It's long been known that the IPCC reports tend to be too conservative.
Nevertheless politicians take the numbers for the least dramatic predictions and turn them into promises that they then don't keep.
I guess that it won't be long before some country or other embarks on a unilateral geoengineering experiment. Perhaps when river basins in India start reaching lethal wet-bulb temperatures regularly. Let's just hope that it won't make things worse.
It's not even a thing that needs to be known specific to IPCC - this is a side effect of anything requiring consensus between many people, in this case thousands of scientists (and politicians?). For everyone (or the majority) to agree to sign their name to it, it must deal with the lowest common denominator.
Because the IPCC didn't account for runaway positive feedback loops. So while the rise is slow, it is projected to increase exponentially as more of the Arctic melts: https://upload.wikimedia.org/wikipedia/commons/b/bc/Sea_Leve... which is from a 2017 NOAA study[1].
It's also worth noting that while 3.3mm a year seems low. That is the average, the sea level is not rising evenly across the world. To make this example a bit more real and close to home as HN is mostly US-centric. The current sea level rise is about ~8in/21cm[2], and Miami Beach is already flooding every year. This is because Miami Beach is experiencing almost a 1in of sea-level rise each year according to Hal Wanless, a coastal geologist at the University of Miami[3]. So using NOAA's own maps which show Miami Beach mostly underwater at 3ft we will hit that scenario in about 30 years at current rates[4], but once again sea level rise is not increasing linearly.
> [3] Throughout the record, they found that a combination of two naturally-occurring climate patterns—the El Niño Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO)—were associated with “hot spots” of sea level rise along the Eastern seaboard, including the southeastern hot spot from 2011 to 2015. (...) the Pacific Decadal Oscillation might also be playing a role.
> we will hit that scenario in about 30 years at current rates
What about all the unaccounted negative feedback loops? Like e.g. increased low lying cloud cover formation. A lot of these aren't taken into account by the IPCC either.
> Princeton University researchers have found that the climate models scientists use to project future conditions on our planet underestimate the cooling effect that clouds have on a daily — and even hourly — basis, particularly over land.
However, note that "the researchers found that inaccuracies in accounting for the diurnal, or daily, cloud cycle did not seem to invalidate climate projections, but they did increase the margin of error for a crucial tool scientists use to understand how climate change will affect us."
The links confirm that the clouds are the part of the models. Moreover, from the actual research paper, which compared the models with their data they collected about the DCC (differences during the day, which are less important than the averages) when we parse the text we find:
"the mean appears to be reliable"
"this model tuning does not seem to invalidate climate projections because of the limited DCC response to global warming"
"it may potentially increase the uncertainty"
So the paper can't claim more than weasel wording: "may potentially increase the uncertainty."
It's the averages that are important. It's good that there's the research, but at the moment it still seems it's about the details which don't invalidate anything. Especially it's nothing that can be called
This is already happening. Earlier migrations could be hand-waved away as being due to politics and war, but the current migration crisis in North America is absolutely due to climate change.
The chain of events appears to be climate change -> political instability -> war -> migration -> more political instability.
From what little I know, it seems unlikely that climate change is driving substantial migration into the US. It seems to be mostly about messed up post-colonial political systems, and failed economic policies. Also some local-regional ecological damage, such as deforestation and soil loss. And the War on Drugs, plus training of gang members in the US prison system.
But that will likely change over the next few decades.
> Drought and crop failure in the Central American dry corridor and Climate change in Honduras has been a factor in the formation of the caravans.[17][18][19][20][21][22]
I could understand if the majority of people migrating were farmers, but I haven't seen any statistics that would seem to indicate that is the case. Perhaps some of the migrants are moving because of that but I think there are more factors at play than just crop issues.
It's not just farmers who are effected by crop failures. Loss of crops means an increase in food prices. And when people can't afford food, they tend to take action. What would you do if suddenly, food was either 10x as expensive, or even no longer available in your state? Acute food shortages have been the reality for Mexico & Central Americas for the past decade.
