Wine Enthusiast Magazine
SubscribeDoes the Worst Frost in California Wine Country Since 1972 Disprove Global Warming?
by Jim Gordon
Everyone in the California wine industry has been buzzing about the severe frosts this spring. Since I first posted on this topic on March 19, we’ve had a series of nights when the temperature dipped below freezing.
When I first wrote, it was merely the threat of damage to the young spring growth on the vines that was the issue. Then about 10 days ago it was no longer a threat but real damage. Growers in many parts of the state, and in fact in many different states, had new spring growth nipped in the bud or frozen in the shoots by unsually cold temperatures.
What does this tell us about global warming?
Many, including frequent commenter on Unreserved, a long-time California winemaker who goes by the nom de blogue of Morton Leslie, agrees it’s been one of the worst spring frost seasons in Northern California vineyards in 40 years (see his take in the comments here). Morton doesn’t look like he’s been around that long, but I guess he has. Grower Andy Beckstoffer of Napa and Mendocino says it could be the worst frost damage since 1972. Others have similar opinions in this Wine Enthusiast article.
Some have said that the frost is evidence that global warming is a myth. That the severe cold is the opposite of warming. Sometimes I get the feeling that people who don’t believe in human-caused climate change are the ones who thought fluoridated water was a communist plot.
Attending wine industry conferences and listening to PhD. laureates who unanimously accept climate change as a consequence of human behavior has convinced me in the past two years even more than Al Gore has, that climate change is real.
So maybe there’s a chance that it’s just a cycle of nature. Still, people need to react to the change to ensure that they continue to live and prosper. They’re doing just that in the wine industry, rather than waiting for something worse to happen.
Grape growers are considering how to adapt. Winemakers are realizing they can buy grapes from previously too-cool regions.
And the frosty spring weather is a perfect example of why scientists now call the phenomenon “climate change” and not “global warming.” Gregory Jones is an associate professor of geography at Southern Oregon University and one of the leading authorities on how climate change is affecting, and is expected to continue affecting, wine. Dr. Jones grew up at a winery, Abacela, in Oregon, started by his parents. The Catavino blog ran a good interview with Greg recently.
He joins many other scientists in pointing out that what we’re seeing is generally warmer temperatures, but equally indicative of climate change is a more frequent occurrence of dramatic weather incidents, like hurricanes, droughts, floods and presumably, frosts.
Is it logical to believe that the coldest spring in a generation is further proof OF climate change, and not proof AGAINST it?
Filed under: Industry Issues, Vineyards
21 Comments
21 Responses to “Does the Worst Frost in California Wine Country Since 1972 Disprove Global Warming?”
Please Wait
April 30th, 2008 at 12:44:18 AM
Climate change can mean any climate different from the one right now. And because the earth is always getting warmer or hotter the term applies to any and all climate situations.
This is not a scientific theory because it is not falsifiable. There is no observation that could not confirm climate theory, no discrimination of data, or predictions that must be met.
April 30th, 2008 at 10:37:57 AM
Jim,
I’ve been writing since 2005 that California seems to be getting colder. A few weeks ago, shortly before the recent freeze, I had an email exchange with a friend of mine who is a TV weather reporter with one of the big Bay Area stations. In response to my question (“Is California getting colder?”), he replied:
Hi Steve!
You’re treading on controversial ground but valid nevertheless. Read this:
Global temperatures will drop slightly this year as a result of the cooling effect of the La Nina current in the Pacific, UN meteorologists have said.”
“The World Meteorological Organization’s secretary-general, Michel Jarraud, told the BBC it was likely that La Nina would continue into the summer. …
“This would mean global temperatures have not risen since 1998, prompting some to question climate change theory. …
“El Nino warms the planet when it happens; La Nina cools it. This year, the Pacific is in the grip of a powerful La Nina.
“It has contributed to torrential rains in Australia and to some of the coldest temperatures in memory in snow-bound parts of China.
