So, if I’m reading those graphs right, the best case scenario assuming nothing is done, is a 1 degree rise in temperature by 2050, and in the worst case a 2 degree rise by 2050?
Am I reading them right?
Actually that 2 degree increase best scenario is if we do a concerted effort to limit our emissions. Doing nothing gives us scenarios were that 2 degree Celsius is wishful thinking, and that is is something that really mostly hacks out there are recommending.
And that 1 degree you are talking about early is actually 2. That is 2 degrees centigrade after the start of the industrial revolution. For the last one is indeed 3 degrees, really bad when considering the most likely results.
Ok, so best case scenario if we do nothing is 2 degree rise and worst case is 3 degree rise by 2050?
You have it backwards, doing nothing is 3 degrees, but more likely to be seen at the end of the century, doing a concerted effort to limit our emissions is were we are more likely to see just a 2 degree increase.
AFAICR I have seen papers and reports warning that an increase of 4 degrees could be reached by the end of the century if nothing is done.
ok, thanks for the information!
Actually, the Rotterdam barrier was part of the 50-year plan started after the flood in the 1950s that was catastrophic for NL.
Right as they were finished, they turned around and said “Looking at the evidence, and despite being rather good at Engineering dams, the climate Change meaning both rising sea Levels and more flooding from our rivers, we can’t combat it technologically” and made a new plan:
buy up fields Inland to allow flooding for the rivers,
build some streets on Pontons
build more Floating houses instead of drying dammed land
The Problem is that Engineering works with averages - the 10 year, 100 year and 1000 year flood are based on statistics, and that’s how high you build your dam.
And then weather says “Who cares”*, and you have five 100-year-floods in the same decade, which all go merrily over your dam.
And building a 50m dam instead of a 10m dam not only explodes the cost and introduces whole new Engineering Problems. It’s also a question of how the People living there feel about it, and want that.
If your Population is educated enough to accept reality and that bad weather is too powerful to successfully oppose, the farmers will grumble about giving up the farm of their Family for 300 years, but accept it and relocate.
*Not really, weather isn’t an anthromorphization
This is utter nonsense and needs to be corrected.
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The fact that average temperatures changed over sufficiently long time periods is not relevant here. Global temperature changes in the past were driven by specific natural forcings and typically took tens of thousands to millions of years. The change we are experiencing had most of its effect in the past century, a continuing rate of change that is unnaturally rapid and dangerously destabilizing.
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No, it’s not hard to measure the greenhouse effect, nor does it take “a lot of creativity”. The effect of an increase in any greenhouse gas like CO2 can be ascertained just by plugging in its radiative transfer code.
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No, you don’t “factor out” the effects of water. The water content of the atmosphere directly follows temperature rise because according to the Clausius-Clapeyron relation warmer air hold more water. Water vapor is thus not a climate forcing but one of the important feedbacks of CO2 rise, and one of the most consistent and predictable ones.
To add: from a human (egoistic) standpoint, it’s irrelevant how high CO2 or temperatures were in the past. Nobody is saying that Earth will be destroyed by Climate Change.
It will however be changed so that millions of humans lose their place to live; floodings and draughts and hurricanes will increase; draughts and floodings will cause hunger and thirst, which will lead to even more wars in poor regions over scarce ressources*, Food plants will die out (like chocolate) when the local climate changes; mosquitoes and other insects and with them diseases will spread further North as it’s warming (Italy has insects and animals that used to only live in Northern Africa) and so on.
So People will suffer and die. Many of them. Very rich People can move away from the coast; the poor will stay and drown. Very rich People can buy Food and clean water; poor People will go hungry and drink polluted water. Rich People can buy medicine; poor People will get diseases. And so on.
So Earth and humanity will survive; but People with an ethical code think it’s not okay to let millions of People suffer if we can take easy steps like Switch to solar, wind and water from coal and lessen the Impact.
- we know this from history, where small droughts lead to wars and migrations
And in case anyone read that and thought “but aren’t computer simulations unreliable?” - radiative transfer is not a simulation. It’s just an algorithm that solves a differential equation. For each layer of the atmosphere, some of the radiation that reaches that layer is absorbed and re-emitted, some of it is transmitted. The properties of each layer can be measured in the lab, but calculating the cumulative effect of the whole atmosphere is a tedious calculation best done by a computer program.
Moreover, as the linked Column references, scientists have hundreds of different Simulation models. While they don’t give one outcome, but several, they all Show a trend. It’s not that the models 50% give a “no Problem” outcome and 50% give “gloom and doom”; it’s that they all give “gloom and doom” Scenario, and the only difference is how bad.
Moreover, this has been studied for decades. So the predictions of the models made 20 and 10 years ago can be compared to the acutal measurements from today. And (sadly) they mostly match up. (This can also be used to refine the models for better accuracy and run them again).
