"Drawing on a huge database of climate-recording objects from all over the world—including tree rings, cave formations, and ancient pollen trapped in lake mud—the study concludes that 98 percent of Earth’s surface experienced its hottest period of the past 2,000 years within living memory. That uniform heat spike “is unprecedented over the Common Era,” it says."
In other words, we have used a variety of scientific techniques to fill in the global climate data record.
I'm no expert, but I'm pretty sure we have a good understanding of historical weather based on various natural indicators in the earth's crust. You can read about some of the techniques on NOAA.gov (https://www.ncdc.noaa.gov/news/how-do-scientists-study-ancie...)
Yes. Yes we have. Not only for the last 2000 years. But the 5000 years as well. It might not be in a format we can easily understand. It may not even be accurate compared to today. Agricultural records go back really, really far.
To think that just a few years ago we were hoping to keep the rise in temperature below 2°C. Now it looks like we'll have to deal with temperature increases of up to 5°C.
I seriously doubt that our global civilsation will survive this.
Edit: Hehe, I seem to have hit a nerve here. Or why else the downvotes?
Temperatures high enough to kill people and make agriculture impractical? Rising sea levels that will swallow cities and displace millions? The utter dependence of industrial civilization on the very things that are causing the above?
Besides the points mentioned by sibling comments, there is also the danger of vital ecosystems collapsing. Phytoplankton for example has been on a steady decline, as are insect populations.
I don't quite get the downvotes, seems like a legitimate question to be.
But to answer your question, let spin the scenario I'm currently most worried about.
Let's take for a given that the antrophogenic climate change won't stop at the blue-sky +2°C that everyone is hoping so hard for (hoping, not acting). According to IPCC 2018, we're currently between +0.75 and +1.25°C, with the very real possibility of reaching +2°C by the 2040.
I know! +2°C, that not that much, isn't it! But even at +1°C, we see extreme weather. Huge swaths of India are experiencing drought like /never/ before. Glaciers, the natural water reservoirs in the European Alps, are not growing during the winter anymore. Africa, whose population is expected to continue to grow for another 50 years, is experiencing massive heat waves that threaten to make it's biggest cities inhabitable.
We thought that we had about 30 years to mitigate some of the worst damage. But now - holy shit! - the arctic permafrost is melting, about 70 years earlier than expected. And it's starting to release methane, a way more potent greenhouse gas than CO2. Sure, it rapidly decays in the atmosphere, but not before kicking us to about +4°C. This is the temperature range where some Scientists fear that frozen methane from the ocean floor will start to be released.
Hey, you say, isn't that what happened at the Permian–Triassic extinction event that killed off 96% of all marine species and 70% of terrestrial vertebrate species? Yes, exactly, I reply. But that took about 300'000 years to come to unfold. Not the 200 years we're dealing with.
So, we have a massive temperature increase at an unprecedented speed that makes huge areas of earths most populous regions inhospitable or even inhabitable. Do you think the Syrian refugee crisis was bad? Think about ~1 BILLION PEOPLE on the search for greener (literally) pastures. Do you think they will be welcome with open arms? Yeah, you bet..
Agriculture will be severely impacted. Not only by the heat, but also by the massive die-off that ensues. Because we'll be dealing with a global ecosystem collapse. Most of the animals on earth have a lifecycle that's very closely tuned to the hum of the seasons. At +4°C you can kiss all that goodbye. The only things that will survive are generalist species that have a lifecycle not tied to the seasons. (Cockroaches maybe. Certainly not butterflies. Enjoy them while they last!)
There will also be terrible conflicts and wars about the most precious resource of them all. No, not oil. We'll have oil in barrels, nobody will be lacking oil (at least at first). No, I mean water. We'll have water wars.
This will also be the time that the global economy will start to collapse. War is good for only one business, and that's weapons. Everything else will suffer. Don't expect any deliveries from your Chinese online shop of choice. Consumer markets will crash, everything will come to a standstill.