“Mr. Jarraud told the BBC that the effect was likely to continue into the summer, depressing temperatures globally by a fraction of a degree….”
The warm-up in the West has been in the Southwest! You must remember though, lots of the data, especially from the Colorado River, and were taken in the 70s when there was a lot of snow and colder conditions. Let’s face it; much of that area is a DESERT!
I could go on but I think this gives you something to go on. You can write me again or call if you want to take it a step further. One last thing: many of the National Weather Service thermometers are located in urban areas, surrounded by concrete, buildings, etc. I find some of the data very suspicious. Finally, March 2008 Climate:
Temperature were at or slightly below normal along the northern and central coast and near to slightly above normal through the Central Valley. On South Coast, Los Angeles was a little over a degree above normal, while San Diego was about a degree below!
* * *
Anyhow, Jim, it’s an interesting topic.
April 30th, 2008 at 1:56:41 PM
Part of warming and change is erratic temerature and climate. Have you seen how hot it got in California this past week? We’re still in April. Climates go through cycles.
Steve,
I think you just “outed” those winemakers who attribute rising alcohol levels to climate change ;^)
April 30th, 2008 at 2:40:36 PM
True, it’s not falsifiable. But the research and observation is conducted using scientific method. just because it’s difficult to prove shouldn’t discredit it.
also it’s misnamed, global warming doesn’t simply mean everything gets warmer. it has to do with the global climate. An increase in temperature in the southwest will be compensated for in another part of the country due to the relationship between air pressure and temperature. same thing with floods/drought, the water dries up in one area but causes heavy precip somewhere else. The weather systems are always trying to find an equalibrium and man-made extremes are causing extreme responses (floods, hurricanes, heat, cold, etc)
…”much of the data was taken in the 70′s”. What? That’s just not true, meteorological records are kept every year. Why would anyone compare temperatures using just one decade? I guess if you’re looking to convince people that climate change is a myth.
I don’t buy the el nino/la nina thing, those are just names assigned to the trend when meteorologists thought it was a fluke. climate change is happening.
Lastly I love the comment about floridated water. It seems like even the biggest disbelievers are quietly admitting that something might be happening here.
April 30th, 2008 at 4:27:17 PM
It’s really quite interesting to hear various opinions about “Global Warming”, the buzz phrase of the first decade of the 21st Century. How anyone can make a determination based on a single occurence simply amazes me. In the story someone claims this was the worst in 40 years. That means these events have occurred in the past. I live in the desert in Southern California. So far this past winter we broke no records (hot or cold), no above average rainfall and temps overall probably slightly below average.
Now I have heard about the ice caps melting. I was not around during the ice age, maybe some of you were, I wonder if the cavemen were complaining about “Global Warming.
The point is how can anyone make an intelligent judgement about climate change when we have climate change all the time.
It is important that we do protect the enviroment for future generations, for my grandchildren and their children. It just bothers me with the “chicken little” type statements on any change in the weather norm.
April 30th, 2008 at 4:59:21 PM
I am surprised to see how little research has been done here and how many false assumptions are being made.
I guess it is the historically low incidence of frost in Napa Valley that has lead to such assumptions being so readily made.
Research will show that after a dry period leading into the Spring as we have just had there is a greater chance of frost. In other words, drought like experiences which we are currently suffering lead to less precipitation and the higher chances of dry days that are followed by freezing nights with low or no cloud cover. In Australia, the worst frost years happen following drought in the previous Autumn/Winter period.
In some ways this may support the global warming theory. Afterall, drought seems be an indicator. It remains to be seen if this is an ongoing change or a one year discrepancy.
Just because we have had a frosty night does not mean it is getting colder! In this case, the opposite is probably closer to the truth.
April 30th, 2008 at 5:00:11 PM
re: Jim’s post: Like everyone else, I’m following the debate concerning global warming. I try to keep an open mind and listen to as much evidence, pro and con, as I have time to absorb. But when I read Jim’s post, I felt that he has his mind made up, perhaps for political or ideological reasons. I do not think anyone is in a position to state that global warming is NOT happening, and to refer to “chicken little” simply is an ad hominem attack on people he does not agree with.
