Climate change is a long-term thing. No single weather event can definitively be tied to it.
This drought is just one event in a long line of documented historical droughts in California. Yes, it's worse than the other ones in recorded history, but we've only been recording for ~200 years so the sample size is small. We can observe further back via tree rings and other creative forensics, but you also have to factor in the different climate. It's not like California didn't have any major droughts before global warming.
Additionally, humans have gutted the only major rainforest in our hemisphere in just the past 30 years. It's entirely possible that the California drought has much more to do with the Amazon being slash-n-burned than due to carbon emissions (although they both contribute to global warming).
A drought isn't climate change. The annual weather is a chaotic system, and a drought for a year or two (or even 10) is normal. Climate change is much longer term.
The problem is timescale, the drought in California was pointed to as an example of a climate change disaster but now it's just about over. Over time the droughts and heatwaves will get worse and worse but human brains aren't geared to think on those timescales.
CA climate has been much drier in the past, even before global warming. We seem to have this discussion every few years when there's a drought, but quickly forget. It seems like we do the same thing with wildfires and earthquakes.
Color me a little skeptical - but I remember a big noise about how the drought that california was intensified by climate change.. I mean I guess its possible that the drought and increased rainfall are caused by the same thing.
What's the evidence for the link between west coast droughts in recent years and global warming? (I'm not trying to start a debate, just genuinely asking).
Yes, but this is the same argument people make about how you can’t attribute a given hurricane to Climate Change (although science has becoming more capable of those kinds of attributions in recent years).
Yes, climate fluctuates. Yes, there have plausibly been years of drought and fire in centuries past that would rival recent years. But absent the specific data you say is lacking, if you believe that climate science is generally correct, then more drought, more warming, more fire is the obvious trend. Not just California, but the entire world.
Regardless of whether similar events have happened in the past, there’s an obvious reason for the dramatic uptick between the 1970s and today: CO2 in the atmosphere, put there by humans.
I'm not saying that a drought is evidence of climate change - I'm saying the opposite.
The article ties climate change into this, when it says:
> According to experts, the dry season has worsened this year due to El Niño, an irregular climate pattern over the Pacific Ocean that disrupts normal weather, adding to the effect of climate change.
but there is no reason to think climate change has anything to do with this. The article itself also says:
> The rock carvings are not usually visible because they are covered by the waters of the Negro River, whose flow recorded its lowest level in 121 years last week.
ie 121 years ago, the river was recorded as being this low. ie before climate change.
For me this is another 'climate change' article, but is interesting as not all the claims the article makes can all be true.
It's hard to say what will happen here. If the drought subsides, which statistically speaking it should as California's climate trend should "regress to the mean," the ecosystem should recover to some extent. Unless the tree population/ecosystem has been so grossly devastated that the tree it is past returning to a self sustaining point.
The current drought in California isn't widely considered to be caused by global warming though there does seem to be some notion that it has been worsened by it. It's too sharp a climate swing to fall along the global warming trend line.
The scary thing isn't that this is global warming but that this is just an image of what rapid climate change could do on a much vaster scale if not kept in check somehow.
This bad take comes up all the time and I try to educate people every time it pops up:
> California is getting hotter and dryer with the climate catastrophe
California in the 20th century was very abnormally wet and mild. Using scientific data and looking back 2000+ years one gets a picture of centuries long droughts, and of extreme weather as very normal. This is the status quo and the past 100 years of mild and wet climate is the weird abnormality(which people think it always should be like).
Citation please? I am skeptical that 'scientists' monolithically predicted 100 years of drought due to climate change. I never recall reading such a thing in years of news coverage.
As a layperson, I always assumed that most weather we experience is in line with historical variability. Climate change causes (or is) small changes in the bias and variance of this weather. Saying that some of the drought is caused by natural variability and some of drought was exacerbated by GHG-induced warming seems like a perfectly consistent and reasonable position.
I don’t want understate the impact of climate change, but if the author is comparing the dryness of 2021 specifically to 1993… 1993 was the 5th wettest year in California since the 1930s, and 2021 is a drought year.
Ah, in that case, here's my understanding, in brief. There are several components:
1. California has had multi-hundred-year drought cycles in the past, according to tree ring data, and the last several hundred years have been unusually wet by comparison. It's possible that we're re-entering a long period of overall drought. (e.g. http://www.nytimes.com/2015/04/14/science/californias-histor...)
2. The current drought has been exacerbated primarily by a pattern of high and low pressure systems over the arctic, the polar vortex system. The newer "curvy" shape of the polar vortex is leading to systems which are keeping cold fronts from descending into the west coast.
