was not substituted but enlarged by general theory of relativity: we always see more, not less). So I would not expect evidence in the next years contradicting a human role in climate change, rather clarifying its limits, maybe showing clearer boundaries in the changes to expect and in the human contribution and, why not, that this contribution is null in some aspects of climate change that nowadays we believe to be crucial.

One of the basic problem about climate change study is absence of valid data acceptable to all. Most of our projections are based on assumption and they vary from place to place. Taking advantage of that, vested interest keep on confusing mass and hence any concrete strategy to tackle it is yet to be formulated

Prashant

A basic problem is that scientists are not aware of the valid data because they rather write an uninformed entry instead of consulting the relevant literature: the scientific IPCC-report of the UN, produced by a couple of hundreds of prominent researchers in the field:

http://www.ipcc.ch/report/ar5/wg1/#.Ut0z95o1jIU

Well, Kenneth, I think you just exemplified what Prashant wrote: some people would not accept those data without correction, and some others, like yourself, consider that the correction has invalidated the data. That's it.

Kenneth

The IPCC report is an assessment, but it is not the place to assess the data of individual countries. Admittedly yours is not the smallest but for a global average it does not warrant a full analysis in an IPCC-report. Still, I remember that I gave you a reference to AR4 in an other question here in ResearchGate on the reanalysis of your national data some years ago.

You referred me to the reanalysis in my own country and vicinity then.

Question to you what are "older" data: dating from what years?

I like to remind you that an anthropogenic influence (CO2) can only be present only from the fifties onward

Any comparison of temperatures needs to consider that climate scientists use anomalies and not "average" temperature. If stations are added or subtracted, these stations contribute by comparisons of the temperature change at that particular station over overtime. Using this approach much reduces the importance of the number of stations and reduces potential biases. Statistical studies show that the number of stations, even after some have been reduced, are enough for statistical overkill. The one exception is the poles, where warming more that twice that in the temperature zone. In general there is good agreement amongst international temperature records. However, the UK HadCrut database has worse coverage of the poles and therefore underestimates recent global warming.

For comparison of warming in countries or states, the number of dailly records is useful. For example, in the US, record highs outnumber record lows by something like 4:1 since the year 2000. This disparity in local record temperatures favoring record highs has increased markedly each decade over the past 40 years but especially in the last 20 years.

Kenneth,

After reading the post from William DeMott I understand why you are so insistent on records, but still do not understand the importance (other than anecdotic or locally patriotic) of where the records are situated; what matters is frequency. It may very well be that the absolute heat record belongs to a colder decade, what matters, as William stressed, is the frequency, so unless you are suspicious that the changes made alter these frequencies, I do not see the problem.

William ... I am not sure of the logic when you say that "Statistical studies show that the number of stations, even after some have been reduced, are enough for statistical overkill." I can see how this would work if you have a clear and substantiated model of climatic variation from place to place on the Earth's surface, but is it not more likely that there are significant microclimate variations from place to place in a quasi-random fashion? If this is the case, then the fewer recording stations you have, the greater the chance of bias creeping into the measurements, as any study of random events would tell you. The only way to avoid such bias is to increase, not decrease, the number of recording stations.

@Drs Ken, Harry, William, Roger and others, an average person (like me) with no particular expertize in climate science remains unclear about the reality of climate change and global warming. Till now, what I knew from the literature is that climate is changing and the Earth is warming. But, having read the posts in this thread and in other related forum, I'm curious to know if the reality is different from what I believe.

My straight question to you all is: "Is the global warming a reality?"

Thanks

Manoj

The only advice I have is to study for yourself the so-called assessment reports of the United Nations of which the latest just came out as draft. There an overview is provided of the changes in climate parameters over the last decades and the likelihood that this was caused by emissions of greenhouse gases by mankind.

Written by the leading experts in the filed

http://www.ipcc.ch/report/ar5/wg1/#.UuNtC5o1jIU

Manoj,

The climate has certainly been warming since about 1980. The real question is, how much of this is a natural variation and how much is due to human activities.

