Ottawa Blizzard Posted April 9, 2012 Share Posted April 9, 2012 The Canadian Weather Network will be airing a series in which weather and climate experts question just what is up with our weather. Why was this winter so warm? Why the heatwave in March? Is it a sign of an unstable world to come? http://www.theweathernetwork.com/news/storm_watch_stories3&stormfile=What_s_up_with_the_weather__30_03_2012?ref=ccbox_homepage_topstories Link to comment Share on other sites More sharing options...
donsutherland1 Posted April 9, 2012 Share Posted April 9, 2012 Ottawa Blizzard, Please keep us posted. Many of us don't have access to Canada's Weather Network. Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted April 9, 2012 Share Posted April 9, 2012 If they try to tie the heat wave to AGW. I hope they atleast try to show some causation and not weak correlation. Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted April 9, 2012 Share Posted April 9, 2012 If they try to tie the heat wave to AGW. I hope they atleast try to show some causation and not weak correlation. Link to comment Share on other sites More sharing options...
TerryM Posted April 10, 2012 Share Posted April 10, 2012 If they try to tie the heat wave to AGW. I hope they atleast try to show some causation and not weak correlation. Don;t get your hopes set too high. The Canadian Weather Network is primarily owned by Pierre L Morrissette, a banker who founded the Institute for Entrepreneurship.While I haven't (yet) been able to find ties to our present Conservative government, the name of the institute may be indicative. Canada's conservatives have proven to be dismissive of global warming and have a reputation for staying on message. If Mr Morrissette is a player on their behalf, opinions delivered by his network might prove slanted. Terry Link to comment Share on other sites More sharing options...
skierinvermont Posted April 10, 2012 Share Posted April 10, 2012 If they try to tie the heat wave to AGW. I hope they atleast try to show some causation and not weak correlation. That is not possible. To show AGW causation requires forensic meteorology and/or delving into butterfly-effect type physical questions. It is not possible to answer such counterfactuals given the butterfly effect. It would be reasonable to conclude that given AGW has warmed the 45-65N latitude band ~1.5-2C (just guessing) over the last hundred years, and most of this is attributable to humans, that AGW contributed an additional 1.5C to the heatwave and a similar weather pattern would have yielded temperatures 1.5C cooler a century ago. Of course even that gets into some complicated butterfly-effect questions as well because CO2 climate change has changed weather and it is basically impossible to un-link the two. It's not really possible to have the "same" weather pattern in a world absent human CO2 emissions because CO2 has changed everything from temperature, to water vapor, to geopotential heights, to blocking patterns, to arctic sea ice extent. Other than that, the only possible thing to conclude is that while AGW cannot be definitively proven to cause specific weather events, particular events are becoming more common with AGW. Also, colloquially speaking we often say that X has caused Y when the probability of Y is much lower without X than with it. For example, if I got salmonella poisoning after eating a raw moldy piece of chicken I would probably tell people that eating the raw moldy chicken caused me to get salmonella even though I have conducted no forensic medicine (like testing the raw moldy piece of chicken to see if it contained salmonella, seeing if the strain of salmonella I have matches that of the raw chicken etc.) and it is possible although highly unlikely that I got salmonella from another source (my worst enemy snuck into my house at night and injected me with salmonella). The frequency of salmonella poisoning increases dramatically after eating raw moldy chicken, thus I say eating raw moldy chicken caused my salmonella. Likewise, the frequency of record-smashing heatwaves increases dramatically after belching 100+PPM of CO2 into the atmosphere, thus we say AGW caused our record-smashing heatwave. We only say that X has caused Y when the probability of Y without X is sufficiently low. I believe the probability of such a record smashing heatwave without modern CO2 concentrations is sufficiently low enough to say that the heatwave was caused by AGW. Other more 'normal' heatwave do not meat this threshold. Only due to the fact that this is probably a 4 or 5SD event without AGW can we begin to use the "C" word. Link to comment Share on other sites More sharing options...