Now, this is a good moment to have a look at your counter example; the plague that killed almost one third of Europe. You're right; that didn't let civilization collapse, indeed. But you have to understand that back then, about everyone was self-sufficient. You didn't get your electricity from half a continent away. You didn't get your avocados from Peru (you didn't have any avocados, actually...). So while it might be bad that the cobbler doesn't visit anymore (because you really need new shoes), but you can endure that.
How many people nowadays are living in cities with no way whatsoever of supporting themselves for more than four days without electricity? Just make the experiment; you have no electricity anymore for the foreseeable future; how long would your dry rations last? Oh, you don't have any dry rations, everything is in the fridge? Good look then.
So, between collapsing ecosystem, the hunger riots, the wars and the waves of desperate migrants trying to...
I don't really understand the defeatist attitude here. By here I don't mean you, but HN in general this crops up a lot.
Humans as a species have done some pretty impressive things once they put their mind to it. It seems now, not many people care. But once the issue is shoved in everyone's face, and big money cities start sinking, I fully expect a global effort. I can't say with 100% certainty we'll be able to fix it, but I won't say we're done for, either.
The problem is that we need to put our mind to in RIGHT NOW if we want to prevent catastrophic events. It's too late if we start in ten years. Nothing gives the indication that we'll act quickly enough.
I'm not disagreeing, but sadly I feel it may take catastrophic events to get everyone to stop bickering about politics, brexit, reality tv, and all the other trivialities people like to spend their time arguing about.
Logically, to me, if we know what has caused cooling in the past ( whether it's an abundance of some algae, low carbon, or blotting out the sun with ash, I've read all three), we have an idea of what we could try.
"', I fully expect a global effort. I can't say with 100% certainty we'll be able to fix it, but I won't say we're done for, either. "
But by then it's too late. The feedback cycle is measured in decades. It'll keep getting hotter.
of course, it depends what we mean by "too late" Do I really think climate breakdown will cause the extinction of the human race? No, I think some pockets could live on.
I do suspect it could result in a cataclysm greater than any in recorded history, the collapse of civilization, and billions of deaths though.
It's not crazy to think we'll see nukes fly over this. A number of nuclear powers stand to see their countries desertified, and billions of desperate starving people next to now-reasonably-useful land is not a recipe for peace. You think China's just gonna starve and watch Russia in envy?
Or maybe antibiotic resistance will address the root cause at the source.
I desperately hope I'm wrong. But when people like Greta Thunberg say (I paraphrase quite liberally) "Why the fuck should I go to school to learn about grammar when civilization is going to collapse" they kind of have a point.
But these things happen over long periods of time. It's not like China catches on fire and everyone burns to death (tongue in cheek). People get uncomfortable, natural disaster increase, so they migrate. At some point either migration itself becomes an issue, or the last of the poor are tired of being left behind and mass migrate, perhaps violently. So, a collapse is possible, but I think of it as more of a slow lean than a collapse, if it were to happen. And even that would take decades if not centuries. Civilization collapse is inevitable, we know that from the fact a stars life is finite, among other things. That shouldn't prevent anyone from trying to live a happy life, and passing on teachings to the next generation.
Well, I can't say with 100% that we're done for either!
But to me it looks more and more like we really dropped the ball, in a game where you don't get to drop the ball.
We[1] have known about antrophogenic climate change since about 50 years, but for fun and profit decided to deny and lie about it. [2]
Even today we've got "serious business interests" that are actively fighting any attempt to mitigate the damage. Heck, even the President of the United States makes fun about it.
So, I see slim chances for survival (of our global civilisation). Yes, we humans are ingenious, impressive creatures. But we've triggered a cascade that will just keep on going. Now the arctic is burning, releasing frozen methane.
I really hope for your global effort. But I don't see it arriving until it is way too late.
