I think you misunderstand what a whole life CO2 assessment is. It factors in the carbon per longetivity. Often you will also be assessing other factors like cost per co2 too.
Rail is a predominantly upfront CO2 cost in infrastructrue for much lower operational CO2 costs and as such these questions are quite important if your job is decarbonisation of Rail.
We need decarbonisation across all sectors so minimising lifetime CO2 of infrastructure - even public transport infrastructure is absolutely a priority.
Discourage people using the train during a climate crisis.
I do think HS2 will just end up being finished. No other way.
Largely limited by government desicion if I remember. Hoping the new government make it substantially easier with the flick of a pen...
The answer to your questions are: yes it's a different baseline to the one chosen by the Paris agreement, different baselines are chosen for relevant to different elements of the issue. Likely the baseline chosen in your link is down to what reliable data they have and so they choose a baseline from a region of data they have rather than going to other sources. This website provides the latest years official record in Paris Terms I would expect the next one (2024) to be much closer to 1.5°C. On (2) I agree that current measurements suggest an instantaneous/yearly temperature around 1.5°C against the relevant baseline. On (3) you are right that the trend is unlikely to change because it comes from radiative forcing (emissions) that have already occurred so even with sudden zero human emissions we would see an increase or best case a leveling (before maybe long term it can decline as CO2 is naturally removed from the atmosphere or faster if humans find a way of doing so at scale). A trend however is already an average of several time points and you can see in the link you said that year on year variation on that number can be as high as say ~0.3°C. This comes about from non-GHG forcing elements of the system (such as El Niño) that add natural variation. So already you could see 2019-> dropped by 0.2°C even though the trend is up. So you could expect us to potentially drop back down to say 1.2°C for a few years before it goes up again. The link above suggests the best data we have we would likely breach 1.5°C by 2031 so not long at all.
This sounds like a pedantic point but it's actually quite important for the climate and the confusion stems back to how the problem and climate science was chosen to be communicated. Temperature was chosen in part because it's a proxy variable of other parts of the system that are what control the system impacts and it was felt that Temperature would be "naturally understandable" by the general population (and politicians...). This had a bit of a backfire because 1.5°C is not a lot of different when considered in say a room and it highlights why this variable is different and why it matters that it's decadal average rather than a yearly. So if temperature is only a proxy then what are the variables that control the outputs? One key one is the total heat energy stored in different earth systems and there the size of the storage medium matters (so the reason 1.5°C on the world is a lot but on a room isn't is because the sheer volume of the earth you have to have a huge amount more energy). The other place where Surface Temperature adds confusion and complexity is because of the oceans: the oceans have been absorbing some of the heat and that hasn't always been visible to us (as we don't live in the ocean) so if we stopped emitting today the ocean may then deposit some of that heat energy back into the atmosphere so it's a complex interaction. What we really need to know is what the additional level of radiative forcing and how much additional heat energy swimming about in Earth's systems - that is what will control the experience we have of the climate. Greenhouse gases act to stop Earth cooling back down by radiating out to space which is why the effect is cumulative so the difference between a sustained year on year 1.5°C and something that averages less but has a few years of 1.5°C is quite high because they will be different amounts of total energy in the system as a result.
So, the short answer is that the Paris agreement targets are set on the basis on what a decadal rise of 1.5°C by 2100 (i.e the average 2090-2100) means in terms of the excess heat energy and radiative forcing in the system. The limit itself is somewhat arbitrary driven in part by the fact we were at ~1°C when it was agreed and 2°C seemed like a reasonable estimate of something we might be able to limit it to. The origin of 1.5°C rather than 2°C is actually quite interesting and highlights a lot about how climate change policy has been decided but this post is long enough.
This is a good point. The sheet apocalyptic magnitude of the problem means that every tiny amount of change matters. Billions will die. There probably isn’t a way to prevent that completely anymore. But if we can tick things down by a fraction and save a few hundred thousand people, preserve a species of food crops that would have gone extinct, IDK what the exact outcomes are but the point is tiny changes will have a massive impact and they’re important even if the situation is dire.
