Just in case it saves one person the effort to research this themselves ... for some reason I find the measurement of climate change in units of temperature a bit problematic (though entirely rational). It tends to suggest the old bugbear of "global warming", which of course gets translated by deniers (& skeptics) into "well it's colder here so that's wrong".
I spent a while digging in to try to get some numbers on a different sense of what's happening. Global average temperature is changing because extra energy is being retained within the boundary of the planet's atmosphere [0]. So how much extra energy is being retained?
A best guess estimate from 2015 would appear to be that
> the earth is getting about 300 terawatt hours of energy per hour due to anthropogenic climate change, and humans use about 16 terawatt hours of energy per hour.
That is, the earth is gaining 18x more energy per hour than we use every hour, thanks to the changes in radiative forcing driven by climate change contributors.
[0] anyone familiar with complex physical systems will understand that when you add energy to such a system, the effects are often hard to predict. It is very likely that the temperature of the system will rise, but you may also see, for example, more movement as well (which is in some sense a related concept to "temperature" but not identical, and it adds uncertainty because it of the extra degrees of freedom).
> anyone familiar with complex physical systems will understand that when you add energy to such a system, the effects are often hard to predict
This is something that is very underappreciated. It's entirely possible that the climate becomes chaotic (in a mathematical sense) and there are sudden, drastic changes that cause economic and social devastation.
It seems inevitable that people will be complacent until it's too late.
On the other hand, this energy can also get converted into complexity. It's not like this hasn't happened before (organisms, trees, animals, cities, etc...). So it's possible with this fast increase in energy, we get the SciFi city we have all been dreaming of.
Of course, it's easier for this energy to dissipate as heat and kill us all.
The thing that blew my mind was that they always report this in degrees Celsius.
I'm in America, even despite an engineering degree, I think in Fahrenheit.
1.5C sounds like a small number, until you remember that Fahrenheit is ~2x 1C.
So 1.5 degrees C is ~3 degrees F. Which, to me, just emotionally feels like a bigger number despite being the same empiraclly.
Similarly, it means when the IPCC is saying there might be a 7C change in 100 years, they mean a 15F change. 15F is emotionally terrifying to me. Its the difference between 85 degrees and 100. 7C is an abstract concept to me.
I wish warnings came with clear outlines of mass extinctions, of changes in resources, and most importantly, of cost to property owners in impacted areas.
That last one could finally cause some action because the current economy largely ignored anything else.
But if any of those outlines don't happen when expected or in a different way then people call it all bunk - same reason people discount it now because of previous dire warnings. The boy who cried wolf is the great fable for this, because ultimately there was a wolf.
"16 terawatt-hours of energy per hour" is simply "16 terawatts of power (continuously)". I want to see writers move away from the unit kWh and instead use joules, which is way less confusing and harder to misuse. Also we as a society need to respect the distinct concepts of energy (J) versus power (J/s = W).
In this place I'm citing from, the writer originally used Joules, but was critiqued by some anonymous commenters and switched. They noted:
> Note: Before anyone complains, I’ve deliberately conflated energy and power above, because the difference doesn’t really matter for my main point. Power is work per unit of time, and is measured in watts; Energy is better expressed in joules, calories, or kilowatt hours (kWh). To be technically correct, I should say that the earth is getting about 300 terawatt hours of energy per hour due to anthropogenic climate change, and humans use about 16 terawatt hours of energy per hour. The ratio is still approximately 18.
Out of interest, you can also convert it to calories. 1kWh is about 0.8 million calories. So, we’re force-feeding the earth about 2 x 1017 (200,000,000,000,000,000) calories every hour. Yikes.
The analogy I've seen which I like is to that of a boiling pot of water on a stove. As you increase the heat (energy) in the system, the water level fluctuates throughout. You have points where there's a higher water level, but you also have points where there's a lower water level.
When we do hit whatever +1.5C or +2C, Q will be 0. The amount of energy input to the earth system isn't changing - that's defined by the temperature of the sun, it's the output that is decreasing.
What your energy look describes is dT/dt, how quickly we will reach the new equilibrium.
At the new equilibrium, the temperature is likely still to be the best descriptor of the new normal - we describe most processes and states in terms of temperatures they happen at, because it's and intensive property rather than an extensive one. You don't have to temper this 300 TW number by the mass or surface area of the earth to get a sense of what's happening when you use temperature
What's the energy number at which a glacier will melt? What's the temperature?
∆T is one of the most important numbers in thermodynamics for good reason
> What your energy look describes is dT/dt, how quickly we will reach the new equilibrium.
The rate is important, but so is the final result. A system whose new equilibrium is +10C is as useless to humanity and life and earth whether we reach it in 25 years or 200.
I agree with you that ∆T is more useful for thinking about actual effects (e.g as you noted glacial melt), but my interest in thinking about it in energy terms is (a) I think it highlights the cause more strongly (YMMV) (b) it better accomodates the possibility of the extra energy in the system having effects not so obviously correlated with ∆T
Yeah, those are interesting numbers. Another one I’m curious about is: how much faster are we burning fossil fuels than they are replenished naturally? The only number I found was a low estimate of 750x, and I think that was for oil. I assume “natural” gas is faster?
Given many fossil fuel deposits took millions of years to settle/decompose/compress, I don't think you get a proper X multiplier without an exponent greater than 6.
Complex systems usually tend to equilibrium otherwise they would be in constant oscillation (positive feedback theory).
As we look back in ice cores, there is variation, but not constant oscillations witch confirm a self stabilizing system.
A few negative feedback we don’t often hear:
increase of co2 have a huge effect on plant grow especially in hash deserted conditions.
Increase in temperature increase humidity: clouds that have a huge effect on reflecting radiation (much greater than co2) increase precipitation, increase plant growth in deserts.
Not to say that we should continue this experiment, but maybe not panic either and see this as the only problem: war, famine, poverty are much more important and real immediate problems instead of projected possible problems.
Im sure the IPCC authors didn't forget their climate science 101 material.
Moreover, we can tackle multiple problems concurrently, no need to make it appear we can only ever do one thing. And as it so happens, climate change tends to correlate extremely well with war and famine. It certainly appears a climate solution is going to help many other big problems along as well.
> clouds that have a huge effect on reflecting radiation
My understanding is that clouds are inside that part of the atmosphere in which radiative forcing has decreased. This means that while they may reflect radiation so that it does not reach the ground, they do not stop (all) the energy from being trapped within the atmosphere.