Jonger Posted April 10, 2012 Share Posted April 10, 2012 People comment on events and only remember events. Nobody recalls where they were on the boring normal days of the week. If next winter is normal, these stories will cease until the next time something is abnormal. Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted April 10, 2012 Share Posted April 10, 2012 That is not possible. To show AGW causation requires forensic meteorology and/or delving into butterfly-effect type physical questions. It is not possible to answer such counterfactuals given the butterfly effect. It would be reasonable to conclude that given AGW has warmed the 45-65N latitude band ~1.5-2C (just guessing) over the last hundred years, and most of this is attributable to humans, that AGW contributed an additional 1.5C to the heatwave and a similar weather pattern would have yielded temperatures 1.5C cooler a century ago. Of course even that gets into some complicated butterfly-effect questions as well because CO2 climate change has changed weather and it is basically impossible to un-link the two. It's not really possible to have the "same" weather pattern in a world absent human CO2 emissions because CO2 has changed everything from temperature, to water vapor, to geopotential heights, to blocking patterns, to arctic sea ice extent. Other than that, the only possible thing to conclude is that while AGW cannot be definitively proven to cause specific weather events, particular events are becoming more common with AGW. Also, colloquially speaking we often say that X has caused Y when the probability of Y is much lower without X than with it. For example, if I got salmonella poisoning after eating a raw moldy piece of chicken I would probably tell people that eating the raw moldy chicken caused me to get salmonella even though I have conducted no forensic medicine (like testing the raw moldy piece of chicken to see if it contained salmonella, seeing if the strain of salmonella I have matches that of the raw chicken etc.) and it is possible although highly unlikely that I got salmonella from another source (my worst enemy snuck into my house at night and injected me with salmonella). The frequency of salmonella poisoning increases dramatically after eating raw moldy chicken, thus I say eating raw moldy chicken caused my salmonella. Likewise, the frequency of record-smashing heatwaves increases dramatically after belching 100+PPM of CO2 into the atmosphere, thus we say AGW caused our record-smashing heatwave. We only say that X has caused Y when the probability of Y without X is sufficiently low. I believe the probability of such a record smashing heatwave without modern CO2 concentrations is sufficiently low enough to say that the heatwave was caused by AGW. Other more 'normal' heatwave do not meat this threshold. Only due to the fact that this is probably a 4 or 5SD event without AGW can we begin to use the "C" word. Great post. Link to comment Share on other sites More sharing options...
Jonger Posted April 12, 2012 Share Posted April 12, 2012 http://classic.wunderground.com/global/stations/71913.html Cold in Churchhill, MB compared to normal. Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted April 12, 2012 Share Posted April 12, 2012 http://classic.wunderground.com/global/stations/71913.html Cold in Churchhill, MB compared to normal. According to the link u posted the averages are 19/3f, yesterday 32/3 today its 14f right now Link to comment Share on other sites More sharing options...
LithiaWx Posted April 12, 2012 Share Posted April 12, 2012 According to the link u posted the averages are 19/3f, yesterday 32/3 today its 14f right now Friday Sunny. High -13C(8F). Saturday A mix of sun and cloud. Low -17C(1F). High -16C(3F). Sunday Sunny. Low -21C(-6F). High -15C(5F). Link to comment Share on other sites More sharing options...
PhillipS Posted April 12, 2012 Share Posted April 12, 2012 Friday Sunny. High -13C(8F). Saturday A mix of sun and cloud. Low -17C(1F). High -16C(3F). Sunday Sunny. Low -21C(-6F). High -15C(5F). I'm puzzled as to what forecast you're looking at. The link you provided ha the forecast of: Thursday 6/0 F Friday 8/1 F Saturday 3/-5 F Sunday 4/0 F Monday 13/0 F As Friv pointed out, the normal temp for today is 19 F. This just appears to be a cool spell - is there something we're missing? Link to comment Share on other sites More sharing options...
Jonger Posted April 12, 2012 Share Posted April 12, 2012 I'm puzzled as to what forecast you're looking at. The link you provided ha the forecast of: Thursday 6/0 F Friday 8/1 F Saturday 3/-5 F Sunday 4/0 F Monday 13/0 F As Friv pointed out, the normal temp for today is 19 F. This just appears to be a cool spell - is there something we're missing? Computer generated forecast changed it appears... It had shown it colder earlier... Link to comment Share on other sites More sharing options...
PhillipS Posted April 12, 2012 Share Posted April 12, 2012 Computer generated forecast changed it appears... It had shown it colder earlier... Okay Link to comment Share on other sites More sharing options...
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