Global Warming Question?

Summary:

Just curious about your thoughts.

Global Warming Question?

HLP1245 16 Dec 2012 20:50

So, Global warming seemed to be a hot topic last year and I've heard quiet a bit about it this year……I'm slightly confused though because some people say its nothing that should be an immediate fear….some say that it is something to be very worried about right now…and some say it is a very slow process that may not have a major impact for hundreds of years. What is your input? I'm basically over this 2012 crap but global warming concerns me…..just curious about others thoughts on it.

Re: Global Warming Question?

Andrea Drea 16 Dec 2012 20:57

problem is, this is for 2012. I believe there is an off topic forum.

Re: Global Warming Question?

HLP1245 16 Dec 2012 21:04

The problem is…you have no reason to be rude…I consider this question something to do with 2012 in a sense…I don't consider this off topic. If you have nothing helpful to say..please do not butt in with your unwanted remarks!

Re: Global Warming Question?

Gary A 16 Dec 2012 21:06

Rude? For goodness sake, you were merely told that this belongs in the off-topic section, which it does. Don't get pissy because someone has bothered to read and adhere to the rules.

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The great thing about science is, it's true whether you believe in it or not.

Re: Global Warming Question?

Andrea Drea 16 Dec 2012 21:07

Wow, unbunch your panties dude. You're the one being rude. I simply pointed out this is for talk of 2012 not global warming. Global warming has nothing to do with the 2012 "doomsday" discussion as it is not listed as one of the possible causes.

Also you said this has nothing to do with 2012, you said, and I quote "I'm basically over this 2012 crap but global warming concerns me"

That would make this off topic… and I was merely pointing out there is a forum for things not related to the 2012 Maya alleged prophecies. If you're over the 2012 crap and want to talk about other issues, there's a forum for that.

Re: Global Warming Question?

obaeyens 16 Dec 2012 21:00

some people say its nothing that should be an immediate fear

It is happening, but it is a slow process.
Best is to go to the topics of global warming to discuss any further.

Re: Global Warming Question?

HLP1245 16 Dec 2012 21:02

I have sifted through the stuff and didn't see anything on it that really answered my question

Re: Global Warming Question?

Andrea Drea 16 Dec 2012 21:07

Its called the off topic forum. Maybe if you'd head over there you'd find it..

Re: Global Warming Question?

Jantar 16 Dec 2012 21:08

I would love to answer any questions you may have on the topic of Global warming, but this isn't the place for it. I am almost 60 years old, and have recently returned to university (part time) to complete a PhD in Climatolgy/Hydrology. My thesis is studying the effects of climate drivers on river flows, so global warming and other climate change comes right into that field.

Perhaps if you bring it up in off-topic we discuss it in detail.

Re: Global Warming Question?

3WMElliott 16 Dec 2012 21:39

Hell, why don't I move this thread off topic myself and you can all continue chatting?

(Though I do hope you'll all stay on topic, even on the off topic board)

Global Warming Question? - A summary

Jantar 16 Dec 2012 22:03

I'll discuss the question of global warming in a series of posts. First I'll outline my own position, I am what is called a "Lukewarmer".

That is I believe that man (anthropogenic) is adding CO2 to the atmosphere, and that this does have some warming influence over and above natural levels. However I also believe that the anthropogenic influence is small. So small in fact that it is hidden by natural forcings.

The effect of CO2 absorbing short wavelength radiation and re-emitting long wave (Infra Red) radiation was proved in the mid-1800s, so that is not new. Natural background levels of CO2 already add around 1 C to the atmospheric temperature. However the effect is logrithmic so the temperature rise is proportional to the Log of CO2 concentration. This means that a doubling of CO2 in the atmosphere (from 280 ppm to 560 ppm) will give a small rise in temperature of around another 1 C to 2 C above background. It needs to double again to 1120 ppm to get another 1 C and double again to 2240 for a further 1 C.

So basically, I believe man does have an effect on the earth's global temperature, but that the effect is small, and even if we do add more CO2, that effect is diminishing.

The other side of the coin though is the effect man has locally. Cities are warmer than the surrounding rural areas by as much as 6 C due to the Urban Heat Island effect. Concrete and pavements soaks up heat and causes massive rises in local temperatures. Electricty is generated in rural ares and that energy is transmitted to cities. Vehicles burn most fuel in cites etc. Large airpoprts are close to cities and aircraft burn heaps of fuel when taxi-ing and on take off. So here is where man most certainly does have an effect on temperature.

Global Cooling?

Jantar 16 Dec 2012 22:21

From the end of the Little Ice Age (LIA) around 1800 through to 1940 the earth warmed at a steady rate of around 0.2 C per decade, then suddenly started dropping. There was a drop from 1855 to 1885, but the overall trend was still up.

By the mid 1960s there were fears we were entering another ice age and many papers were written on Global Cooling. By 1970 the temperature had dropped 0.7 C in the space of just 30 years. warnings were abundant about Global Cooling, and many of the same scientist who are now voicing warnings of Global Warming were the same scientists who then were warning us about Global Cooling.

Some though were pointing to CO2 as a modifying influence and saying that as we increase the amount of CO2 the effect of cooling will be reduced. They also pointed out that CO2 is a natural fertiliser, and greater concentrations of CO2 would assist tree growth and help moderate climatic fluctuations.

Last edited on 17 Dec 2012 04:25 by Jantar Show more

Re: Global Warming Question?

dylan webster 16 Dec 2012 22:50

But what of the polar ice habitats melting away?

Re: Global Warming Question?

