Dave’s information is interesting in how typical it is for us to discount previous events when we discuss current events. An important fact to also note is the mention of the use of a 30 year average of the temperatures in the evaluation. This lessens the actual change in this year’s temperatures. The last three decades have been warmer than the average of the entire historical record. What this means is this year is still warmer than the long term average. We face the same error when the present snowpack is evaluated. It also uses a thirty year running average. The current thirty year average is also in decline compared to the historic record. The current snowpack of the Platte River basin being 120 % of average could in reality be less than the average over a longer period. To carry this further, the current level of atmospheric CO2 of over 395 ppm would be only 25 ppm above the average of the last thirty years while it is 115 ppm over the average high of the interglacial periods for the last 720,000 years and the average prior to the industrial revolution. Norm Erthal Arvada, CO
> During survey work this AM I was struck by the state of slow leaf out in > the cottonwoods. It made for amazing observing conditions for arriving > migrants, and it seems many species will arrive before well ahead of the > majority of leaf out, making for great but odd observing conditions. I was > especially struck by seeing Warbling Vireos and Orchard Orioles on bare > branches today! > > --Scott > > Scott E. Severs > Longmont, CO > -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/ccadc429-59ca-4a1f-9d21-8e3701c1fc48%40googlegroups.com?hl=en-US. For more options, visit https://groups.google.com/groups/opt_out.