Counterpoint: humans as a species have pretty much always been bad for this planet's biosphere, not just now but for tens of millennia. If you're looking for a species to save us, I'd recommend turning to trees instead :)
What if this is as good as it gets? What if everyone who can be convinced, has been convinced? Will human beings go to their deaths in large numbers continuing to deny something because they can't handle it? I worry that this could be the peak level of responsibility that we as a species can manage.
At this point, it's not a matter of if people will die, but how many people will die. And if millions of people dying is enough to motivate enough people to do something.
We're about to find out if the idea of the 'Great Filter'[0] is true or not.
A lot of people just don't understand why a couple of degrees is a big deal, not understanding that the rate of change we are talking about is vastly different from what our biosphere has experienced in the past.
The increase in the rate of climate change is primarily driven by the increased emission of greenhouse gasses.
The primary driver of increased greenhouse gasses (GHG) is the burning of fossil fuels emitting CO2.
In order to stay below 2°C, we need to remain below 2900 gigatons of CO2 in the atmosphere (source: one of the ipcc reports, I forget which).
Our atmosphere currently has somewhere around 1900 gigatons of CO2, as of 2011. (corrected from earlier error.)
We are currently releasing 35-40 gigatons of CO2 into the atmosphere per year (the US releases about 5), and the rate is currently increasing from year to year.
In order to remain below 2900 gigatons of CO2, we need to reach a GHG emission rate of 0 (zero) overall within the next 7-12 years, through some combination of reduction/elimination of burning fossil fuels, and sequestering of current CO2 from the atmosphere.
Therefore, each person should strive to not only reduce their carbon footprint, but eliminate it and aim for a negative carbon footprint.
And don't think that driving a Tesla will actually reduce carbon footprint ;) Also I am not sure if CO2 is really the most problematic greenhouse gas, I think it's methane. Someone correct me if I am wrong.
Methane is definitely a more potent greenhouse gas, but it doesn't accumulate in the atmosphere for as long as CO2 does, so I wouldn't be so sure about it being more problematic.
I strongly suspect water vapor from con-trails. The tendency to seed cloud formation is well documented, it's a much stronger GHG than CO2, and coincidently air travel has grown right along with total fossil fuel usage. Oh, and the weather forecasters are only recently learning to get it right in the models.
What would you estimate the ratio of total water vapor from contrails is compared with the rest of the atmosphere? And if that's small, why would it be so significant?
In the US, if you want to "make up" for the rest of the world, then since the US releases 5 and the world releases 40, then it means as a citizen maybe you aim for going negative by a factor of 8.
Average carbon footprint of a us citizen is 20 metric tons. The lowest a us citizen can go "naturally" is 8.5 tons, like if you're a homeless person eating in soup kitchens.
To go negative to "make up for the rest of the world" what is that, -140 metric tons? I guess you have to buy carbon offsets. At about $10 / ton, that's $1500 - $1600 / year per US citizen, depending on how much you cut your own emissions naturally.
You could also plant trees, but it takes 40 years for it to absorb a ton. So maybe donate your money and plant 160 trees per year, and then 40 years from now you can stop donating money.
42 comments
[ 4.3 ms ] story [ 105 ms ] thread"Drawing on a huge database of climate-recording objects from all over the world—including tree rings, cave formations, and ancient pollen trapped in lake mud—the study concludes that 98 percent of Earth’s surface experienced its hottest period of the past 2,000 years within living memory. That uniform heat spike “is unprecedented over the Common Era,” it says."
In other words, we have used a variety of scientific techniques to fill in the global climate data record.
NEWS FLASH- the universe is constantly changing and always has been
This is my point. It's not that accurate and to use it as a basis for climate models is ridiculous.
Greenhouse gases have nothing on the aforementioned.
To think that just a few years ago we were hoping to keep the rise in temperature below 2°C. Now it looks like we'll have to deal with temperature increases of up to 5°C.
I seriously doubt that our global civilsation will survive this.