April 30th, 2008 at 5:03:35 PM
Jim: When I saw the headline to your piece, I thought, “Oh, here’s another story about “global warming” that doesn’t get it.
As I’ve written, and as you have so correctly and journalistically, you’ve gotten to the heart of the matter.
“Climate change” not “global warming” will mean not only hotter, but also colder.
Way to write, my colleague.
April 30th, 2008 at 5:09:29 PM
Mendoza had, on personal experience but a grapegrower’s accounting, as I wasn’t keeping strict track, 20 straight days of rain this last Summer season, nothing like that in the historical record. To complement this inversion in historical patterns, Chile has been experiencing severe drought.
Back home in Puerto Rico, the growing sluggisheness of the Gulfstream, as water temperature differentials between the Northern & more tropical Atlantic narrow, aggravate coral bleaching & put the British Isles at risk of harsher Winters…
In terms of the cyclical patterns, it would sem Niño & Niña cycles seem to be more marked, don’t they?
April 30th, 2008 at 6:12:01 PM
Re: Global Warming.
It’s probably better to use the term ‘Weather Change’ rather than global warming. It’s really easy for opponents to point out periods of cold weather, also other strange weather anomalies like monster hurricanes, storms, and say “See?” in an effort to avoid looking at the causes and start working for change.
It’s harder to dismiss ‘global weather changes’.
Real issue: I suspect that a large portion of the ozone layer has been blown off. It seems that the ozone functioned as a ‘buffer’ to stabilize temperature extremes.
That’s been burned off, so we are more vulnerable to wild swings, as we’re seeing in the NAPA CA area.
The whole thing just spells more trouble for wine growers. It’s clear that the grapes need to be protected from not only a) cold weather, but b) hot weather, too hot c) drought, d) wild unpredictable weather.
Spain is trying to adapt to its desertification by planting drought-resistant grapes. We don’t have that option because we don’t know what’s coming.
“Wild-weather grapes?”
April 30th, 2008 at 6:50:44 PM
Thanks everybody for the comments. Just to make it clear, I am calling the phenomenon climate change, not global warming. So, to me, the worst frost season in 40 years (if it does turn out to be that bad) IS further evidence of climate change, because it is exactly the kind of extreme weather event, and in fact a rather mild version of it, that climatologists say accompanies the melting of glaciers in Nepal and the polar ice caps. As I understand it, there is no doubt that this melting is unprecedented over a period of at least 10s of thousands of years. Scientists digging core samples through ancient glaciers can verify this.
As for the effect on wine, it doesn’t take much of a change to modify a region from too-cold for Riesling to just right for Riesling, and from just right for Pinot Noir to hot enough for Cabernet. Of course, a change from just right for Zinfandel to only tolerable for Port might not be the kind of change that most winemakers or drinkers would welcome. I recall Greg Jones lecturing on this at least two years ago: a change in the average temperature during the growing season of just 2 or 3 degrees accomplishes these varietal pushes. And this is huge.
April 30th, 2008 at 8:28:50 PM
Re: grape growers and survival.
You’ve established that the proper term is ‘Climate Change’.
I forgot to mention that there are actually some weather patterns emerging even though a lot of it looks rather random.
Cloud layers – dispersing.
The most recent studies seem to show that the cloud layers are moving away from the Equator, and massing towards the poles (both North & South Poles). This means that countries close to the Equator will have more arid conditions, and countries further north & south will have wetter weather. The rainfall is going to be more massive say around 45 o degrees and up. This seems to confirm what we are seeing.
Vintners would probably benefit from trying to find some types of patterns to the weather changes, if at all possible, rather than randomness.