The 1st IPCC report (1990) on page 202 gives a series of graphs showing natural climatic variation back to almost one million years ago. (I use the word 'natural' advisedly, because there was no significant human presence for almost all of that time.) It is obvious from these graphs that global temperature varies in a rather complex series of cycles. At the present time we happen to be at or near the peak of a local temperature maximum in this series, but this peak is by no means a record high.

The latest IPCC report has made the case that some or all of the temperature increase could possibly be due to human activities, but in my opinion it has failed to examine with the same rigor all the other possible causes for the current warming, of which their are many. It seems to me that the IPCC has started with the unspoken assumption that human activities are causing measurable global warming, and naturally has come to that conclusion, since it has not looked hard for any other causes.

In conclusion, human activities may be factor in the current warming trend, but I see no compelling reason to accept this as a proven fact.

Roger

It does not suffice for a scientist to write "in my opinion" and "it seems to me": It is your scientific duty to define the alternatives. Else we have to stick with the SCIENCE of IPCC

Yes, scientists who look at a large part of the peer-reviewed literature conclude that the chance that warming is caused mainly by the rapid increase in green house gases are more than 95% sure. In addition, evidence indicates that the long term trend would be for cooling but for green house gases. No one can read all of the climate literature, but reading articles closest to ones field (I read about effects of climate change on lakes) and may 5 more general articles per month should be sufficient. I would warm against trusting journalist and media as a source of news. In the US industry and right wing billionaires are spending 100s of million US per year to mislead and disceive about climate science.

Ken

OK leave out the "in my opinion" in the Roger entry and then the question remains to come with serious alternatives for the many indications of climate change as provided by "IPCC", meaning the publications that are compiled by the authors, co-authors, contributors and reviewers of the respective chapter.

Ken

Forgot to reply on your 2d issue of the original question, forgotten in the denier debate:

A first solution is less energy waste in your home country

Ken

I refer you in the first place to the technical summary of the IPCC report

TS.2 Observation of Changes in the Climate System

TS.2.2 Changes in Temperature

TS.2.2.1 Surface

TS.2.2.2 Troposphere and Stratosphere

TS.2.2.3 Ocean

TS.2.3 Changes in Energy Budget and Heat Content

etc

There you find the reference to the respective section in the report itself and there you find the references to the peer-reviewed publications

Still the US with a population of 300 M have a share to energy-waste over the last decade of 10% of the CO2 global emissions; acting that would (have) give(n) a 10% longer lee-time for doubling

Ken

Illustrative is the per capita emission of CO2

http://www.energytrendsinsider.com/wp-content/uploads/2012/07/Per-Capita-CO2-1024x696.png?00cfb7

Roger and Ken,

Adding to Harry's references, and as I wrote in my first contribution to this question two weeks ago, see Figure TS9 or TS12 of the Technical Summary of the IPCC AR5 report, were experimental data are related to multicausal explanations (models) including, or not, man activity. In simpler words, if all possible causes of climate change are considered except human activity, models do not fit to data. Similarly, if human activity only is considered, models fit better but not enough. Only when all causes are considered, including human activity, can the evolution of climate be reproduced by climatic models. This is a general demonstration of a relevant human role on present evolution of climate change, you can find the rest along the TS and all other chapters. And, please, do not ask to pinpoint a particular article in the literature: there are hundreds of them referred in the report and, as Wiilliam wrote, it is impossible to follow all of them, and this is the reason of the Report to summarize them.

So, to Manoj, yes, the earth is warming, and yes we have a great responsibility on this.

Ken, on the record question, I see you keep in the same reasoning, so I cannot add anything else. The problem is not records or were they are, but its frequency. Also, the problem is not mean temperature (is just a way to assess and summarize climate), but the variability, the extremes, its frequency... just an example: mean temperature of Barcelona, my city, and of Sevilla, south of Spain about 1000Km only (poor distance compared to the states, I know, but enough for some climatic differences) is about 1.5 Celsius. Not much, uh? But we almost never reach 40 Celsius in summer and they have records of 50, which means they could almost cultivate cotton, they cultivate oranges, but can't produce wine. We cannot have orange trees, cotton would freeze in winter but do produce wine.