> war, famine, poverty
All actual problems that will result from significant climate change, not distinct from climate change (even though they may exist for other reasons too).
> increase of co2 have a huge effect on plant grow especially in hash deserted conditions.
Which might sound good for crops but of itself can destabilise ecosystems, African savannahs are already becoming scrubbier with brush and shrubs due to more CO2 enrichment for at least ~1 million and possibly several million years. That will definitely have implications for populations of animals adapted for grassland
The comparisons between the AR5 and AR6 are alarming. Now, under no emission scenarios other than low and very low which we are not tracking close to, we reach +2C at or just before 2050. Many reading this thread will see 3 degrees by the time they plan to retire. This comes with drought, undernourishment, and mass migration: https://sciencenorway.no/climate-climate-change/deadly-heat-...
> Many reading this thread will see 3 degrees by the time they plan to retire. This comes with drought, undernourishment, and mass migration
I wonder what it'll feel like looking back at that point. There isn't anything that I alone can do right now to prevent this from happening, it has to be a collective action but still, we've been warned for decades, over and over, we knew what would happen. Will we regret not having mobilized more, joined every protest out there, not having written our representatives more than we did, not having made more sustainable choices than we did? I know the effect of personal choices and actions is marginal but still, I'm sure we'll feel lots and lots of regret.
Our descendants will rightfully conclude that we were a generation of comfortable cowards. Truly unforgivable. Yet we understandably don't know what to do as individuals. The scale of the tragedy is almost inconceivable.
> I wonder what it'll feel like looking back at that point.
It will feel like nothing, because everyone will have conveniently forgotten about these sorts of reports and predictions when the world stubbornly refuses to end. Just like everyone conveniently forgot that in the 50s and 60s scientists were writing to the US President to tell him that the consensus of scientists was that the world was entering a new ice age, and that he should prepare agriculture and industry for the transition.
I would love to say this comes as a surprise, but it really does not. UN Secretary-General Guterres really foreshadowed that last year, and he did not mince his words. Really unusual for somebody that role, usually it is more of a diplomat-style position.
> Using bogus ‘net-zero’ pledges to cover up massive fossil fuel expansion is reprehensible.
All true, but as a reminder, more energy in a pseudo stable chaotic system means more extremes in both directions: more frequent floods, more frequent extreme snow events, etc., all across the globe.
Do people in capitals not understand or believe this? What do rich people (some of whom control large parts of the media) plan to do exactly? Die? Bunker? I mean seriously.
The problem is to gain political power you have to out compete others for money and votes.
Understanding a problem, and being able to hold on to power while making the hard decisions is a classic unsolved problem in politics.
But it's infinitely harder with very few (two!?!) high centralized litmus-tested groupthink political parties, incentivized to lock up power unilaterally, and marginalize the power of other parties, not skills conducive to governing.
And also infinitely harder with unlimited spending by corporations (who are not citizens, and don't share the interests of citizens), where tiny groups of executives get to leverage all their companies resources toward tilting the political field in their favor, in order to get massive bonuses for feeding insatiable shareholder demand. But without reflecting any of the decency that shareholders might actually have.
It's the moloch beast. The whole system is the problem, but it's near impossible to improve the system's design because it will fight that at every step.
It mindlessly cares about its own survival. Which is how it came to be.
Even if every single person in the system actually wants to do the hard things that will keep the planet in good shape.
What I don't understand is how not even environmentalists seem to believe it given their opposition to nuclear power. If a climate apocalypse were upon us, shouldnt we have been building nuclear power as fast as possible for the past decades? I really don't understand
What are the options, really? Option A is business as usual. Option B is a massive cut in energy consumption.
Option A implies at some point in the future, massive social unrest due to mass migration.
Option B implies massive social unrest today due to a large decline in standard of living. And no, it won’t be the “people in capitals” suffering here.
Option C is option A plus some geoengineering that will likely be undertaken when the situation is desperate enough.
They will be well enough. Maybe their mansions and yacht will be slightly smaller and they will need to find some new destination for tourism. But they will have their air conditioned and heated, homes, cars, shopping centres and so on.
For anyone interested in what 1.5C represents, I can't recommend enough the Climate Fresk [1] exercise.
It's not just the droughts and floods, the heatwaves, the changes in birds, insects, crop yields, … Include permafrost melting and releasing greenhouse gasses, civil unrest in populated areas that won't be livable anymore, unstable food production, and quite a few other causes and consequences.
It's a feedback loop of many moving parts. Thinking that "we will reach an equilibrium eventually" is probably a naïve take. The next natural equilibrium probably includes a decimated world population.
Positive action is necessary now. If you don't know what action to do, go to [1] and start there.
1.5C will be bad, but it won’t directly kill 800+ million people in a short timeframe. People simply don’t respond to harm spread across 100 years the way they react to harm concentrated into a few large events.
1.5C is the (likely to be overshooted) goal. The IPCC report assesses that 2011-2020 is already 1.1C warmer than 1850-1900 (page 7), that the world has been warming by ~0.2C/decade (saw it somewhere), and that current policies (if implemented) will lead to a warming of +3.2C by 2100 (page 23). Page 16 shows various ways in which a +3.2C world will be hostile to humans. For instance most of south and south-east asia, and some of the most populated areas in Western Africa will experience temperatures and humidity levels that are dangerous for human survival >200 days a year. This is now all determined with rather high confidence.
Imagine you live in a valley where elderly people die of heat stroke every summer: 100 three years ago, 500 the summer after, 2,000 last summer. Your parents are 70 and 71 and barely made it. You immigrate, with your children, right? To where? The big city with worse heat management?
Repeat with peasants who can’t grow crops without expensive feedstock, or pig farmers whose water supply is dry. Where will they go?
People will want to flock to places that are currently openly considering tall walls and machine guns to prevent immigration — and that’s when thousands are coming at a time.
You think that having several millions every year will not make that situation a lot more tense?
And underestimating what's actually going to happen, and how difficult it's going to be to reverse, or even put brakes on it is intellectually criminal, but the pro-AGW group hasn't ever cared about that. Why would they, the track record of 'Let industry self-regulate' has worked out great for them in the past.
I'm wondering what those workshops will teach people to do. Most of the advice I hear comes down to three things "Vote green at the polls"(1), "Vote with your wallet"(2) and "encourage others to do the same"(3)
(1) I live in a democracy with ranked choice voting, and I always vote green #1, but the greens are in minority and the main parties are more interested in playing to the masses. sometimes they're in coalition but they don't achieve much.