April 30th, 2008 at 9:31:07 PM
Jim et al.,
Thanks for bringing this issue up and all of the comments that have followed since. While the coldest spring in the last 30 years has occurred and is still continuing, the issues that Jim raises with understanding what climate change is and is not are quite valid. The biggest problem is that most humans base their judgment about many things in their lives, including the weather, on singular events. Most even recall their youth based on single climate events … walking to school in knee deep snow, a flood, a heat wave, etc. Climate change is not a single event like a frost or hail or a severe storm, nor is it a single season or even a couple of years. Climate change is long term and is very hard for humans to get a handle on and fully understand. Like meteorologists, who get chastised for getting the forecast wrong 5 times out of 100 forecasts, climatologists are either mental gods or imbeciles when we forecast climate. As one of the main researchers in climate structure, variability, and change in respect to viticulture and wine production in the world I live in this quagmire all the time. If I give a talk on climate change and it’s just been the warmest week of the year, then hoards come to me after the talk and say “tell me more” … your brilliant! But if I give a talk and it’s just been cool or better yet it’s the middle of the winter and snowing, then hoards come to me after the talk and say you don’t know what your talking about!
Jim and others in the blog are also correct in the assertion that climate and weather extremes are observed to be getting more variable and more frequent, respectively. As a matter of fact, we tend to talk about a ‘normal’ climate, but a normal climate is actually ‘abnormal’ where any given year nearly always deviates from the mean. Therefore we should expect variability in the system. Over the years I have published much on this topic, for the western US and the rest of the wine world. Unfortunately it appears that the delivery of this information to the public, especially the wine industry, is either mis-represented in the media, delayed, or frankly just lost in the academic institutions that create them. I recently published a paper in the journal Climate Research that looked at the specific issues of climate change versus climate variability and the mechanisms that have produced this spring’s weather (I will send it to Jim to see if he can post it somewhere for this blog and others). Basically my research shows that, on average, most wine regions in the western US (European and Australian results are similar) over the last 50+ years have experienced warmer growing seasons, driven mostly by changes in minimum temperatures, with greater heat accumulation, a decline in frost frequency that is most significant in the spring, earlier last spring frosts, later first fall frosts, and longer frost-free periods. However, climate variability does not go away in a warming climate and the mechanisms that have always influenced the west coast are still doing so. Our climate is largely influenced by conditions in the North Pacific and Tropical Pacific oceans which in turn affect the circulation of the atmosphere. Our research on these mechanisms over the last 50-75 years shows that their variability controls our winter and spring predominately, and has important but less significant effects on summer and fall.
The two main mechanisms in the Pacific are sea surface temperatures (SSTs) that drive variations in the Pacific Decadal Oscillation (PDO, North Pacific) and El Nino/La Nina (ENSO, Tropical Pacific). The main difference between the two, besides location, is that the PDO is long term (multi-decadal swings) and ENSO is short term (2-5 years). However, they can and do influence each other. When we examined climate parameters important for wine production (temperatures, frost, degree-days, etc) we found that ENSO variations were not critical, however La Nina conditions were more influential than El Nino conditions. The PDO on the other hand was very influential in west coast wine region climates, where the cold phase produces substantially greater spring frost, later frost events, and cooler growing seasons. The greatest impacts on west coast wine region climates occurred when ENSO was in a La Nina and the PDO was in a cold phase, or where one was in phase with the other (both cold) … exactly the conditions we have been in since late last summer! We also examined vintage ratings (I know it’s not the best variable but sometimes its all you got) for Napa Valley cabernet sauvignon from 1933-2002) (Wine Spectator) and found that cold PDO years with either La Nina or a neutral ENSO (wet ripening periods) produced the lowest rated vintages over the time period.
Back in January and February I spoke about this and wrote about it in different venues (Jim, you might remember my talk at the OWIS) where I said that we should expect a cold, wet spring given how the Pacific was at the time (there is some moderate lead time predictability). Unfortunately, it was even truer than I had thought. Given the current situation in the Pacific it would appear that we are headed to a cooler than average growing season, but a lot depends on whether the La Nina wanes quickly or whether the cold phase of the PDO strengthens like it appears to be doing. The last time we had a strong cold PDO and La Nina conditions in unison were in the mid-1970s when some of the coldest winters and springs in the last 50+ years have occurred. Growing up in Marin then I remember two winters in a row (1976 and 1977) going up to Mt. Baldy (just west of Novato) with my buddies and skiing!