Jantar 16 Dec 2012 23:05

The Arctic sea ice extent is diminishing, and has been doing so since the 1800s, but at the same time the Antarctic sea ice is increasing to the the extent that 2012 saw a record amount of global sea ice. The sudden drop in Arctic ice extent this year was caused by an intense polar storm that broke up the ice. It was followed by one of the fastest re-freezes on record. So not strictly temperature related at all.

Greenland is losing a small portion of its land based ice, and Antarctica land based ice is increasing. This is not my realm of expertise, but I do know that research is being undertaken on this see-saw effect of one hemisphere gaining while the other one loses ice.

Also, do not forget that Greenland got its name because during the Medievil Warm period, it grew pasture and grazed stock. It was at least 2 C warmer than the present time.

Last edited on 17 Dec 2012 04:27 by Jantar Show more

The warming data

Jantar 16 Dec 2012 23:53

From 1978 the global temperatures appeared to start climbing rapidly. Nasa and the GISS temperature sets both showed an unprecendented amount of warming. The Hadley Climate Research Unit data set (HADCRUT) confirmed this, but at a rate that had been seen previously. In 1979 climate sateelites started returning that showed a lower rate of rise. This is partly explained by the methods ofcalculation used. There isn't a global thermometer that someone can pop out and read, so all global temperatures are the result of models.

The sattelites read atmospheric IR and convert this to temperature. Thus this is not a true surface record, but a good proxy for it. NASA and GISS used land based thermometers and extrapolated this data out over the oceans. HADCRUT included sea surface temperatures where they were available and came up with data that was more correct globally, and this is the set that the IPCC have tradionally referred to. It is also the data set that I use in my studies, and is available online here http://www.cru.uea.ac.uk/cru/data/temperature/

Last edited on 16 Dec 2012 23:57 by Jantar Show more

Recent years

Jantar 17 Dec 2012 00:16

The temperature continued to rise rapidly right up to 1998. The 1997 - 1998 El-Nino produced the highest global temperatures ever recorded. However accurate records have only been kept for a very short period of time, around 100 years, and to a degree of accuracy of +/- 1 F (0.5 C) twice per day. Sparodic readings go back further, and only the Central England record at a single location goes back to the 1600s. All other temperature records have to be estimated from proxies. These proxies include tree rings, disolved oxygen, ice cores, sedimentation etc, and all have confounding influences that greatly reduce their level of accuracy. Tree rings, as an example, can be influenced as much by precititation (my research field) as by temperature.

Although there were minor dips and rises in the temperature record, the general trend was upwards, and nicely matched the rise in CO2 concentrations. Following the 1998 El-Nino there was a sudden drop in global temperatures, followed by an equally quick rise, but not up to 1998 levels. The main point was that the temperature rise sarted to deviate from CO2 concentrations. This made some scientists start to look for other causes and led to the current warmist/sceptic debate.

Since 1997 almost all years have had global temperatures that were higher than at any time on record. That is like going to the beach and starting to record tidal levels at one minute intervals from low tide, then at 5 minutes after high tide saying "Each of the past one minute samples have shown a higher tidal level that at any time since these records began".

To counter the argument as to whether Global temperatures are still trending up or not NOAA stated that there would need to be a period of 15 years without any significant rise in temperature to say that Global Warming had stopped. Prof Phil Jones of UEA stated that 17 years without any significant rise in temperature to say that Global Warming had stopped. Well, we have just reached the 16 year mark without any increase, and if anything the trend is now starting to head down.

Newly discovered climate cycles.

Jantar 17 Dec 2012 02:30

In 1997 a student in USA discovered an interesting phenomenom affecting salmon numbers. there seemed to to be a long term cycle of around 50 to 60 years where salmon numbers rose and declined. He discovered that this rise and decline in salmon co-incided with changes in the Pacific sea surface temperatures, and as a result, the Decadal Pacific Oscillation (PDO) was discovered. This research led to a further corelation with air temperatures on a similar osciallation and led to the related Interdecadal Pacific Oscillation (IPO).

The IPO had a warm phase from 1800 to 1860, a cool phase to 1885, a warm phase to 1940 a cool phase to 1975 a warm phase to 1998, and a slight cool phase until 2010. This cool phase appears that it may deepen.

These IPO phases exactly match the changes in global temperatures leading scientists to believe that natural effects are dwarfing the effects of CO2.

3 months ago a new oscillation was discovered called the Pacific Centennial Oscillation. This is an entirely new discovery and we do not yet know how it corelates with global temperatures, nor whether it is a driver or an effect of other climatic patterns.

The IPCC second order draft report has just been leaked, but the IPCC confirm that it is genuine. This draft shows that the IPCC are now accepting that solar forcing is having a greater effect of global climate than they previously believed, and that global temperatures are below all of the modelled predictions.

Re: Newly discovered climate cycles.

StrangeFruit 18 Dec 2012 01:14

Nicely done Jantar :-)

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"You are not entitled to your opinion. You are entitled to your informed opinion."

- Søren Kierkegaard

Re: Global Warming Question?

Corianin 18 Dec 2012 23:58

As an archaeologist/anthropologist/historian/geologist, I'd like to point out that there was a point in recent history (geology wise) called the Glacial Maximum, in which temperatures seem to have been slightly warmer than today's temperatures. This Glacial Maximum was followed by the Little Ice Age, which many historians believe directly contributed to the Witchcraze in Europe (the Witchcraze in Salem had a completely different cause. I did too many papers on the topics in undergrad =p). Why can't this period we're in now be another Glacial Maximum? We really have very little weather data when you look at the number of years we've been recording the weather (two or three hundred at best) compared to the age of the Earth (close to 4 billion years old, give or take a few million years).

Modern science is very young indeed, and we can't expect to know everything there is about our planet—I reference the Hueyatlco site in Mexico.