(2) I'm a relatively well paid person in a relatively wealthy country. I own my own home, and I have rooftop solar installed. But I can't afford an EV that will fit my family, or a heat-pump, so I still have to burn oil or wood to heat the house in winter and burn diesel to bring the kids to school. I die inside a little every time I have to go to a filling station. We live in a rural area with no public transport, so that's not an option either.
(3) I talk people into getting solar panels and switching to EVs, lowering electricity usage, buying second hand, reusing, recycling, every green action thing I can do. I urge people to vote green. Sometimes I feel like I have a little effect here, but I could be fooling myself.
It's disheartening that an environmentally conscious person like myself, with a good steady income and no big debt, still has to burn fossil fuels on a daily basis to keep warm and move around. I feel like I'm part of the problem, not part of the solution.
How would they even predict/model that? Have they modeled all the different plausible crops and agricultural techniques, which regional environmental conditions they're most suited for, and the transitions between them based on regional climate change effects?
It's one thing to model a natural system, but seems quite a bit more complicated to model a system where human technology and decision-making is extremely significant.
> Have they modeled all the different plausible crops and agricultural techniques, which regional environmental conditions they're most suited for, and the transitions between them based on regional climate change effects?
Seems so.
> It's one thing to model a natural system, but seems quite a bit more complicated to model a system where human technology and decision-making is extremely significant.
"Extremely" is a big word. Agricultural yields depend on the weather. A population of 9-10 billion will not be sustained by vertical farms maintained in a synthetic climate.
The problem is that about a quarter of the world population - 2 billion people - currently make their living through traditional small-scale farming. If it turns out that climate change rapidly expands the viable area for growing quinoa, that's great for Peru and Bolivia and the world food market, but it's not going to help a subsistence farmer in Vietnam who finds their rice fields no longer grow enough to live from.
What I always find so hard to believe is that, knowing how well we can predict weather and other complicated systems, climate change science somehow is able to make 1/10 centigrade precision predictions on time horizons of decades and centuries.
If climate models were predicting the temperature of your city on March 21, 2120 then your intuition here would be wise. But that is not at all what these models are predicting. They are predicting global average annual temperatures and other gross, planet-scale statistics.
"Average annual global temperature in a given year" and "temperature in my city tomorrow" are fundamentally very different types of predictions.
Often it is easier to accurately forecast gross dynamics on a long time frame than it is to forecast precise dynamics the exact same process over a short time frame.
You don't even need to understand the math or physics to see why this is intuitively true.
Consider e.g. predicting minutiae about the behavior of a fetus over the next week ("how many fist clenches", "how many kicks") vs. predicting which week the baby will be born -- the latter is substantially easier than the former despite the longer time frame.
Or, more to the point, consider forecasting the position of a particular cloud of molecules in a pot of water being bought to boil vs forecasting the temperature of the water in the pot in 5 minutes. The latter is hilariously trivial -- a small child can be taught how to do this with excellent accuracy. The former is some horrendously difficult phd level fluid mechanics and even then hard/impossible.
In some sense, an educated intuition is exactly the opposite of yours -- it'd be surprising if we were this good at extremely fine-grained weather prediction but couldn't guess the annualized average temperature of the entire system in 50 years. The latter is a much simpler statistic because the timescales and physical scales take a lot of the difficult stochasticity out of the forecasting problem.
Do you also find it hard to believe that casino can say your chance of winning roulette is 1/37 (and you're gonna lose money), despite the fact every roll is random? Both are just law of large numbers.
Compare with how hard it is to exactly predict if a patient is gonna survive the next day-- while assuming that *anyone* (for now) is gonna be dead in 120 years is a pretty safe bet.
And predictions about life expectancy become easier in aggregate, too.
Why would you be confused about this? Temperature of a function of energy. We're talking about a global average temperature. Energy is being captured and retained. That raises the global average temperature. The specifics don't matter.
Predicting the weather on the other hand is very complicated because you're asking what specifically will happen in a specific place. The variables going into that are many and even if measured extremely accurately, it's not good enough because weather is chaotic.
for starters, weather and climate and different concepts. it's easier to predict the long term probability distribution of a coin toss than a single event result.
I see multiple people in this thread are talking about 3 degrees which is unrealistic. While 1.5 seems unlikely at this point 2 degrees is within reach and IMO the most likely outcome. I would even say anything above 2.5 is unrealistic. This chart[1] can be useful, compare it to last predictions and you'll see the reason of my optimism.
Also note in the beginning of 2010s solar was very expensive, right now it's (almost) the cheapest source of energy[2] and the technological problem at this point is battery.
That begin said our problem for switching to renewables isn't only technological, there are political reasons (e.g. China and coal [3]) and also despite solar being cheap for a certain period of time running old infrastructure (e.g. natural gas power plant) still makes economic sense, at least in the short term. but I expect that predictions like [1] become more optimistic in this decade.
As a final note in the past economic growth = more pollution which is simply not the case any more for most of the countries.
As far as I understand implemented policies refers to policies that are currently taking effect (comparable to policies and actions in climateactointracker prediction, the difference between the numbers is probably due to difference in modeling). Lots of NDCs and targets are to be implemented later and there are economic and political intensives to implement them at least to some degree. That's where 2C comes from.
It always makes me sad how scientists have to put on a brave face and try to tell us there's still time. Sadly, they know the most likely outcome puts us blowing past 3C by the end of the century, and 'carbon capture' isn't going to save us.
If you guys are planning to see the natural world in retirement, don't wait. Better to see it as it is now than what it will become.
It's not a brave face. The science tells us that we're on a better and improving track. It's not without hope. A decade ago we thought we were on track for 6C by the end of the century.
That said, it's still going to be worse than we all want it to be. Like many things, the truth lies in the middle and all we can do is push hard on the margins.
No, the entire planet will not become arid desert, don't be silly, but the world will be getting hotter and drier. Coral reefs will bleach. Rain forest will give way to savanna. glaciers will disappear. The world will be irrevocably changed.
I do wish someone would just acknowledge we’ve been getting “final warnings” as well as predictions of catastrophe every few years for decades now. Just recognize that I have to force myself quite hard to take this seriously. I do trust the science! But I trusted the science in 2017 and in 2012 and in 2009 and in 2004 and in 2000 and so on. I am making myself trust the science this time, again, and selfishly I would just like that extra effort validated.