Another issue of concern with climate variability and change is how we and our vines relate to it. When conditions are good (like the last 20 years or so) some of the more marginal landscapes are planted as there is a perception of less risk. Then when frost returns, it impacts these more marginal sites more. I would even venture to say that the damage from this spring’s frosts are likely more pronounced on relatively newer, marginal sites. This would make for a great study! Also, evidence of plant acclimatization to climate change has occurred. In the eastern US and Canadian wine regions one of the biggest limitations has always been winter extreme cold temperatures. For roughly 8-10 years (~1993-2003) many of these regions had mild winters with little freeze impact, then 3 of the last 4 winters brought much colder lows and initial studies show that the losses occurred at higher temperatures than they had in the past.
I am currently in Australia on a fellowship studying climate variability and change impacts here. The Aussies have just been through the 11th year of drought that is strongly tied to ENSO and climate change. The situation is putting major pressure on water for irrigation and has already severely impacted viticultural productivity in many areas. The Aussies see this as harbinger of what to expect in the future and are studying how to best adapt/cope with the changes. As one of the other bloggers wrote about as well, I am continually amazed that the US wine industry is not spending more time and money examining climate issues. But I guess this goes back to the “what is urgent” framework. For the Aussies the eleven year drought is here and impacting them today, it is enough of an issue for them to bring me over to collaborate. For the US a little warming has been good in many respects and there are clearly more pressing needs for research dollars (pests, plant viruses, water management, etc).
I hope this has helped clear up any confusion, but may have created more questions in many cases. Unfortunately, knowledge does not warm a vineyard on a cold spring night.
As I wrote in one of my recent papers on this topic:
“Although climate trends toward generally warmer growing seasons with less frost risk have occurred, this research highlights the impact of climate variability on wine region climates where, should the PDO return to a multi-decadal cold phase, wine growers in the Napa Valley and across the western USA will likely experience greater variability in wine production and quality.”
Regards,
Greg
April 30th, 2008 at 11:33:59 PM
Greg
I am not sure where you source your information but this was not a cold, wet spring in the Napa Valley! The lack of rain was remarkable. We have had less rain and have water restrictions in adjacent counties which I have not seen in my 8 years in the Napa Valley. (Not long, I know but the change and subsequent frost are notable) Our winter rain was remarkably lower than previous years.
As for Australia, in the last 11-15 years as they have suffered drought there has been a much higher incidence of loss from Spring frosts than the previous 20-30 years. The weather results are available. Just look at frost incidence in the Yarra Valley since 1997.
I am not suggesting that climate change is not occurring but frost prediction should have some basis on considering previous seasons drought like conditions. Napa Valley is not in a drought but it is noticeably drier this year.
May 1st, 2008 at 1:14:15 AM
Bella: I think you’re an Aussie, no? Greg Jones is in Australia now but may have been referring more to his home in Oregon when he speaks of recent American weather patterns than of Napa, where I live.
May 1st, 2008 at 1:28:27 AM
Bella,
Jim is correct … a wet, cold winter and spring was in reference to points north (Oregon and Washington). What is interesting is that the La Nina/El Nino influences switch signs at the OR-CA border in terms of rainfall. When EN causes CA to be wetter than normal the PNW from Oregon north is drier. When LA causes CA to be drier than normal, the PNW is wetter than normal. However the PDO does not do this flip-flop, cold springs are cold springs up and down the west coast.
Your comment on frost and drought are spot on … a drier atmosphere allows for lower temperatures. However frosts this year on the west coast were more advection (cold air being brought into the region), not radiation frosts that are more pronounced in dry air. The increase in Australia’s frost the last 10 years of so is about radiation loss at night, not advection of cold air.