There are many factors at play, but climate change is a a common threat to each of them. Crop failures and loss of arable land cause downstream effects which can result in political instability. Since the food price crisis of 2008, several regions all over the world have erupted in conflict. The Arab Spring was ignited by food shortages. The civil wars in Yemen and Sudan both broke out after severe droughts.
The last Central American migration crisis that the US faced coincided with an El Nino drought in 2014.
The global disaster in that movie was a plausible plot concept. Humanity is already talking about geo-engineering concepts based on aerosols to reflect sunlight. The Snowpiercer universe just kinda took the 'Ice 9' from Vonnegut's "Cat's Cradle" book and used it for geo-engineering.
If we had that kind of technology, we would probably consider it with similar disasterous results.
Technology that impacts the entire planet, wielded by a desperate species, can have disasterous consequences if things go wrong.
Lucky for us, a form of ice that is stable and has a higher melting point isn't a thing in our world...
Us genetically engineering hardy organisms to terraform our way out of the climate crisis is the more plausible 'oops' scenario. All it takes is one project underestimating the results of their work for things to go wildly wrong.
Just based on the url. (After having spent years reading it, I’m not touching Wattsupwiththat anymore)
“Silently slashes”: So silently that the information is easily available everywhere and is published publicly.
“AR5 Final draft”: Yes, it’s shocking that drafts change. It’s almost like the purpose of drafts is for them to be revised multiple times before they are published.
And finally, it’s almost a 100% that the “slashing” happened to get sign offs from political leaders of governments, without which they wouldn’t be able to publish the reports. If anything, this only illustrates exactly why the IPCC reports are far too conservative.
> “Silently slashes”: So silently that the information is easily available everywhere and is published publicly.
On this particular point; organisations do often 'silently' release to the public. For example, Westminster-styled governments are notorious for important things happening on Friday when the press is winding down or legislation never appearing in the talking points.
It is possible to silently do something in the public sphere. Editing draft predictions does sound quite mundane though, they probably weren't trying to slip that under the radar.
> So silently that the information is easily available everywhere and is published publicly.
But "silently" doesn't mean "secretly". It just means that something is done without particular emphasis (maybe because it's not important, or maybe to avoid attracting attention). Note that our perception of the world is shaped more by what we collectively decide to pay attention to, rather than by all the information that is available.
> “AR5 Final draft”: Yes, it’s shocking that drafts change [...] it’s almost a 100% that the “slashing” happened to get sign offs from political leaders of governments.
So you're saying that the IPCC lied in its final draft? But in that case, did we pay attention enough to the fact that the official report was lying? Or we just let it slip silently?
Also, I don't understand how the political leaders could- or would- decide not to sign off a scientific report for predicting further 0.3 degrees of warming per decade. On what grounds?
That says the IPCC revised down their final report from the earlier draft, which accurately described what the models projected. Your article even said they did that revision without consulting the scientists who made the models.
That's entirely consistent with the claim that the IPCC's final reports have been underplaying the actual science, for political reasons.
(Your article is also from five years ago, and still talks about the "missing warming." That was always nonsense, but even hardcore deniers have abandoned that talking point since warming in the last five years has been dramatic.)
IPCC reports are all about getting scientific data acknowledged officially by governments. Of course many of those government officials participating in the process are going to push back against a draft that contains statements that have consequences that inconvenience them on the political field.
That's to be expected. So yeah, when reading an IPCC report it's good to keep in mind that it is going to be conservative.
They are slashing the forecast because global warming looks less bad if we call it 1.5 K instead of 2 K, but they actually did change the baseline instead of their predictions.
At least I guess that is what whattsupwiththat tries to scandalize, unlike the IPCC they are very hard to read, because they don't actually write clearly. (For example, they do not label whether plots are observed data or model output.)
Nevertheless politicians take the numbers for the least dramatic predictions and turn them into promises that they then don't keep.
I guess that it won't be long before some country or other embarks on a unilateral geoengineering experiment. Perhaps when river basins in India start reaching lethal wet-bulb temperatures regularly. Let's just hope that it won't make things worse.