We'll keep getting "final warnings" as we pass "realistic hope of keeping warming under X" and "a sliver of hope for keeping warming under X if a literal miracle occurs" thresholds for different warming levels. The next major report like this will probably have a best-case scenario of more like 2.0C. We're at "a sliver of hope if a literal miracle occurs" for 1.5C (realistic hope of keeping it that low was probably gone a decade ago, and you may have seen that shift reflected in earlier reports) and have passed similar thresholds for 1.0C already.
All I can take from this comment is there are several likelihood thresholds and an array of future Celsius values which can be combined to generate arbitrarily many “final warnings”. Sigh.
The issue is that we crossed those previous thresholds and ... the world kept improving?
If you look at sites like Our World in Data then nearly all metrics of human progress have dramatically improved over the past century, while temperatures increased 1°C.
So it isn't clear that another degree increase will lead to catastrophe. The numbers are round and arbitrary. Our increased wealth and technology has improved lives far, far more than the increased temperature has diminished them, and I don't see why that trend won't continue.
I'm with you on this. And I am absolutely the furthest possible thing from a climate skeptic. If anything, it's just a recognition that this kind of communication from official sources is clearly ineffective. The climate crisis is never ever going to be solved by spontaneous collective action or by appeals to collective action. People will continue to do whatever it is they have to do to get their daily or yearly basic needs met.
What we need are people in positions of power that care.
In a democracy, this means that people in aggregate need to care more about climate change consequences in the future than wealth/disposable income right now.
That is simply a hard sell, always has been, and most of us are to blame for the consequences...
Your comment seems to imply I am a stealth climate change denier of some kind. That is wrong. If you must put me in some category of ignorance, I suppose you could call me a “climate change alarmist ignorer“.
We have been getting warnings like this for years and for years things have been getting visibly worse.
I don't know how you "have to force myself quite hard to take this seriously" when the environment around us has been degrading faster than scientist have been claiming for years.
Maybe you're confused by how events related to climate catastrophe unfold? It's not like a nuclear bomb where one day everything is fine, then the next every thing is gone. That case is different in two major ways: the break down is instantaneous and a new normal is almost immediately established.
The final warning for climate is about a process that once started can no longer be stopped.
You don't have to "trust the science", you can literally watch it happen as the arctic heads rapidly towards a blue ocean event (see "arctic death spiral"), crop failures have been increasing, California has suffered extreme years of drought followed by this current season of incredible floods, lake mead reaches a lower level than it has since it was filled, Texas is subjected to extreme weather (in both directions) causing year after year failure of the power grid.
These things will continue to happen, will happen more frequently and at greater magnitude for the rest of your life.
If you feel unconvinced it's because you're in a state of denial (which in part of grieving so not terribly surprising or uncommon).
I don’t feel unconvinced - which is a good thing, because if I did, the suggestion that it would be because I’m some psychological stage of grief would probably feel patronizing or dismissive.
“the environment around us has been degrading faster than scientist have been claiming for years.”
But not faster than science reporting has been claiming, since they have pretty reliably been claiming apocalypse in 5-10 years for 60 years now.
IMO the situation is that mainstream science said categorically since before 1990 that CO2 emissions lead to unpleasant outcomes, and gives periodic updates on how the world in aggregate is mostly doing worse then planned in emissions and adds some detail to the predicted resulting consequences.
What would you expect from science and science reporting instead?
I lived through the 70s with dire warning of overpopulation and pollution killing us all. It's very difficult to predict the future and scientists has failed miserably in this area. An economist will out-predict a scientist any day.
Let’s say if there is a magical wand that can will any policy the user wants to happen — so the magic can’t remove carbon, but it allows the bearer to pursue any mean within humanity technological abilities — what are the actual actions that could be taken to fight climate change? My impression is that even the big polluter like China (as an example) is already on full speed to build more nuclear plant or solar power, and they just can’t do it faster. Can someone realistically elaborate a high level plan on what could be done, or a pointer to such sources?
80% of the global population lives in a developing nation, keen on quick and dirty energy sources and a growing appetite for hyper consumerism and meat consumption.
The West is living in lala land with some of the proposed policy measures.
A popular one is implenting a carbon tax at the border which forces buyer and seller to internalize societal cost.
But this would result in redefined trading blocs, particularly with united developing nations. The other bloc (paying the border carbon tax) will enter a post-growth period due to slow and expensive trade
Invest on renewable energy, until it is several times larger than our consumption; invest on energy storage and renewable chemical inputs; invest on carbon capture.
There's no hidden trick, all of that is completely obvious. Yet, government action could increase the rate of change several times.
Nobody is in full speed, everywhere things are mostly left to the market, and the market created a huge lot of completely artificial bottlenecks. It also is unable to do research and any kind of long-term investments, even when it's clear those are profitable; and it's always completely unwilling to do infrastructure investment.
this inevitably turns into an argument over the definition of "realistic" that then in turn becomes an argument over hope/positivity-vs-doomer that then inevitably turns into an argument over values.
with that caveat out of the way, here are some examples from other people you can mull around as you ponder the scope and scale.
#2 - Bernie, if elected, wanted to start a 'green new deal' jobs program that would re-direct most of the military budget as well as greatly increase federal spending such that somewhere in the vicinity of 1.5T/year would be spent on the transition. The hope was that in de-escalating our global military presence he could also entice china into a grand bargain that involved them putting more of their military budget into it as well. Again regardless of your opinion on the realisticness of it, its worth recognizing as one of the only people and plans that got the scope and scale correct.
#3 - https://drawdown.org/ Drawdown isn't a policy so much as a menu of options that have been explored, studied, modeled, quantified and ranked.
Simply taxing CO2 emissions and maybe reinvesting some profits (into electrification and renewables) should do just fine.
The problem is people have to pay for these changes. This means potentially:
- General increase in prices/decrease in disposable income
- Danger for competitiveness of domestic industries
- Uncertain second-order effects/additional risk
Just consider electric vehicles-- pushing for no new combustion-car sales starting in 2025 would be political suicide in a lot of democractic nations, simply because people actually value future wellbeing on a planetary scale less than what's in their own pockets right now.
There is absolutely no need to go nuclear for electrical power at this point IMO-- it's not cost competitive, not sustainable and extremely unpopular, too.
Your assessment of nuclear power is completely wrong. Nuclear is the cheapest, most sustainable and widely supported source of clean electricity. Even in Germany more people support nuclear power than oppose it.
There is no way except property seizure and capital reallocation at a large scale. This wont happen, so we're effectively doomed to suffer the slow violence of the inaction of our owners who themselves will never live to feel the harm they're aiding and abetting.