So, going to your concern if climate change is affecting people's lives, it is and it will. I am not as lucky as you are and living in the Mediterranean region we are more vulnerable to climate change: although a particular drought event or heavy rain cannot be attributed to climate change, we have an increased recurrence of drought periods and intense rains, among other things (Table SPM.1 of the Summary for Policy Makers), affecting agriculture, people's houses, tourism (a central industry here). Model projections say we will be more affected in the near future, and even more by the end of the century, although this will not affect me, I will be surely dead by that time.

Thanks Xavier and Harry for your interesting posts. My question has been responded well. Can we now go back to the 2nd part of Joy's original question: "why don't we have an agreed-upon solution to climate change?"

To agree upon a solution, we would need to agree upon a cause.

Humans will never go back to not using energy for heating, cooling,

cooking, cleaning, transportation, entertainment, travel, manufacturing,

etc.

Even a complete conversion to alternative sources of energy will not

stop the changes that are accelerating planet wide. The acceleration started

with the mining of coal, and the cutting down of forests long before that.

Since the process began at least 15,000 years ago or before,

in the middle east, with only a minor increase in human population, and

the introduction of agriculture.

By 12,000 years ago the continental glaciers began melting, and the

melting process is still continuing. Humans alter the natural,

previously stabilized conditions of lower temperatures, and they will

continue to do so forever or until they become extinct.

And so to bed.

Kenneth--I thought that I posted an answer but can't find it. We have the Koch Brothers with assets of over $50 Billion US who are contributing 100's of million per year to an effort to confuse and mislead about climate science. Then we have publically funded scientists who are published peer-reviewed science. I don't see these as being in any way comparable. The most important criterion for publishing a peer-reviewed paper is support of the conclusions by data. Scientists use the scientific method to test hypotheses and are pleased when they get convincing results even if the results do not support expectations. I've been a reviewer editor for over 1200 peer-reviewed manuscripts for about 50 journals. The fastest way to get a paper rejected is to make a conclusion not support by data or to make a misleading statement about literature cited. On the denier side, the great majority of statements that I read are misleading and it's clear that any political view in a science paper is not acceptable.

I agree with almost everything Michael wrote, but just two comments: I am quite doubtful we can relate the onset of glaciers melting 12000 years ago with human presence on Earth, this is not the point of present climate change. Climate has changed continuously in the past (even before humans!) and it will in the future, and humans have altered their environment (not the only species to do that, by the way, or look to the beautiful corals, for instance). The novelty in the last two centuries is that we do that at a global scale, so migration or war to conquer new territory (the usual ancient "solutions" to exhausted environments) are not feasible anymore. And we do that in a way that the velocity of changes is much higher than in the past, so limiting adaptive responses.

Another point: humanity has gone back several times from their comfort, at least part of the humanity after every war (the losers), natural catastrophes (the victims), epidemics ... always with a reduction in the use of energy, even per capita. The point is, will we be able to do that preventively, not after any kind of social damage? (I doubt our extinction will come that way: maybe a strong loss of comfort for a majority, or for the privileged minority in the western countries, but not extinction)

Michael and Xavier, I would certainly agree that humans have had an effect on climate. For example, deforestation will cause local, and possibly not so local, climate changes. However, I take exception to the viewpoint that the human presence is a one-way trip to environmental disaster. Human efforts can improve the environment as well as harm it. The difference is that, whereas environmental degradation is easily accomplished, environmental improvement usually takes a lot of effort and a great deal of money. A good example of this was East Germany immediately after reunification. After half a century of Soviet control the country was an environmental disaster, and it has taken the financial might of the reunified Germany to improve things.

Since the original question was about climate change, yes, it is not unreasonable to assert that there is a human component to climate change. The real question is how large is this component (I am not convinced that it is very large, as you may have guessed from my previous posts.) If the climate change we are seeing is largely a natural phenomenon, we can do very little about it other than adapt to whatever changes occur. If there is a significant human component to it, we have to ask ourselves whether the cure would be worse than the disease. How many of you would like to live in a mode where the total energy expenditure available to support your lifestyles was only a fraction of what it is now? Would it not be better to place our efforts into adapting to climate changes rather than trying to reverse them?