weatherwiz Posted May 1, 2014 Share Posted May 1, 2014 Been searching around but trying to find a graph which shows the average temperature of the Earth dating as far back as possible...I've found numerous graphs going back to like the 1800's and such but what I really need is something going back as far as possible. Anyone know of any great links or places I can find this info? Link to comment Share on other sites More sharing options...
PhillipS Posted May 1, 2014 Share Posted May 1, 2014 Been searching around but trying to find a graph which shows the average temperature of the Earth dating as far back as possible...I've found numerous graphs going back to like the 1800's and such but what I really need is something going back as far as possible. Anyone know of any great links or places I can find this info? Here is the paleoclimate temperature record for the past 12,000 years: Figure 1 Blue curve: Global temperature reconstruction from proxy data of Marcott et al, Science 2013. Shown here is the RegEM version – significant differences between the variants with different averaging methods arise only towards the end, where the number of proxy series decreases. This does not matter since the recent temperature evolution is well known from instrumental measurements, shown in red (global temperature from the instrumental HadCRU data). Graph: Klaus Bitterman. - See more at: http://www.realclimate.org/index.php/archives/2013/09/paleoclimate-the-end-of-the-holocene/#sthash.9lCWA83u.dpuf Link to the source article. Is that close to what you are looking for? There are other plots of temperature reconstructions going back hundreds of millions of years - just understand that the farther back we look, the greater the uncertainty of the reconstruction, at least in global terms. Link to comment Share on other sites More sharing options...
AvantHiatus Posted May 1, 2014 Share Posted May 1, 2014 Quite accurate but the temporal range is so massive that you will be unable to see much detail. This shows estimates of global average surface air temperature over the ~540 My of the Phanerozoic, since the first major proliferation of complex life forms on our planet. A substantial achievement of the last 30 years of climate science has been the production of a large set of actual measurements of temperature history (from physical proxies), replacing much of the earlier geological induction (i.e. informed guesses). The graph shows selected proxy temperature estimates, which are detailed below. Because many proxy temperature reconstructions indicate local, not global, temperature -- or ocean, not air, temperature -- substantial approximation may be involved in deriving these global temperature estimates. As a result, the relativities of some of the plotted estimates are approximate, particularly the early ones. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 1, 2014 Author Share Posted May 1, 2014 It's fairly close to what I'm looking for. I used to have some charts and such but lost them over the years. I remember being able to find charts...even dating back to like the 1500's or so would be fine. I'll explain why I'm looking for this as it may help. For my public speaking class out final speech is a persuasive speech. My topic is on the claim that global warming is leading to stronger tornadoes and more frequent outbreaks here in the US...my stance on that is we do not have enough data to make such a claim. How does that tie in to what I'm asking for? Well my first paragraph of the speech is defining the term climate change as defined by the AMS and just briefly discuss global warming and whether it's man made or caused by humans. My stance there is (and this gets to what I'm looking for) the Earth goes through cycles of warming/cooling, (and I need a temperature graph that goes far enough back to illustrate this), however, humans have most certainly enhanced this latest warming cycle the Earth has gone through. Does this help at all? Link to comment Share on other sites More sharing options...
AvantHiatus Posted May 1, 2014 Share Posted May 1, 2014 Yeah, I agree for the most part but there is probably a slight or moderate AGW signal in all weather events. Also need to keep in mind that even though the Earth has been much warmer, humans were not around to habituate these conditions and the effects would be unknown. Though, this is kind of irrelevant when linking modern tornado outbreaks to AGW. You would have to cite natural cycles like the Pacific Decadal Oscillation in order to disprove AGWs influence. I think there were more severe weather events in the 50's when the PDO was in the negative phase. Not sure though. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 1, 2014 Author Share Posted May 1, 2014 Yeah, I agree for the most part but there is probably a slight or moderate AGW signal in all weather events. Also need to keep in mind that even though the Earth has been much warmer, humans were not around to habituate these conditions and the effects would be unknown. Though, this is kind of irrelevant when linking modern tornado outbreaks to AGW. You would have to cite natural cycles like the Pacific Decadal Oscillation in order to disprove AGWs influence. I think there were more severe weather events in the 50's when the PDO was in the negative phase. Not sure though. What makes it a bit tough too is the speech can only be between 5-6 minutes long so I obviously can't get into incredible detail. This is why I just have decided to talk about climate change and tornadoes...thought it was appropriate given how we are in the spring. My first paragraph is a brief run through of the background of global warming with the two points are defining climate change and then briefly talking about whether man-made or cyclical (this is where the graph comes in hand). The second paragraph is dedicated to discussing tornado data, and again b/c of time constraints I'm limiting the data to spring months (March-May). Also, not only do you have to provide your stance but a counterargument...so my counterargument to my stance will be about how we have seen numerous substantial events the past decade...then I can counter that with briefly talking about increase in storm spotters and chasers, development of rural areas, better radars, etc. My final paragraph will then be going back to my claim...this is where I talk about how tornado records don't go back very far at all...only begin in 1950 and tornado records don't even become accurate until the 1970's and perhaps even later than that. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 1, 2014 Author Share Posted May 1, 2014 I wish I had all those links I had compiled several years back. I found some great charts which showed the average temperature of the Earth, I believe going back to the 1500's until it was I think early 200's and it showed clearly the cycles of warming/cooling but you could also see since the Industrial Revolution how the warming just escalated...even though we had periods of cooling, each decrease was less significant than the previous Link to comment Share on other sites More sharing options...