We already have global warming. We are already seeing the rise in global temps. We already have the hottest summers since records (which go back over 100 years). We already have over five 100-year floods in my Country in a good decade. We already have more intense hurricanes (more of Level 4 and 5 where previous it was Level 3 and 4) in the US. We are seeing Flora and Fauna changing with the temps. moving northwards, blooming earlier. Of 56 species of migratory birds, only 2 species left my Country in the last winter, the rest had noticed that snow and frost wouldn’t be so bad to spend the effort on the Long flight. (Not People feeding them - observed data of below-zero temps., snow on the ground and frozen ground).
We are already seeing earlier predictions come true. We are also seeing the acceleration mechanisms kicking in: the oceans act as buffer for temperature and CO2, until they suddenly tilt (they also release more water vapour as they warm up, which both increases storms and acts as greenhouse gas).
As Alaska and Siberia Permafrost thaws, not only do houses sink into earth, methane gets released and acts also as greenhouse gas. And so on.
Keeping temps at the current rise of 2 deg. would have been possible; very soon the cycles will kick into self-feedback and then stopping before 6 C is very very hard. And that will be very very bad.
One interesting fact that I like to point out (because of the efforts of others out there that attempt to politicize the issue): equations like that come as the result of work made by scientists like Gilbert Plass in the 1950’s.
http://www.americanscientist.org/issues/feature/2010/1/carbon-dioxide-and-the-climate
Before Plass and others the consensus before the 1960’s was that yes, CO2 and other gases do warm the earth, and while the CO2 was increasing the evidence then pointed at the natural sinks of CO2 to control the issue and the absorption bands of CO2 and other gases were understood enough.
However, almost at the same time, the evidence popped up that the absorption bands were not quite right and that the natural sinks were not doing what was expected. (Cue most of the scientists then thinking: “Oh, S**T!”)
Now, getting back to Plass and the reason to point at his work, Plass and others like him were actually working to make reality and to then improve the new heat seeking missiles being developed, and what was the main reason (looking at how climate was affected was just Plass wondering if the data could be used for climate) to take a look at how heat was being absorbed in different layers of the atmosphere to make better missiles? To shoot down those commie planes during the Korean war.
To me it is an important fact to point out because, sadly, many contrarians out there do launch accusations to the ones doing climate research or the ones proposing changes as being communists, fascists or enemies of freedom. As well as to point out to the contrarians that this is not a new idea.
I accept climate change, and I know nothing of the sort. The IPCC in AR4 predicts a median sea level rise by 2100 of between .28 and .82m, with a median value of .52m.
The difference depends on which model you use for greenhouse gas emissions. None of their models predict a sea level rise of over 1m by 2100. Their highest estimate is .82m, but the likely value is about .52m.
If you want to see the effect of this, the NOAA has a very cool visualization where you can change the height of sea level and see the effect on the US.
Not a single city underwater, even at sea level rises more than double the highest estimate from the IPCC.
In addition, the actual measurements of sea level rise we have seen over the past 100 years have been quite linear, and on the order of 1.6-2.5mm/yr depending on the location. If we simply extrapolate that out for 100 years, that’s a reasonable ‘low end’ for predictions, and it gets us 160-250mm of sea level rise by 2117.
Complicating the issue is that actual measurements of sea level provide conflicting data. For example, here’s a chart of the sea level around Tuvalu, prepared by the Australian Government’s Bureau of Meteorology:
It’s not clear from that chart that there’s a statistically significant increase in sea level at all over the past 20 years, and if there is, the signal is still swamped by annual variance. The standard deviation of sea level height measurements over the period is 0.4766 metres, whereas the predicted sea level rise over that period is maybe .1 meters. That’s a very small signal in a very noisy dataset.
Moreover, the dominant factor in sea level in the South Pacific is the ENSO cycle (El Niño, La Niña). This effect is 40-60 times larger than the annual increase attributed to global warming.
In some areas, sea level may actually go down due to global warming, and in some areas it may go up by much more than the global average. But there is a lot of uncertainty around this - measuring ocean levels on a global basis is extremely difficult, and anyone who says we know exactly what the ocean will do is selling something - whether they are telling you it’s a certain disaster or that it doesn’t exist.
The smart money is on a rise of perhaps half a meter by the end of the century - troublesome, and devastating for some local areas, but on a global basis nearly unnoticeable.
Absolutely nothing that isn’t already happening. And there’s zero evidence that global warming will make Africa uninhabitable.
We have no idea. Ranges for the lifespan of CO2 in the atmosphere vary wildly. This is a major source of uncertainty for future climate change.
Sea walls already protect many cities. Some will have to be built higher. Some cities without them may build them in select areas to protect low-lying real estate and infrastructure. This will be expensive, but it’s not an apocalypse.
As I remember, that was** provided that no acceleration of the loss of cap ice was observed**, and it is now.
As for the claim that no city would be flooded by the end of the century: I did look at the NOAA site and looking at the meter or more that we can expect by the end of the century if we continue as we had, New Orleans and many cities in south Florida look as if more than half of them are flooded. Of course YMMV regarding is that is not enough to talk as if a whole city should considered flooded, but considering what would happen when a huge storm or hurricane comes, a city in that condition would quickly pass into the completely flooded column.