Edit: Hehe, I seem to have hit a nerve here. Or why else the downvotes?
This requires an effort of adaptation but it is no threat to civilisation.
It is not productive to go into hysterics.
The plague killed a third of Europe's population and... No civilisation collapse.
Edit: none of the replies so far describe credible threats to civilisation, so I'm not sure what your definition of "end of civilisation" is
I mean, take your pick.
I suggest reading about https://en.wikipedia.org/wiki/Late_Bronze_Age_collapse
But to answer your question, let spin the scenario I'm currently most worried about.
Let's take for a given that the antrophogenic climate change won't stop at the blue-sky +2°C that everyone is hoping so hard for (hoping, not acting). According to IPCC 2018, we're currently between +0.75 and +1.25°C, with the very real possibility of reaching +2°C by the 2040.
I know! +2°C, that not that much, isn't it! But even at +1°C, we see extreme weather. Huge swaths of India are experiencing drought like /never/ before. Glaciers, the natural water reservoirs in the European Alps, are not growing during the winter anymore. Africa, whose population is expected to continue to grow for another 50 years, is experiencing massive heat waves that threaten to make it's biggest cities inhabitable.
We thought that we had about 30 years to mitigate some of the worst damage. But now - holy shit! - the arctic permafrost is melting, about 70 years earlier than expected. And it's starting to release methane, a way more potent greenhouse gas than CO2. Sure, it rapidly decays in the atmosphere, but not before kicking us to about +4°C. This is the temperature range where some Scientists fear that frozen methane from the ocean floor will start to be released.
Hey, you say, isn't that what happened at the Permian–Triassic extinction event that killed off 96% of all marine species and 70% of terrestrial vertebrate species? Yes, exactly, I reply. But that took about 300'000 years to come to unfold. Not the 200 years we're dealing with.
So, we have a massive temperature increase at an unprecedented speed that makes huge areas of earths most populous regions inhospitable or even inhabitable. Do you think the Syrian refugee crisis was bad? Think about ~1 BILLION PEOPLE on the search for greener (literally) pastures. Do you think they will be welcome with open arms? Yeah, you bet..
Agriculture will be severely impacted. Not only by the heat, but also by the massive die-off that ensues. Because we'll be dealing with a global ecosystem collapse. Most of the animals on earth have a lifecycle that's very closely tuned to the hum of the seasons. At +4°C you can kiss all that goodbye. The only things that will survive are generalist species that have a lifecycle not tied to the seasons. (Cockroaches maybe. Certainly not butterflies. Enjoy them while they last!)
There will also be terrible conflicts and wars about the most precious resource of them all. No, not oil. We'll have oil in barrels, nobody will be lacking oil (at least at first). No, I mean water. We'll have water wars.
This will also be the time that the global economy will start to collapse. War is good for only one business, and that's weapons. Everything else will suffer. Don't expect any deliveries from your Chinese online shop of choice. Consumer markets will crash, everything will come to a standstill.
Now, this is a good moment to have a look at your counter example; the plague that killed almost one third of Europe. You're right; that didn't let civilization collapse, indeed. But you have to understand that back then, about everyone was self-sufficient. You didn't get your electricity from half a continent away. You didn't get your avocados from Peru (you didn't have any avocados, actually...). So while it might be bad that the cobbler doesn't visit anymore (because you really need new shoes), but you can endure that.
How many people nowadays are living in cities with no way whatsoever of supporting themselves for more than four days without electricity? Just make the experiment; you have no electricity anymore for the foreseeable future; how long would your dry rations last? Oh, you don't have any dry rations, everything is in the fridge? Good look then.
So, between collapsing ecosystem, the hunger riots, the wars and the waves of desperate migrants trying to...
Humans as a species have done some pretty impressive things once they put their mind to it. It seems now, not many people care. But once the issue is shoved in everyone's face, and big money cities start sinking, I fully expect a global effort. I can't say with 100% certainty we'll be able to fix it, but I won't say we're done for, either.