That is a very good point; nothing has done more to solve starvation or improve the global standard of living then capitalism. If we manage a hard switch to another system the mass deaths from starvation and the collapse of the standard of living should greatly reduce carbon emissions.
But removing carbon is within humanities technological abilities. I mean, just plant enough trees, and it's mostly done. This is not even a matter of technology. Removing sources of pollution, like certain animals we use for food and other things is another simple solution, which demands not technology at all.
This problem is not a matter of technology, it's yet another problem of society and people.
One square meter of forest land, if any fallen trees are sequestered in a way so they never rot, will be enough to offset 1 watt of fossil fuel energy use. It's not enough to offset our current civilization by a long shot.
Well, completely deconstruct the globalized civilization we have today for a start. Everything that requires putting carbon into the atmosphere would need to be judged for whether or not it is truly necessary. And if you really want to exhibit wisdom rather than just intelligence, you'd want to start considering how things are going to work if renewables and nuclear simply just don't scale no matter what innovation you try.
The biggest and simplest is build massive nuclear power plants and run carbon capture with the energy. It solves the issue it's just not very $$ efficient.
To start, yes, I agree with all the rest of the comments. Of course if you look at the action needed to start within the 1.5 degree carbon budget, it's simply impossible. It's kind of like saying how much better humanity would be if there were no wars - a nice thought, but also not going to happen.
I'm curious, though, and I admit I haven't read the report, but what is it about 1.5 degrees that the scientific community sees as so critical. Is that the temp after which positive feedback loops take over and it becomes a "runaway train", so to speak (e.g. less ice results in less albedo and more warming, which causes less ice). I just want to understand why that number was chosen to represent such a critical point.
And since it's obvious we are not going to make that limit, what are the additional consequences of hitting 2 or 3 degrees of warming?
Edit: To the downvoters, please take a look at https://ourworldindata.org/co2-emissions. Global CO2 emissions have simply skyrocketed since 1950. The only year they didn't go up was 2020 - remember that year we had a pandemic that shut down much of the world for months and months on end. And still, despite all the stoppage of activity, there was just a small blip down in CO2 emissions. I don't understand how any sane person can look at this graph and believe that 1.5 is attainable. Remember, we don't just have to flatten this graph, we need to bring it all the way back down to 0. I do think alternative energy technology will eventually get us there, but certainly not in 15 years, all across the world.
1.5 degrees is commonly talked about because almost every country on earth pledged to "pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels" [0] in the Paris agreement. We won't hit that anymore, but it makes sense for scientists to compare the taken measures with the original goal. Every degree matters and aiming for 1.5 and missing by 0.5 degrees is better than aiming for a "realistic" 2.5 degrees and missing by 0.2 degrees.
Thanks very much for your response, I think it makes the most sense - that is, 1.5 degrees isn't some "magic number", but every .1 degree makes things disproportionally worse, and we want to limit the damage as much as possible.
In that case, I think still harping on the 1.5 degree number is a communications mistake. It is obviously impossible at this point (see the edit in my original comment), and so I think focusing it risks encouraging a "well, this is obviously too late, might as well enjoy our bread and circuses while they last" attitude. I think it would be much better if scientists said "Remember when we warned you about that 1.5 degree limit? Well, y'all f'd that up, so now a lot of these dire predictions are going to come true. Oh, and here is a whole host of even more dire predictions that will occur for every .1 degree you miss the limit, so you better try to limit carbon emissions as much as you can to prevent things from becoming more screwed than they are already guaranteed to be."
I just think that any messaging that talks about things eventually being "too late" is bad from a public motivation standpoint.
The point wasn't not only hitting that limit, but not hitting it before some date (end of century originally). The planet will continue warming up as long as we have an excess of greenhouse gases, even if we reach some kind of cooked up "net zero" of emissions.
If we warm faster, feedback loops will have more effect earlier, tipping points may be reached in shorter time, biodiversity will drop a lot, and our ability to react and do something about it will be compromised because we will have more urgent things to do like i.e. figuring out new food sources in scale after agriculture becomes unreliable enough.
It is not if we will hit a mark, but how fast we will leave it behind. There is no possible adaptation to fast enough change, for us and the world we depend on.
Thanks for your answer, but to be clear, I understand all that.
My question is what, specifically, the 1.5 degree budget signifies, and why it seems like there will be such a discontinuous amount of harmful effects if we blow past it. What is the significance of 1.5 vs 1 or 3?
Also, I'm not some sort of "climate skeptic" - I totally understand there will be severe negative consequences for continuing to pump carbon into the atmosphere. I'm just genuinely curious on why scientists landed on the 1.5 number.
I suggest watching a Kevin Anderson lecture, basically, the 1.5C and 2C come from the political world, scientists then create research around that to get published, get their research into IPCC reports, etc. It is a farce and purely a political one. They are obsessed with "good news" and "hope".
The assumptions for how 1.5C is "possible" amount to futurism.
The goalposts keep moving too - once it was a 66% chance of staying under 2C, now it's common to talk about exceeding 2C and lowering the temperature later, which is about as plausible as running a car into reverse while the gas pedal is down.
Readit News
I spent a while digging in to try to get some numbers on a different sense of what's happening. Global average temperature is changing because extra energy is being retained within the boundary of the planet's atmosphere [0]. So how much extra energy is being retained?
A best guess estimate from 2015 would appear to be that
> the earth is getting about 300 terawatt hours of energy per hour due to anthropogenic climate change, and humans use about 16 terawatt hours of energy per hour.
That is, the earth is gaining 18x more energy per hour than we use every hour, thanks to the changes in radiative forcing driven by climate change contributors.
[0] anyone familiar with complex physical systems will understand that when you add energy to such a system, the effects are often hard to predict. It is very likely that the temperature of the system will rise, but you may also see, for example, more movement as well (which is in some sense a related concept to "temperature" but not identical, and it adds uncertainty because it of the extra degrees of freedom).
This is something that is very underappreciated. It's entirely possible that the climate becomes chaotic (in a mathematical sense) and there are sudden, drastic changes that cause economic and social devastation.
It seems inevitable that people will be complacent until it's too late.
Of course, it's easier for this energy to dissipate as heat and kill us all.
Ya think ? :)
(no insult intended)
Let's not white-wash the problem.
Now turn up the temperature in your house until it starts moving. You can put it in the oven and crank up the heat if you want
I'm in America, even despite an engineering degree, I think in Fahrenheit.
1.5C sounds like a small number, until you remember that Fahrenheit is ~2x 1C.
So 1.5 degrees C is ~3 degrees F. Which, to me, just emotionally feels like a bigger number despite being the same empiraclly.