As for the sea walls, I also do think this will not be the end of the world, although some cities are out of luck even with sea walls, but if there are more governments that deny that there is a problem to begin with: then even solutions like that will not be funded for. Or not ready.
A study in 1991looking at how nuclear waste dumps should be marked in a way that was still legible in 10,000 years time considered the Egyptian pyramids as the best tested exemplar of a design that would withstand long-term exposure.
Being of limestone, if climate change included an increase in rain acidity then that would presumably accelerate natural decay, but left to their own devices large stable piles of rocks stay around a long long time.
Sure, if you include Iceland, Greenland, and northern North America in “Europe”. When new Zealand was discovered by Europeans, the Fox and Franz Josef glaciers were almost to the ocean. They were retreating well before western fuel consumption shifted into high gear and started pumping CO2 into the air and causing climate problems in the last 40 years or so. Ditto for the Columbia ice field in the Rockies. Mother Nature has her own agenda and we are just along for the ride - as well as making our own messes.
Perhaps “a little cooler” is only noticeable in more temperate zones.
Plus, there’s the potential feedback issue - warmer air over the oceans, higher humidity, can possibly mean far higher snowfall in the snow-prone winter areas. California and northward is still waiting for this year’s record-breaking snowpack to melt. Depending on whose (skeptic) numbers you believe, some areas of Antarctica are seeing increased snow pack. Also, giant ice shelves that crack off and melt don’t raise ocean levels - they’re already floating. It’s the runoff and glacier bergs from solid ground that we need to worry about.
The implication - Mother Nature is far more complex than any simple computer model. We can’t be sure what’s coming, but it’s stupid not to do what we can to mitigate the problem and at least plan to be ready for the worst.
Another problem is humans. New Orleans, for example, is partly under sea level behind dikes. Any decent surge would be a problem, and heavy pounding won’t help the situation. The delta is disappearing from wave action, but… before human intervention, the river user to regularly flood and deposit replacement soil on the delta. Nowadays, that is channelled farther out to the gulf (building a new, extended delta?) and nothing is replacing what is being washed out by waves since 1900. The problem isn’t rising sea levels, but interfering with natural replenishment.
You were doing so good until the last line. It is the same for many points made by contrarians that then percolate in the media, more often the right wing media.
Rising levels are still a problem even if nature or other human reasons are lowering the height of New Orleans.
So, again, it is good to remember like you said that it is stupid not to prepare for the most likely effects. And one should not ignore that while in some issues there are still uncertainties, like how uncertain extreme weather events such as hurricanes and tornadoes will happen in a warming world. It is really foolish to continue treating our atmosphere like a sewer as if trying to find if those items should be added to the costs that we will have to face in the future just as we will very likely face the more studied ones such as more intense droughts, loss of cap ice, change of weather patterns, ocean rise and acidification.
Actually, as far as I can remember from reading a lot of reports, the increase of some snow packs and the ice in Antarctica was not ignored by most scientists, the issue here is that contrarians cherry pick and just think that concentrating on the few areas the ice is increasing refutes the whole thing. Of course since virtually all serious scientists do not ignore the increase of ice in some areas that should had been a clue that what is going on there is an attempt by some unsavory sources to create FUD about the scientists and their findings.
As mentioned, Antarctica and even Greenland were found to gain ice, but that was mostly inland. The latest reports show that the loss of ice is accelerating for 3 main reasons:
First, concentrating in the polar regions, the studies pointed that indeed a lot of the cap ice (the one not resting over the water) was increasing inland because of the precipitation was mostly ice. But the latest is that the situation is changing and they are seeing more precipitation as plain rain. (One curious bit that comes from that was that Antarctica was called a desert because of the precipitation was not in the liquid form)
Second, It is not only the rain but also the increase of what was seen first in Greenland, the cap ice is showing more lakes of water forming and disappearing, what the evidence is showing is that all that is falling down to lubricate the glaciers and accelerate them leading to a lot of that water to end up in the sea.
And third: As you pointed out, some are ignoring that giant ice shelves that crack off and melt don’t raise ocean levels, but what some ignore is that once a shelve cracks (specially when they are increasing in size and quantity) the ice back in the glacier then moves faster into the ocean. One reason is that wile some expected that hopefully the ice would increase inland the benefit of that vanishes when the ocean is warming and undermining the ice that is just over the ocean and helping accelerate the fall of the ice that was over ground into the ocean.
Yes, but you picked an example were the mistake that was found was to tell the scientists that they grossly underestimated how big the ice loss would become. It is clear to me that one big complicating factor that was not applied properly to the loss of ice models was that the polar amplification of the warming was going to affect the ice in more ways than it was expected.
The point here is that while in other areas the climate predictions were close to what took place, the biggest modeling failure I found on many years of looking at this issue is the underestimation of the loss of ice. Rather than making one become a lukewarmer (an skeptic that assumes that we will experience little change so we should do nothing about our emissions) this bit should make one to realize that it is more likely that many results of unchecked pollution can be worse rather than better.