I have found that the climate zone mapping is simply getting more granular, more accurate... We have 60-70 year old avocados and citrus in my neighborhood- well beyond the age where a shift in climate would have allowed their success. Especially on hillsides, it has always been free of hard frosts. In the "olden days," the whole County was painted with a broad stroke brush about climate. Look at Napa Valley AVA (circa 1980) for example, and now there are 17 nested AVAs with more on the way. Better mapping is not climate change in and of itself.
Thanks, Steve — I think you’re right that better mapping is revealing what locals like you have known for decades: microclimates matter. Hillsides and pockets that escape frost have always existed — we’re just seeing them more clearly now.
At the same time, we shouldn’t confuse finer data with a lack of broader change. Climate change is real — and it’s the most pressing, existential challenge humanity faces. As global temperatures rise, we risk pushing entire regions past the point of agricultural viability and triggering dangerous feedback loops.
Last year, the global average briefly surpassed 1.5°C above pre-industrial levels — a milestone with wide-ranging implications. That warming isn’t spread evenly, which can make the picture feel murky. But the trend is clear.
Some argue we can just shift farming north, but your example actually shows why it’s not that simple. Microclimates don’t move in straight lines — and neither do the conditions that make agriculture work.
So yes — better maps help us understand what’s possible where. But they don’t erase the broader shift already underway.
Please note I never denied climate change in my comments. Also, weather has much larger swings than climate at this point. Harvest dates vary by as much as a month in adjacent years for example. (The ultimate contrast was 1997 vs 1998.) We had a decade-long drought, now we have had four "average" years, and so on. A few years ago, I forgot when, but the mid-West had massive failures of corn due to lack of rain, this year- floods. Climate is an average... Weather is a rodeo. In fact, the year I was born in 1972 holds the record for highest AND lowest temperatures on Howell Mountain at 110 degrees on July 15th, 1972 and 14 degrees on December 9th, 1972. That was over 50 years ago and to see such extremes then, before our current excitement levels about the climate is something to keep in mind. Again, I am not a climate denier, I simply look at the bigger picture and how we are actually affected.
I first noticed this irregularity in 1990 when the Saint Helena Star used to publish the rainfall data by month for the past 80-something years, I entered it all into Excel and charted it. There are not really average years, lots of variation that mashed up into a mean average gives us our cozy average that we like to talk about.
I have found that the climate zone mapping is simply getting more granular, more accurate... We have 60-70 year old avocados and citrus in my neighborhood- well beyond the age where a shift in climate would have allowed their success. Especially on hillsides, it has always been free of hard frosts. In the "olden days," the whole County was painted with a broad stroke brush about climate. Look at Napa Valley AVA (circa 1980) for example, and now there are 17 nested AVAs with more on the way. Better mapping is not climate change in and of itself.
Thanks, Steve — I think you’re right that better mapping is revealing what locals like you have known for decades: microclimates matter. Hillsides and pockets that escape frost have always existed — we’re just seeing them more clearly now.
At the same time, we shouldn’t confuse finer data with a lack of broader change. Climate change is real — and it’s the most pressing, existential challenge humanity faces. As global temperatures rise, we risk pushing entire regions past the point of agricultural viability and triggering dangerous feedback loops.
Last year, the global average briefly surpassed 1.5°C above pre-industrial levels — a milestone with wide-ranging implications. That warming isn’t spread evenly, which can make the picture feel murky. But the trend is clear.
Some argue we can just shift farming north, but your example actually shows why it’s not that simple. Microclimates don’t move in straight lines — and neither do the conditions that make agriculture work.
So yes — better maps help us understand what’s possible where. But they don’t erase the broader shift already underway.
Please note I never denied climate change in my comments. Also, weather has much larger swings than climate at this point. Harvest dates vary by as much as a month in adjacent years for example. (The ultimate contrast was 1997 vs 1998.) We had a decade-long drought, now we have had four "average" years, and so on. A few years ago, I forgot when, but the mid-West had massive failures of corn due to lack of rain, this year- floods. Climate is an average... Weather is a rodeo. In fact, the year I was born in 1972 holds the record for highest AND lowest temperatures on Howell Mountain at 110 degrees on July 15th, 1972 and 14 degrees on December 9th, 1972. That was over 50 years ago and to see such extremes then, before our current excitement levels about the climate is something to keep in mind. Again, I am not a climate denier, I simply look at the bigger picture and how we are actually affected.
I first noticed this irregularity in 1990 when the Saint Helena Star used to publish the rainfall data by month for the past 80-something years, I entered it all into Excel and charted it. There are not really average years, lots of variation that mashed up into a mean average gives us our cozy average that we like to talk about.
Completely agree. Thank you for sharing.