Similarly, it means when the IPCC is saying there might be a 7C change in 100 years, they mean a 15F change. 15F is emotionally terrifying to me. Its the difference between 85 degrees and 100. 7C is an abstract concept to me.
That last one could finally cause some action because the current economy largely ignored anything else.
> Note: Before anyone complains, I’ve deliberately conflated energy and power above, because the difference doesn’t really matter for my main point. Power is work per unit of time, and is measured in watts; Energy is better expressed in joules, calories, or kilowatt hours (kWh). To be technically correct, I should say that the earth is getting about 300 terawatt hours of energy per hour due to anthropogenic climate change, and humans use about 16 terawatt hours of energy per hour. The ratio is still approximately 18.
Out of interest, you can also convert it to calories. 1kWh is about 0.8 million calories. So, we’re force-feeding the earth about 2 x 1017 (200,000,000,000,000,000) calories every hour. Yikes.
https://www.easterbrook.ca/steve/2012/01/how-much-extra-ener...
Children sometimes confuse the units of speed and distance, but not when they get older.
Does this imply in preindustrial times the net energy was 0, or is this total energy and there’s some number not mentioned of loss?
What your energy look describes is dT/dt, how quickly we will reach the new equilibrium.
At the new equilibrium, the temperature is likely still to be the best descriptor of the new normal - we describe most processes and states in terms of temperatures they happen at, because it's and intensive property rather than an extensive one. You don't have to temper this 300 TW number by the mass or surface area of the earth to get a sense of what's happening when you use temperature
What's the energy number at which a glacier will melt? What's the temperature?
∆T is one of the most important numbers in thermodynamics for good reason
The rate is important, but so is the final result. A system whose new equilibrium is +10C is as useless to humanity and life and earth whether we reach it in 25 years or 200.
I agree with you that ∆T is more useful for thinking about actual effects (e.g as you noted glacial melt), but my interest in thinking about it in energy terms is (a) I think it highlights the cause more strongly (YMMV) (b) it better accomodates the possibility of the extra energy in the system having effects not so obviously correlated with ∆T
> Earth Overshoot Day marks the date when humanity has used all the biological resources that Earth regenerates during the entire year.
[0]: https://www.overshootday.org/
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As we look back in ice cores, there is variation, but not constant oscillations witch confirm a self stabilizing system.
A few negative feedback we don’t often hear:
increase of co2 have a huge effect on plant grow especially in hash deserted conditions.
Increase in temperature increase humidity: clouds that have a huge effect on reflecting radiation (much greater than co2) increase precipitation, increase plant growth in deserts.
Not to say that we should continue this experiment, but maybe not panic either and see this as the only problem: war, famine, poverty are much more important and real immediate problems instead of projected possible problems.
Water vapor amplifies the effect of other greenhouse gases.
https://climate.nasa.gov/ask-nasa-climate/3143/steamy-relati...
Moreover, we can tackle multiple problems concurrently, no need to make it appear we can only ever do one thing. And as it so happens, climate change tends to correlate extremely well with war and famine. It certainly appears a climate solution is going to help many other big problems along as well.
My understanding is that clouds are inside that part of the atmosphere in which radiative forcing has decreased. This means that while they may reflect radiation so that it does not reach the ground, they do not stop (all) the energy from being trapped within the atmosphere.
> war, famine, poverty
All actual problems that will result from significant climate change, not distinct from climate change (even though they may exist for other reasons too).
Which might sound good for crops but of itself can destabilise ecosystems, African savannahs are already becoming scrubbier with brush and shrubs due to more CO2 enrichment for at least ~1 million and possibly several million years. That will definitely have implications for populations of animals adapted for grassland
I wonder what it'll feel like looking back at that point. There isn't anything that I alone can do right now to prevent this from happening, it has to be a collective action but still, we've been warned for decades, over and over, we knew what would happen. Will we regret not having mobilized more, joined every protest out there, not having written our representatives more than we did, not having made more sustainable choices than we did? I know the effect of personal choices and actions is marginal but still, I'm sure we'll feel lots and lots of regret.
Can YOU Fix Climate Change? https://youtu.be/yiw6_JakZFc
and
We WILL Fix Climate Change! https://youtu.be/LxgMdjyw8uw
Make sure that you watch the second one if you watch the first one.
It will feel like nothing, because everyone will have conveniently forgotten about these sorts of reports and predictions when the world stubbornly refuses to end. Just like everyone conveniently forgot that in the 50s and 60s scientists were writing to the US President to tell him that the consensus of scientists was that the world was entering a new ice age, and that he should prepare agriculture and industry for the transition.
You wait and see.
> Using bogus ‘net-zero’ pledges to cover up massive fossil fuel expansion is reprehensible.
https://en.wiktionary.org/wiki/global_weirding
Understanding a problem, and being able to hold on to power while making the hard decisions is a classic unsolved problem in politics.
But it's infinitely harder with very few (two!?!) high centralized litmus-tested groupthink political parties, incentivized to lock up power unilaterally, and marginalize the power of other parties, not skills conducive to governing.
And also infinitely harder with unlimited spending by corporations (who are not citizens, and don't share the interests of citizens), where tiny groups of executives get to leverage all their companies resources toward tilting the political field in their favor, in order to get massive bonuses for feeding insatiable shareholder demand. But without reflecting any of the decency that shareholders might actually have.
It's the moloch beast. The whole system is the problem, but it's near impossible to improve the system's design because it will fight that at every step.
It mindlessly cares about its own survival. Which is how it came to be.
Even if every single person in the system actually wants to do the hard things that will keep the planet in good shape.
Option A implies at some point in the future, massive social unrest due to mass migration.
Option B implies massive social unrest today due to a large decline in standard of living. And no, it won’t be the “people in capitals” suffering here.
Option C is option A plus some geoengineering that will likely be undertaken when the situation is desperate enough.
Luckily that aligns with the singularity timeline. AGI will have a very good carrot for us to agree on its terms.
It's not just the droughts and floods, the heatwaves, the changes in birds, insects, crop yields, … Include permafrost melting and releasing greenhouse gasses, civil unrest in populated areas that won't be livable anymore, unstable food production, and quite a few other causes and consequences.
It's a feedback loop of many moving parts. Thinking that "we will reach an equilibrium eventually" is probably a naïve take. The next natural equilibrium probably includes a decimated world population.
Positive action is necessary now. If you don't know what action to do, go to [1] and start there.
