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".<p>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?<p>A best guess estimate from 2015 would appear to be that<p>> 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.<p>That is, the earth is <i>gaining 18x more energy per hour than we use every hour</i>, thanks to the changes in radiative forcing driven by climate change contributors.<p>[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).
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: <a href="https://sciencenorway.no/climate-climate-change/deadly-heat-and-extreme-rainfall-this-is-what-the-world-will-be-like-if-the-temperature-rises-by-3-degrees-according-to-researchers/1950125" rel="nofollow">https://sciencenorway.no/climate-climate-change/deadly-heat-...</a>
For anyone interested in what 1.5C represents, I can't recommend enough the Climate Fresk [1] exercise.<p>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.<p>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.<p>Positive action is necessary now. If you don't know what action to do, go to [1] and start there.<p>[1] <a href="https://climatefresk.org/" rel="nofollow">https://climatefresk.org/</a>
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.<p>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.<p>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.<p>As a final note in the past economic growth = more pollution which is simply not the case any more for most of the countries.<p>[1]: <a href="https://climateactiontracker.org/global/temperatures/" rel="nofollow">https://climateactiontracker.org/global/temperatures/</a>
[2]: <a href="https://ourworldindata.org/cheap-renewables-growth">https://ourworldindata.org/cheap-renewables-growth</a>
[3]: <a href="https://noahpinion.substack.com/p/china-must-stop-its-coal-industry" rel="nofollow">https://noahpinion.substack.com/p/china-must-stop-its-coal-i...</a>
It always makes me sad how scientists have to put on a brave face and try to tell us there's <i>still time</i>. 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.<p>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.
I do wish someone would just <i>acknowledge</i> we’ve been getting “final warnings” as well as predictions of catastrophe every few years for decades now. Just <i>recognize</i> 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, <i>again</i>, and selfishly I would just like that extra effort validated.
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?
To start, yes, I agree with all the rest of the comments. <i>Of course</i> 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.<p>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.<p>And since it's obvious we are <i>not</i> going to make that limit, what are the additional consequences of hitting 2 or 3 degrees of warming?<p>Edit: To the downvoters, please take a look at <a href="https://ourworldindata.org/co2-emissions">https://ourworldindata.org/co2-emissions</a>. 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 <i>still</i>, 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 <i>do</i> think alternative energy technology will eventually get us there, but certainly not in 15 years, all across the world.
It's the "final warning" in the sense that the next report is going to be issued in 2030. By that time, 1.5C will be be inevitable. We may not have hit the temperature yet, but only because it takes a few years for the temperature to respond to the greenhouse gases already in the atmosphere.<p>Which is to say, if we don't change right now, then when the next report comes out, we will already have enough CO2 in the atmosphere to be at 1.5C -- even if we stopped burning fossil fuels absolutely and utterly.<p>I'm really not sure how much such a warning can accomplish, after decades of having been ignored in the past. I've been treating 1.5C as a fait accompli already.<p>The problem for me is less about the actual temperature, or even the disasters that will come of it, but what it does to American culture right now. The whole world has failed to solve the problem, but I think America was the lynchpin. We deny that the problem exists, making it much harder for the rest of the world to summon the will to spend money to do it.<p>But in America, that has cost us our relationship to science. Any HN discussion is sure to be filled with criticisms of the scientists, many of them insisting now that this is all some kind of leftist power trip. That has utterly destroyed not just our ability to use science for any national ends, but an implacable, violent hostility between political groups.<p>Climate change is only one part of that culture war, but it is a particularly strong example. The climate conspiracy theorists are simply wrong, just plain factually on the face of it. It's not a matter of values, or interpretation, or conflicting scientific models. There's a right and a wrong answer, and if even that turns to bitter hatred, how an we possibly resolve any genuine differences of opinion?
Final report, not final warning - that's the guardian's headline spin, the 'warning' comes from a "climate expert at Greenpeace International" in the article.<p>"The Synthesis Report will be the last of the AR6 products and is scheduled to be released in March 2023 to inform the 2023 Global Stocktake under the United Nations Framework Convention on Climate Change."
Assume we hit 1.5C and "nothing happens" does this help the cause?<p>While I'm very concerned about how unchecked climate change could impact future crop yields I also worry that having a hard line like this probably won't help convince anyone, and could counter intuitively act as a "I told you so" for climate denialists when the world doesn't fall apart as soon as we hit 1.5C.<p>A lot of the more convincing arguments I hear from climate denialists (I hate that phase btw) is that past climate models have been highly inaccurate and many claims and concerns have in time been proven overstated. This is somewhat true.<p>But here we are once again looking down on the masses and effectively saying, "you plebs just don't get it, this is your final warning before you all die".<p>I think I'd rather the data was presented with less emotion and I think that would be more convincing personally, but at the same time I suspect we're probably going to have to see some dire consequences of climate change before any serious action is taken.