My sources are completely valid, its just that I experienced Oregon this winter/spring and did just what I mentioned in the previous post … got caught up in space and time and did not think about the big picture!
Cheers,
Greg
May 1st, 2008 at 11:01:49 AM
Thanks Greg, great information. I stand corrected, el nino/la nina does exist.
So what’s the concensus? Is climate change trending towards more extreme swings or are the two pendulums (PDO and ENSO) just more in sync right now and soon to be back out of sync into what we call “normal”?
May 1st, 2008 at 7:20:23 PM
Brian,
The problem with El Nino/La Nina is that the popular press blew it out of proportion early on blaming nearly everything on El Nino … I’m sure the 49ers slide to the basement in the NFL has been blamed on El Nino somewhere! While the mechanisms and their effects globally are very real, they create broad patterns of wetter/drier, colder/warmer conditions, not individual storms. Also only the largest events in the tropical Pacific tend to have large effects along the west coast.
The latest work from the IPCC shows that extreme swings are more likely in a warmer world. There is also some evidence that ENSO swings may be more frequent today than in the past. The syncing of the two appears somewhat random, or at least what we know today, but may end up being very connected through some other mechanism that we don’t much about.
Cheers,
Greg
May 2nd, 2008 at 10:04:44 PM
I only have observed what is going on in the Napa Valley. We are not seeing the degree of warming claimed by many climatologists. When I compare a couple decades of vineyard based data to the data sets from the local municipal stations they appear to be from completely different regions. It leads me to believe the public temperature data has been contaminated by development. All you have to do is look at what has gone on the last decade around Napa Airport, Napa Hospital, and St. Helena to see why. I think this is why you see local night temperatures increasing so quickly in the last decade. I still freeze my ass off on summer evenings, but if I lean up against the house it is radiating.
1998 was the second warmest year on record in the U.S. (1941 is the warmest), and the local public weather stations provided no indication why we had such a devil of a time getting anything to ripen. I would take surface data with a grain of salt. If you want a good laugh check out the audit going on ISO 2000 weather stations http://www.climateaudit.org/?p=1616
Scroll down and look at the images. Weather stations next to asphalt parking lots with air conditioners blowing on them? It’s hard to imagine the incompetence.
May 18th, 2008 at 3:07:24 AM
When Roger Voss and I were researching WE’s first report on climate change (Sept 2006), Greg’s studies, IPCC reports, and interviews made it clear that 1. extreme was the word to keep in mind 2. winter and spring, not summer, are the seasons that impact agriculture.
How important is climate change? The reinsurance industry (Munich Re, Swiss Re etc.) started studying climate change around 1990 as the first IPCC report was released because, for the world’s largest industry and the financial industries that it encompasses, risk is where it’s at. This year’s tsunamis and oil/biofuel aside, when the world can’t find food because crops are consistently destroyed from extreme heat, cold, drought or invasive pests adapting and migrating faster than the crops can adapt, stable civilization is at risk (to paraphrase Munich Re interview).
While frost damage can cause huge losses for individual producers, the cold may have had a benefit and killed some of the pests that have been ravaging California vineyards. Morton Leslie, Greg, others—any thoughts on that?
(Munich Re’s 2007 stats: http://www.munichre.com/en/press/press_releases/2007/2007_12_27_press_release.aspx)
May 21st, 2008 at 10:15:24 PM
Hello Kathy,
The large swings from a cold and frost impact spring to intense heat in little over three weeks points to what we have been seeing in most of the observations worldwide. Namely that while changes in the averages are what most talk about and debate, for many systems including agribusinesses the more important issues are the extremes. A 1 degF warming over a short period leaves people with a “no big deal” mentality, however the increased variability produces the swings that very evident. Both observations and models show that increased variability in the climate system is seen in warmer periods.
It is relatively easy to build in adaptation strategies and resilience in agribusiness to slow average changes, but difficult to do the same with increased extremes and variability.
Regards,
Greg