[1] https://climatefresk.org/
> decimated
1.5C will be bad, but it won’t directly kill 800+ million people in a short timeframe. People simply don’t respond to harm spread across 100 years the way they react to harm concentrated into a few large events.
https://www.ipcc.ch/report/ar6/syr/
1.5C is the (likely to be overshooted) goal. The IPCC report assesses that 2011-2020 is already 1.1C warmer than 1850-1900 (page 7), that the world has been warming by ~0.2C/decade (saw it somewhere), and that current policies (if implemented) will lead to a warming of +3.2C by 2100 (page 23). Page 16 shows various ways in which a +3.2C world will be hostile to humans. For instance most of south and south-east asia, and some of the most populated areas in Western Africa will experience temperatures and humidity levels that are dangerous for human survival >200 days a year. This is now all determined with rather high confidence.
This take is seriously dangerous.
"1.5C is not so bad, chill people"
When the fact is - we don't know the impact - if we go beyond 1.5.
What we do know (because it's already very much measurable) is that much of the worlds glaciers will melt, causing drought.
What we do know is that eventually the sea levels will rise and drown many extremely valuable coastal areas.
Imagine you live in a valley where elderly people die of heat stroke every summer: 100 three years ago, 500 the summer after, 2,000 last summer. Your parents are 70 and 71 and barely made it. You immigrate, with your children, right? To where? The big city with worse heat management?
Repeat with peasants who can’t grow crops without expensive feedstock, or pig farmers whose water supply is dry. Where will they go?
People will want to flock to places that are currently openly considering tall walls and machine guns to prevent immigration — and that’s when thousands are coming at a time.
You think that having several millions every year will not make that situation a lot more tense?
We're going to blow right past 1.5C, 2C, 2.5C...
I'd rather we not find out.
Plan for the worst, hope for the best.
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(1) I live in a democracy with ranked choice voting, and I always vote green #1, but the greens are in minority and the main parties are more interested in playing to the masses. sometimes they're in coalition but they don't achieve much.
(2) I'm a relatively well paid person in a relatively wealthy country. I own my own home, and I have rooftop solar installed. But I can't afford an EV that will fit my family, or a heat-pump, so I still have to burn oil or wood to heat the house in winter and burn diesel to bring the kids to school. I die inside a little every time I have to go to a filling station. We live in a rural area with no public transport, so that's not an option either.
(3) I talk people into getting solar panels and switching to EVs, lowering electricity usage, buying second hand, reusing, recycling, every green action thing I can do. I urge people to vote green. Sometimes I feel like I have a little effect here, but I could be fooling myself.
It's disheartening that an environmentally conscious person like myself, with a good steady income and no big debt, still has to burn fossil fuels on a daily basis to keep warm and move around. I feel like I'm part of the problem, not part of the solution.
Takes 3 hours of your time to find out.
How would they even predict/model that? Have they modeled all the different plausible crops and agricultural techniques, which regional environmental conditions they're most suited for, and the transitions between them based on regional climate change effects?
It's one thing to model a natural system, but seems quite a bit more complicated to model a system where human technology and decision-making is extremely significant.
https://www.ipcc.ch/report/ar6/syr/
> Have they modeled all the different plausible crops and agricultural techniques, which regional environmental conditions they're most suited for, and the transitions between them based on regional climate change effects?
Seems so.
> It's one thing to model a natural system, but seems quite a bit more complicated to model a system where human technology and decision-making is extremely significant.
"Extremely" is a big word. Agricultural yields depend on the weather. A population of 9-10 billion will not be sustained by vertical farms maintained in a synthetic climate.
"Average annual global temperature in a given year" and "temperature in my city tomorrow" are fundamentally very different types of predictions.
Often it is easier to accurately forecast gross dynamics on a long time frame than it is to forecast precise dynamics the exact same process over a short time frame.
You don't even need to understand the math or physics to see why this is intuitively true.
Consider e.g. predicting minutiae about the behavior of a fetus over the next week ("how many fist clenches", "how many kicks") vs. predicting which week the baby will be born -- the latter is substantially easier than the former despite the longer time frame.
Or, more to the point, consider forecasting the position of a particular cloud of molecules in a pot of water being bought to boil vs forecasting the temperature of the water in the pot in 5 minutes. The latter is hilariously trivial -- a small child can be taught how to do this with excellent accuracy. The former is some horrendously difficult phd level fluid mechanics and even then hard/impossible.
In some sense, an educated intuition is exactly the opposite of yours -- it'd be surprising if we were this good at extremely fine-grained weather prediction but couldn't guess the annualized average temperature of the entire system in 50 years. The latter is a much simpler statistic because the timescales and physical scales take a lot of the difficult stochasticity out of the forecasting problem.
Can you predict the average height of all the residents of your city? A demographer can given an answer that is a lot more accurate.
And predictions about life expectancy become easier in aggregate, too.
Source: am data scientist.
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Also note in the beginning of 2010s solar was very expensive, right now it's (almost) the cheapest source of energy[2] and the technological problem at this point is battery.
That begin said our problem for switching to renewables isn't only technological, there are political reasons (e.g. China and coal [3]) and also despite solar being cheap for a certain period of time running old infrastructure (e.g. natural gas power plant) still makes economic sense, at least in the short term. but I expect that predictions like [1] become more optimistic in this decade.
As a final note in the past economic growth = more pollution which is simply not the case any more for most of the countries.
[1]: https://climateactiontracker.org/global/temperatures/ [2]: https://ourworldindata.org/cheap-renewables-growth [3]: https://noahpinion.substack.com/p/china-must-stop-its-coal-i...
If you guys are planning to see the natural world in retirement, don't wait. Better to see it as it is now than what it will become.
That said, it's still going to be worse than we all want it to be. Like many things, the truth lies in the middle and all we can do is push hard on the margins.
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What exactly are you saying here? That in 30 years, the entire planet will be an arid desert?
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If you look at sites like Our World in Data then nearly all metrics of human progress have dramatically improved over the past century, while temperatures increased 1°C.
So it isn't clear that another degree increase will lead to catastrophe. The numbers are round and arbitrary. Our increased wealth and technology has improved lives far, far more than the increased temperature has diminished them, and I don't see why that trend won't continue.
What we need are people in positions of power that care.
That is simply a hard sell, always has been, and most of us are to blame for the consequences...
Okay then - so how do we get those people to materialize?
Absent "appeals to collective action" which you've already determined is never going to work.
- the slow-boiling frog
I don't know how you "have to force myself quite hard to take this seriously" when the environment around us has been degrading faster than scientist have been claiming for years.