Is it just my memory playing tricks, or did we not use to talk about crossing the 1C threshold? I guess now that that’s not a possibility anymore, we’re moving to the next, hoping to get some sort of action out of politicians.<p>I strongly suspect we’re going to cross the 2C threshold in our lifetimes.<p>The willpower to change things isn’t there, and the effects are too far removed from our decisions. Even the floods and droughts are easy to ignore, telling yourself “it’s not happening here, just some random far away place”.<p>But I also think that we’ll slowly start reducing our emissions anyway, as electric cars and green energy keep spreading. So we will eventually reach an equilibrium. I just don’t think that that’ll be before the 2C threshold.
A major addition to this report compared to previous ones was the emphasis on "demand side" mitigations. That means scaling down excess energy use in a way that doesn't compromise people's quality of life.<p>For example this paper suggests that in the UK a reduction of 52% by 2050 compared with 2020 levels is possible.<p><a href="https://www.nature.com/articles/s41560-022-01057-y" rel="nofollow">https://www.nature.com/articles/s41560-022-01057-y</a>
Looking at the CO2 concentration per year chart: how long until we've got Spaceballs' "Perri Air" to avoid cognitive impairment? Anyone already experimenting with getting their indoor air closer to the (extrapolating a bit) ~250-280PPM of the pre-industrial atmosphere? This'd be a step farther than people who vent in outdoor air to keep indoor air from creeping even higher due to respiration and such.
Average corp still don't care! 1.5C is just a number. Until we <i>witness</i> cities with populations over 1 million <i>destroyed</i> by climate change, warnings will continue to be (largely) ignored. Yes, it will take <i>that much destruction</i> before we collectively get our shit together and force ourselves to stop burning fossil fuels.
Tragically, they're wasting their time. Experience has shown that such IPCC preaching is like telling the world to stop using Facebook and Google because tech giants spy on users and sell their data.<p>Everyone knows that and most don't like it but their addiction is too great to make the necessary lifestyle changes to quit.
So, does this apply to China, which is burning more coal than ever?<p>The UN secretary general, António Guterres, said: “This report is a clarion call to massively fast-track climate efforts by every country and every sector and on every timeframe. Our world needs climate action on all fronts: everything, everywhere, all at once.”
The problem is to a large part one of attack surface, if we don't have anything to talk about we talk about weather because weather effects everything and everyone. Thing is, all our systems are tuned to how the weather is right now, if climate and thus weather changes, problems can potentially pop up just about everywhere. Now we can talk about the systems we know are at a critical location, like coral reefs, but the actual problem is about unknown unknowns: Right now we are taking the bet that the worst problem connected to a changing climate that nobody has thought about is quite bearable, which to me doesn't look like a good bet.
The currently measured temps are nowhere near reality. We're already way past 1.5ºC if we consider aerosols cooling, climate lag, and feedbacks. We've already eaten and really just waiting for the bill. Even if a miracle happened today and we reached zero emissions it wouldn't change that.<p>But considering that our global emissions are huge and population keeps growing I'd be very surprised if we didn't reach 2ºC in a couple of decades. Even with the efforts of some countries in reducing emissions, our per capita global emissions have been hovering between 4-5t since the 70s and we're probably going the break past 5t in the next years.<p><a href="https://ourworldindata.org/grapher/co-emissions-per-capita?tab=chart&time=1916..latest">https://ourworldindata.org/grapher/co-emissions-per-capita?t...</a><p>The only way out of this are very strong negative emissions. That is, reducing emissions and removing carbon from the atmosphere.
> as rising greenhouse gas emissions push the world to the brink of irrevocable damage that only swift and drastic action can avert.<p>Well like no one knew that :) But the official report I am sure details all the background to prove that statement. It is too bad the people that can do something will not only ignore the report but probably will double down.
Well, some weeks ago The Guardian wrote:<p>Early forecasts suggest El Niño will return later in 2023, exacerbating extreme weather around the globe and making it “very likely” the world will exceed 1.5C of warming. The hottest year in recorded history, 2016, was driven by a major El Niño.<p>1.5°C is basically already locked in.<p><a href="https://www.theguardian.com/environment/2023/jan/16/return-of-el-nino-will-cause-off-the-chart-temperature-rise-climate-crisis" rel="nofollow">https://www.theguardian.com/environment/2023/jan/16/return-o...</a>
Are there any resources that show the improvement we've already made in those terms? I think that would be helpful. Like, there's got to be an estimate of what our rate was when growth was before we started introducing what we've already been doing. I know there are cynics who want to make the argument that we've done absolutely nothing and that we're still in the base scenario, but I think that doesn't give credit to the advancements we've made due to environmentally-influenced policy changes across the world.
