date: Thu Feb 28 12:50:55 2008 from: Phil Jones subject: Re: cold winter in context... a story to: Andrew Revkin Andy, It does seem to be jumping on a bit of cold weather. We do a press release every year - even this is slightly too often. I've never done one about an individual month. Occasionally journalists call about warm periods, but I give them the message I've given you. The skeptics also leap on any paper that supports their views and ignore most others - or try to pour cold water on them. They mostly look at observation papers and ignore modelling ones, as they believe by default models are wrong! Cheers Phil At 12:28 28/02/2008, you wrote: great. thanks very much, phil. what's amusing, in a way, is how the 'skeptics' jump on a cold patch as evidence of global cooling but attack enviros for highlighting warming trend. Andy, HadCRUT3 numbers on the Watts website are OK. As has been said the Jan08 value is just one month. The NH winter and last autumn have been cool, but this was to be expected given the ongoing La Nina event. The ENSO phase often changes around April/May so keep a watch on the equatorial Pacific over the next few months. We could go into an El Nino, stay in La Nina or go neutral. Based on the La Nina state we are in (and were in at the start of the year) the Met Office and UEA issued a forecast for 2008 (for global T). [1]http://www.metoffice.gov.uk/corporate/pressoffice/2008/pr20080103.html Forecast was for a cooler year in 2008 - coolest since 2000. As has been said natural variability dominates on monthly to up to 2-3 year timescales. Some of this natural variability relates to ENSO, but there is also NAM (NAO) and SAM as well - the latter on slightly shorter timescales than ENSO. Large El Nino's tend to warm annual global T by about +0.1-0.15 deg C (as in 98) while La Nina's cool by similar amounts. Global T also tends to lag the ENSO phase by about 6 months. These fluctuations on interannual timescales are almost an order of magnitude larger than the +0.02 deg C per year expected from anthropogenic influences. Natural variability has always been with us and will continue to be so in the future. Anthropogenic influences more on decadal and longer timescales. If you look at the map for Jan08 you'll see that Northern Europe has been well above normal, but not near record levels. In the UK snowdrops and crocuses have been out for weeks, daffodils out now and blossom on many trees also out several weeks early. We've been lucky this winter, but it is down to a positive NAO. A positive NAO also tends to make the Eastern Mediterranean and the western Middle East experience a cool winter. The typical NAO influence on eastern North America is less evident, but this is probably due to the stronger La Nina influence. Cheers Phil Cheers Phil At 20:23 27/02/2008, Andrew Revkin wrote: As you all are aware, a very vocal and plugged-in crew has been making much of the recent downturn in temps. Because the 'Average Joe' out there is only hearing radio soundbites about the sun turning off, or cable-news coverage or some stray TV image of snow in baghdad (and particularly with a big 'skeptics conference' coming next week), I think it's important to do a story putting a cold stretch in context against the evidence for the long-term warming trajectory from greenhouse forcing. Would need input from you by end of Thursday ideally. I've already queried a heap of Arctic hands on sea-ice fluctuations with intrsting responses (as I wrote 10/2/07, it's still mainly first-year thin ice, and -- by volume of sea ice -- there ain't much). Also need to explore questions related to solar trends. First request (for those of you from the four groups tracking temps) is for you to to look at the data below. Anthony Watts has (potentially usefully, if the data are accurate) compiled the four main ongoing efforts to track things. Can you tell me if the datasets he's used are correct for your groups?? here's text file [2]http://wattsupwiththat.files.wordpress.com/2008/02/4metrics_temp_anomalies.txt here's his graph [3]http://wattsupwiththat.files.wordpress.com/2008/02/giss-had-uah-rss_global_anomaly_1 979-2008.png We'd like to explore this graphically as well, perhaps looking at winter temps in isolation, or just doing something akin to what's been done above. And then there are the substance questions. I'd love it if you'd weigh in on any or all, either in an email or call. 1) How unusual is the current downturn? In particular, in relation to ENSO and other cycles that might cut the other way etc? Any 'easy' explanations, or is it good old-fashioned variability? 2) Anything pop out when you look at the hemispheres as opposed to global? 3) Do you see ANY evidence of solar activity playing a role, either background or foreground? 4) Presumably global HEATING is continuing apace, even as global TEMP fluctuates. Is that right, and/or are there ocean data showing ongoing heating of seas etc? 5) The folks using the cold snap to attack greenhouse theory include some of the same people who blamed 'hot heads' for using hot years to support their view of what's coming. Does that seem the case to you ? 6) Takehome message? As always, your thoughts are much appreciated. Feel free to respond to me alone or to the group to inspire some multi-logue. -- Andrew C. Revkin The New York Times / Science 620 Eighth Ave., NY, NY 10018 Tel: 212-556-7326 Mob: 914-441-5556 Fax: 509-357-0965 [4]www.nytimes.com/revkin Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ---------------------------------------------------------------------------- -- Andrew C. Revkin The New York Times / Science 620 Eighth Ave., NY, NY 10018 Tel: 212-556-7326 Mob: 914-441-5556 Fax: 509-357-0965 [5]www.nytimes.com/revkin Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ----------------------------------------------------------------------------