Maybe you're confused by how events related to climate catastrophe unfold? It's not like a nuclear bomb where one day everything is fine, then the next every thing is gone. That case is different in two major ways: the break down is instantaneous and a new normal is almost immediately established.
The final warning for climate is about a process that once started can no longer be stopped.
You don't have to "trust the science", you can literally watch it happen as the arctic heads rapidly towards a blue ocean event (see "arctic death spiral"), crop failures have been increasing, California has suffered extreme years of drought followed by this current season of incredible floods, lake mead reaches a lower level than it has since it was filled, Texas is subjected to extreme weather (in both directions) causing year after year failure of the power grid.
These things will continue to happen, will happen more frequently and at greater magnitude for the rest of your life.
If you feel unconvinced it's because you're in a state of denial (which in part of grieving so not terribly surprising or uncommon).
“the environment around us has been degrading faster than scientist have been claiming for years.”
But not faster than science reporting has been claiming, since they have pretty reliably been claiming apocalypse in 5-10 years for 60 years now.
IMO the situation is that mainstream science said categorically since before 1990 that CO2 emissions lead to unpleasant outcomes, and gives periodic updates on how the world in aggregate is mostly doing worse then planned in emissions and adds some detail to the predicted resulting consequences.
What would you expect from science and science reporting instead?
The West is living in lala land with some of the proposed policy measures.
A popular one is implenting a carbon tax at the border which forces buyer and seller to internalize societal cost.
But this would result in redefined trading blocs, particularly with united developing nations. The other bloc (paying the border carbon tax) will enter a post-growth period due to slow and expensive trade
There's no hidden trick, all of that is completely obvious. Yet, government action could increase the rate of change several times.
Nobody is in full speed, everywhere things are mostly left to the market, and the market created a huge lot of completely artificial bottlenecks. It also is unable to do research and any kind of long-term investments, even when it's clear those are profitable; and it's always completely unwilling to do infrastructure investment.
with that caveat out of the way, here are some examples from other people you can mull around as you ponder the scope and scale.
#1 the IPCC themselves. As part of AR6 one of its reports is on mitigation options: https://www.ipcc.ch/report/sixth-assessment-report-working-g...
#2 - Bernie, if elected, wanted to start a 'green new deal' jobs program that would re-direct most of the military budget as well as greatly increase federal spending such that somewhere in the vicinity of 1.5T/year would be spent on the transition. The hope was that in de-escalating our global military presence he could also entice china into a grand bargain that involved them putting more of their military budget into it as well. Again regardless of your opinion on the realisticness of it, its worth recognizing as one of the only people and plans that got the scope and scale correct.
#3 - https://drawdown.org/ Drawdown isn't a policy so much as a menu of options that have been explored, studied, modeled, quantified and ranked.
The problem is people have to pay for these changes. This means potentially:
- General increase in prices/decrease in disposable income
- Danger for competitiveness of domestic industries
- Uncertain second-order effects/additional risk
Just consider electric vehicles-- pushing for no new combustion-car sales starting in 2025 would be political suicide in a lot of democractic nations, simply because people actually value future wellbeing on a planetary scale less than what's in their own pockets right now.
There is absolutely no need to go nuclear for electrical power at this point IMO-- it's not cost competitive, not sustainable and extremely unpopular, too.
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Just like collective farms made Russia and China agricultural power houses.
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This problem is not a matter of technology, it's yet another problem of society and people.
Carbon capture is completely unplausible. Annual US CO2/capita is ~15tons, we simply can't realistically plant enough trees.
Currently there is no way to do anything that would have sufficient effect to compensate current pollution-- we HAVE to reduce it at the source.
But I completely agree that it is mostly just the will that is lacking.
I'm curious, though, and I admit I haven't read the report, but what is it about 1.5 degrees that the scientific community sees as so critical. Is that the temp after which positive feedback loops take over and it becomes a "runaway train", so to speak (e.g. less ice results in less albedo and more warming, which causes less ice). I just want to understand why that number was chosen to represent such a critical point.
And since it's obvious we are not going to make that limit, what are the additional consequences of hitting 2 or 3 degrees of warming?
Edit: To the downvoters, please take a look at https://ourworldindata.org/co2-emissions. Global CO2 emissions have simply skyrocketed since 1950. The only year they didn't go up was 2020 - remember that year we had a pandemic that shut down much of the world for months and months on end. And still, despite all the stoppage of activity, there was just a small blip down in CO2 emissions. I don't understand how any sane person can look at this graph and believe that 1.5 is attainable. Remember, we don't just have to flatten this graph, we need to bring it all the way back down to 0. I do think alternative energy technology will eventually get us there, but certainly not in 15 years, all across the world.
[0] https://unfccc.int/process-and-meetings/the-paris-agreement
In that case, I think still harping on the 1.5 degree number is a communications mistake. It is obviously impossible at this point (see the edit in my original comment), and so I think focusing it risks encouraging a "well, this is obviously too late, might as well enjoy our bread and circuses while they last" attitude. I think it would be much better if scientists said "Remember when we warned you about that 1.5 degree limit? Well, y'all f'd that up, so now a lot of these dire predictions are going to come true. Oh, and here is a whole host of even more dire predictions that will occur for every .1 degree you miss the limit, so you better try to limit carbon emissions as much as you can to prevent things from becoming more screwed than they are already guaranteed to be."
I just think that any messaging that talks about things eventually being "too late" is bad from a public motivation standpoint.
If we warm faster, feedback loops will have more effect earlier, tipping points may be reached in shorter time, biodiversity will drop a lot, and our ability to react and do something about it will be compromised because we will have more urgent things to do like i.e. figuring out new food sources in scale after agriculture becomes unreliable enough.
It is not if we will hit a mark, but how fast we will leave it behind. There is no possible adaptation to fast enough change, for us and the world we depend on.
My question is what, specifically, the 1.5 degree budget signifies, and why it seems like there will be such a discontinuous amount of harmful effects if we blow past it. What is the significance of 1.5 vs 1 or 3?
Also, I'm not some sort of "climate skeptic" - I totally understand there will be severe negative consequences for continuing to pump carbon into the atmosphere. I'm just genuinely curious on why scientists landed on the 1.5 number.
The assumptions for how 1.5C is "possible" amount to futurism.
The goalposts keep moving too - once it was a 66% chance of staying under 2C, now it's common to talk about exceeding 2C and lowering the temperature later, which is about as plausible as running a car into reverse while the gas pedal is down.