For a counterpoint, I thought wattsupwiththat's analysis was alright. But I'm not qualified enough to make a definitive judgment. Can somebody better informed tell me if this article is complete bull?<p><a href="https://wattsupwiththat.com/2023/03/15/climate-crisis-what-climate-crisis-part-one-the-evidence/" rel="nofollow">https://wattsupwiththat.com/2023/03/15/climate-crisis-what-c...</a>
Just looking at the press conference slides, some notable stuff in there. "The challeng ... Cut global GHG emissions by nearly half by 2030." I don't know why they bother putting that in there, it is obviously not going to happen. We will be lucky if by 2030 the emissions are below the current level...
"There is a rapidly closing window of opportunity to secure a liveable and sustainable future for all (very high confidence)"<p>Given how each word is carefully weighted in their report, this sounds a bit scary to me.
AI, Climate Change and war in Ukraine.<p>It's really getting harder to stay sane and calm.<p>If we all end up being replaced by AI, I can't see the devastating economic effects being good for the move to renewables.
What's the goal of these warnings? If the right people cared about global warming and pollution, they could implement a simple law, at least in the US and EU: every item sold must be imprinted with a manufacturer id that's responsible for properly disposing this item. Coca-Cola would go bankrupt, but the amount of plastic trash in the ocean will be halved. Most consumer goods will double in price, because disposing a broken washing machine is not a small feat. The unhinged consumerism will end, but with it will end the economy as we know it.
This whole "act now or it will be too late", I think actually damages our chances of dealing with this.<p>The reason is that there is a good chance we will blow past 1.5, and this will be brought up as evidence that they are just "crying wolf".<p>My guess is that the "final warning" phrasing is more news media and not actual scientists. If so, the news media is doing a great disservice to humanity.
My comment was removed because it doesn’t support the current orthodoxy. (and could make people feel bad about their new climate religion)<p>I would be great if the censure applied here would put the comments censored on another page with a link to it.<p>That way people interested could see what is removed and why. Instead of being it silent and hidden.<p>More and more I feel that HN has become an echo chamber where only one direction is allowed.<p>TLDR: make censure explicit and visible instead of hidden.
TL;DR - Sorry for this long post.<p>"Scientists have issued a "final warning" on the climate crisis as rising greenhouse gas emissions bring the world to the brink of irreversible damage that can only be averted by swift and drastic action."<p>OMG.<p>I just stopped reading after the first paragraph. Welcome to the attention economy where only the biggest fairground screamer gets a hearing. Except that fairground screamers are definitely not part of the achievements of "age of enlightenment".<p>I remember a few years ago - when it was about the populism of extreme right-wing parties - how the propaganda was described: First a problem is described as a catastrophe, and then the only way to solve it is presented. Any parallels?<p>Nothing - but absolutely nothing - makes sense in this paragraph. Where is the critical thinking that "science" always prides itself?<p>It starts with the fact that scientists have issued a final warning on the climate crisis. Sounds somehow like parents who are at their wits' end with their educational measures and don't know what to do next. And what does "final warning" actually mean? Will we be spared that from next year on? Or will there be the "really last warning", the "last last warning" or the "last last warning 2"?<p>I am sure they will continue with their "warnings" next year. What else are they supposed to do?<p>So then the world comes to the brink of irrevocable damage? What is that supposed to be? Irreversible damage like the last eruption of Eyjafjallajökull in 2010, the irreversible damage of the Hiroshima bombs, the irreversible damage of the last world war?<p>The world is continuously changing. Things are destroyed and things are rebuilt. We dig up the earth everywhere we greed for mineral resources. For the next iPhone of the very scientists who warn against it. We changed the surface of the Earth a dozen times but now it's irreversible. Fun fact: If nature gets the chance in 1.000 years nothing will be there anymore because nature irreversible changed everything again. Is this a catastrophe as well?<p>But it's not even "damage", it's just the "brink of possible damage". So we are heading for a situation that might produce damage - and that we can only prevent by taking drastic measures.<p>But who tells us that precisely these drastic measures will not also lead to damage?<p>Yes, the climate is changing. The glaciers are melting and suddenly old Roman roads appear that led over the mountains. Yes, it was warmer 2,000 years ago, too. But probably someone forgot to announce to the people back then that they were living on the brink of a catastrophe or something.<p>Before anybody asks: Yes, lets clean the oceans. Lets plant trees. Lets adapt to the climate change. Lets invest in robust energy sources which are not dependent on wind or sun for which we have to cut down forests and destroy seas. But don't be that arrogant to think that using a master plan we can control a complex, non-deterministic, loopback-based system on the edge of chaos.<p>This never happened. And this never will. And those systems are always "irreversible" because that's the nature of it.
It was refreshing to see Greta delete her "were all doomed in five years tweet from 2018" last week. They also took down the signs in Glacier Park that predicted the glaciers would be gone by now near where I live.