weatherwiz Posted May 1, 2014 Author Share Posted May 1, 2014 Actually I think this might be it... Link to comment Share on other sites More sharing options...
ORH_wxman Posted May 1, 2014 Share Posted May 1, 2014 The tornado database is too unreliable to really make a connection. On the one hand, we have a huge increase in the number of EF0 tornadoes reported (almost certianly due to increased coverage of spotters and dopplar radar coverage versus the early record)....but then we have stronger tornadoes actually showing a slight decrease. However, the tornado ratings themselves have enough margin for error that the decrease in stronger tornadoes may not be significant either. Link to comment Share on other sites More sharing options...
TerryM Posted May 1, 2014 Share Posted May 1, 2014 Is it probable that cyclonic storms are tracking further north at this time. Not an increase in frequency nor severity but a movement north into Canada. Believe Wiki has a page on Canadian tornadoes over time. Terry Link to comment Share on other sites More sharing options...
weatherwiz Posted May 1, 2014 Author Share Posted May 1, 2014 The tornado database is too unreliable to really make a connection. On the one hand, we have a huge increase in the number of EF0 tornadoes reported (almost certianly due to increased coverage of spotters and dopplar radar coverage versus the early record)....but then we have stronger tornadoes actually showing a slight decrease. However, the tornado ratings themselves have enough margin for error that the decrease in stronger tornadoes may not be significant either. I remember several years back when I was doing alot of number crunching and such (actually I think I did one of my lightning talks on it like back in 2008) it was amazing how much the average number of tornadoes increased after 1992 which was virtually the beginning of the Doppler Radar era. When it comes to really comparing strength it's an incredibly sensitive debate b/c then you have to consider building structures which leads into an entirely different debate. Link to comment Share on other sites More sharing options...
weatherwiz Posted May 1, 2014 Author Share Posted May 1, 2014 Is it probable that cyclonic storms are tracking further north at this time. Not an increase in frequency nor severity but a movement north into Canada. Believe Wiki has a page on Canadian tornadoes over time. Terry The Canadian prairies (I believe that's what they are referred too) actually are a great spot for tornadoes as well...in fact, I believe that area is like only 2nd or 3rd to the United States in terms of # of tornadoes per year. It's really tough though to say if it's because of anything related to pattern shifts or b/c there are alot more people now around that area and who chase there, therefore, more and more become documented...perhaps it is a mixture of both but it's just so difficult to say. Link to comment Share on other sites More sharing options...
TerryM Posted May 2, 2014 Share Posted May 2, 2014 weatherwiz Underreporting of low magnitude events should be a given, but larger storms that leave long lasting scars have also increased. It's much more difficult to attribute this increase to better tracking technology. Terry Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted May 2, 2014 Share Posted May 2, 2014 Is it probable that cyclonic storms are tracking further north at this time. Not an increase in frequency nor severity but a movement north into Canada. Believe Wiki has a page on Canadian tornadoes over time. Terry Agree there are multiple fundamental reasons to believe conditions for severe weather will continue to move North. In NA snow cover will play a big factor in that. If we see a massive decrease in March/April Canadian snow cover over the next century then surely the storm track will move further North overall. Link to comment Share on other sites More sharing options...
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