Logically, to me, if we know what has caused cooling in the past ( whether it's an abundance of some algae, low carbon, or blotting out the sun with ash, I've read all three), we have an idea of what we could try.
But by then it's too late. The feedback cycle is measured in decades. It'll keep getting hotter.
of course, it depends what we mean by "too late" Do I really think climate breakdown will cause the extinction of the human race? No, I think some pockets could live on.
I do suspect it could result in a cataclysm greater than any in recorded history, the collapse of civilization, and billions of deaths though.
It's not crazy to think we'll see nukes fly over this. A number of nuclear powers stand to see their countries desertified, and billions of desperate starving people next to now-reasonably-useful land is not a recipe for peace. You think China's just gonna starve and watch Russia in envy?
Or maybe antibiotic resistance will address the root cause at the source.
I desperately hope I'm wrong. But when people like Greta Thunberg say (I paraphrase quite liberally) "Why the fuck should I go to school to learn about grammar when civilization is going to collapse" they kind of have a point.
But to me it looks more and more like we really dropped the ball, in a game where you don't get to drop the ball.
We[1] have known about antrophogenic climate change since about 50 years, but for fun and profit decided to deny and lie about it. [2]
Even today we've got "serious business interests" that are actively fighting any attempt to mitigate the damage. Heck, even the President of the United States makes fun about it.
So, I see slim chances for survival (of our global civilisation). Yes, we humans are ingenious, impressive creatures. But we've triggered a cascade that will just keep on going. Now the arctic is burning, releasing frozen methane.
I really hope for your global effort. But I don't see it arriving until it is way too late.
[1] As in: part of humanity [2] https://en.wikipedia.org/wiki/ExxonMobil_climate_change_cont...
At this point, it's not a matter of if people will die, but how many people will die. And if millions of people dying is enough to motivate enough people to do something.
We're about to find out if the idea of the 'Great Filter'[0] is true or not.
[0]https://en.wikipedia.org/wiki/Great_Filter
We didn't listen then, we don't listen today.
A lot of people just don't understand why a couple of degrees is a big deal, not understanding that the rate of change we are talking about is vastly different from what our biosphere has experienced in the past.
The increase in the rate of climate change is primarily driven by the increased emission of greenhouse gasses.
The primary driver of increased greenhouse gasses (GHG) is the burning of fossil fuels emitting CO2.
In order to stay below 2°C, we need to remain below 2900 gigatons of CO2 in the atmosphere (source: one of the ipcc reports, I forget which).
Our atmosphere currently has somewhere around 1900 gigatons of CO2, as of 2011. (corrected from earlier error.)
We are currently releasing 35-40 gigatons of CO2 into the atmosphere per year (the US releases about 5), and the rate is currently increasing from year to year.
In order to remain below 2900 gigatons of CO2, we need to reach a GHG emission rate of 0 (zero) overall within the next 7-12 years, through some combination of reduction/elimination of burning fossil fuels, and sequestering of current CO2 from the atmosphere.
Therefore, each person should strive to not only reduce their carbon footprint, but eliminate it and aim for a negative carbon footprint.
And work like hell to HOLD THEIR POLITICIANS ACCOUNTABLE for creating systems that make it possible to completely ignore it.
Recycling and buying an electric car are great but basically pissing in the wind. A few hippies (myself included) will not fix this.
Average carbon footprint of a us citizen is 20 metric tons. The lowest a us citizen can go "naturally" is 8.5 tons, like if you're a homeless person eating in soup kitchens.
To go negative to "make up for the rest of the world" what is that, -140 metric tons? I guess you have to buy carbon offsets. At about $10 / ton, that's $1500 - $1600 / year per US citizen, depending on how much you cut your own emissions naturally.
You could also plant trees, but it takes 40 years for it to absorb a ton. So maybe donate your money and plant 160 trees per year, and then 40 years from now you can stop donating money.