3. The current working theory is that the shape of the polar vortex is influenced mostly by the temperature of the arctic, so it's not likely to return to what we thought of as normal until the arctic starts to cool down again, which might not be happening anytime soon. (e.g. https://en.wikipedia.org/wiki/Polar_vortex#Climate_change -- sorry for Wikipedia link.)
4. There has been a gradual decrease in snowfall over the Rockies and, I think, the Cascades region. (e.g. https://www.ncdc.noaa.gov/sotc/drought/201502, http://usatoday30.usatoday.com/weather/news/2011-06-10-clima...) A lab in Berkeley is responsible for measuring snow pack in the Sierra, and they have some data going back to the late 19th century. Unfortunately, all I can find are graphs of their data, not their actual data, so I have to contact them and see if they're willing to share that so I can see how the average is changing. My hunch -- although it's only a hunch at this point -- is that I'll find a slight overall decline in average snowfall, same as there is in the Rockies and Cascades. Seeing if this data is available is part of what's holding up a more comprehensive reply.
I have links to articles for most (all?) of this, but ... it's a little bit discombobulated still. I think it really needs to be presented more coherently to look very convincing. Part of the reason that I'm reluctant to start sharing links right away is that some of the sources I have at the moment are crappy little blogs -- thank you very much Google -- and I have to take the graphs they've ripped off and try to locate the primary sources they ripped them off from and then read them and make sure the context is correct and all that.
I'm not a meteorologist or climate scientist, it's likely there are areas that I'm oversimplifying or misunderstanding. But, I am an avid reader, and I haven't come across much material that's painting an optimistic view of California's climate in the near future.
>Hurricanes have obliterated parts of the Gulf Coast, dumping more than 50in of rain in some places.
This is not evidence of climate change, and if you go and read NOAA's and the IPCC's own data they show that there has been no significant change in the frequency or intensity of hurricanes, and any minor change is actually a decrease in frequency of the last 50 years.
>Wildfires have denuded the California wilderness and destroyed thousands of homes.
Forest fires are also not a climate change event but rather a natural occurrence that was made all the worse by California's/DNR/USDA policy not to let these burns happen more frequently and allowing the build up of dying or dead material that burns much easier and makes life harder in forest areas in the state, something that the Forest Service has admitted.
https://www.fs.usda.gov/detail/sierra/landmanagement/?cid=st...
>A once-in-a-millennium drought has dried up rivers and forced farmers to stop planting crops.
A once in a millennium drought would suggest that this has happened before and is not necessarily the result of any changing climate. Beyond that, how do we know that this is a once in a millennium drought? I'm no geologist, but I do know that weather records have only existed for the last approx. 150 years, during which I think water distribution of the Colorado river was meted out during years of very high rainfall, etc. that caused baselines to be determined incorrectly.
>In cities like Miami and Norfolk, where sea levels are rising
Again, NOAA's own data shows that while seal levels might be considered rising, they are doing so on average of less than a foot per 100 years, and that's often with only 50-100 years of data. This is not necessarily evidence of climate changing because over the next 100 years this could go the other way and average out.
https://tidesandcurrents.noaa.gov/sltrends/mslUSTrendsTable....
For an article that makes large assumptions on the movement trends, primarily of Californians, the author does little in the way of providing data to back up the claims.
Recent human experience. Local climates were never in steady-states during human experience. California is a great example: during the industrial age it's been in an unusually wet period.
> Drought is intrinsic to the natural climate of California.[6] Across the Californian region, paleoclimate records dating back more than 1,000 years show more significant dry periods compared to the latest century. Ancient data reveals two mega-droughts that endured for well over a century, one lasting 220 years and one for 140 years. The 20th century was fraught with numerous droughts, yet this era could be considered relatively "wet" compared against an expansive 3,500 year history. In recent times, droughts lasting five to 10 years have raised concern, but are not anomalous. Rather, decade long droughts are an ordinary feature of the state's innate climate. Based on scientific evidence, dry spells as severe as the mega-droughts detected from the distant past are likely to recur, even in absence of anthropogenic climate change.
This drought is just one event in a long line of documented historical droughts in California. Yes, it's worse than the other ones in recorded history, but we've only been recording for ~200 years so the sample size is small. We can observe further back via tree rings and other creative forensics, but you also have to factor in the different climate. It's not like California didn't have any major droughts before global warming.
Additionally, humans have gutted the only major rainforest in our hemisphere in just the past 30 years. It's entirely possible that the California drought has much more to do with the Amazon being slash-n-burned than due to carbon emissions (although they both contribute to global warming).
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