Agreed, I think this is the right way of thinking about it and the risk of having communicated it to the world as a binary target of 1.5C/2C we risk people completely switching off if/when we finally confirm we've breached it when the reality is it should embolden us further not demoralise us. This is my number one concern at the moment. I would also add that what we doing is "pushing" a system away from it's natural equilibrium and if we push hard enough we might find that we find changes in the system itself which are very hard or impossible to undo. So it's more than just more increase more damages it's also about risks of fundamentally and permanently changing the system.
As an analogy think of the ball in the well of this local minima and we push it back and forth. If we hit it hard enough rather than come back it goes and finds another minima which is just a whole different system than we are used to. These are sometimes called tipping points and the frustrating thing about the complexity of the systems is we don't and can't know for sure where those points are (although we do know they increase heavily as you move above 1.5C upwards). They by definition are hard to model because models are built up from prior experience (data) and these are in part unprecedented changes in the atmospheric records.
I haven't mentioned "negative emissions" technologies but it is worth saying in principle you could have a situation where we are able to do significant negative emissions and that might mean we could end up with 1.5C in 2100 whilst having a period of time above it but negative emissions technologies could be a whole other rant. Worth noting though that lots of the pathways that show we could just about keep to 1.5C do rely on negative emissions to different degrees (though also the pathways are limited in how much they think we might be able to push our economic systems).
I see this misconception a lot and it's really unfortunate. We aren't at what climate scientists call 1.5°C. Being at 1.5°C in the means the average anonomly being over 1.5 for a period of decades. It isn't just a case of scientists being cautious it a completely different impact in the climate. It implies different amounts of impacts and different levels of heat energy in the whole system.
Yes we have hit 1.5°C over the last 12months partly down to el nino which is expected to subside shortly. Though there is some discussion about whether this year was an expected randomly anonomly or whether it suggests some feedback loop that's been underestimated but we can't know until enough time has passed (maybe a year).
All that just means both that the impacts we are already saying are less worse than you'd expect at long term 1.5°C and therefore we should be extremely worried but also that we have factored that in in our estimates of what outcomes are possible (though the 1.5°C window is increasingly narrow because as you say we still have our foot on the gas). So there is still time to make an impact and every fraction of a degree and kg of CO2 matters.
I'm not really sure that's true. Labour has also downgraded its climate ambitions and ruled lots of necessary change out in favour of promising technosolutions. That means when change is needed the expectations have not been managed and we risk a megabacklash. The victory is dramatic and large but mainly due to FPTP. The victory is very shallow beneath the surface with lots of marginal seats and in lots of them Tory+Reform share is bigger than the labour share.
We can absolutely enjoy this moment but the big fight for climate I think has only just begun in the UK.
Just to be clear I wasn't being feacious genuinely curious as to the specifics as I'm not as familiar with haulage.
I suspect there is an argument that we've made cargo transport too cheap and its skewed the economics of local vs outsourced production.
My preference would be pantograph systems on the motorways and main routes which we could roll out quite quickly and remove the majority of emissions coupled with a systemic look at our material needs and production capacities locally with a view to lowering volumes
The Silvertown tunnel (and lower thames crossing) in London would be a good example where we are rebuilding our infrastructure along the lines of sustained and increased haulage along certain routes at great public expense so I guess this could be considered an indirect subsidy.
What subsidies do they get?
The idea is GDP is a measure of activity. So using per GDP allows you to see the efficiency which you are producing "value". That's not a terrible idea in general but it accepts a very narrow definition of value.
GDP is a really flawed measure of how well a society is performing. I wonder what it would look like if we used Gross National Happiness or Total Quality Life Years. Could also think about ecosystem health or biodiversity as a valuable output of a country but that's highly linked to CO2 emissions so wouldnt be meaningful.
Also worth saying whilst per capita is absolutely important as a measure for us to understand the performance of human economic systems the earth systems only respond to gross total emissions.
I won't rehash the arguments around "AI" that others are best placed to make.
My main issue is AI as a term is basically a marketing one to convince people that these tools do something they don't and its causing real harm. Its redirecting resources and attention onto a very narrow subset of tools replacing other less intensive tools. There are significant impacts to these tools (during an existential crisis around our use and consumption of energy). There are some really good targeted uses of machine learning techniques but they are being drowned out by a hype train that is determined to make the general public think that we have or are near Data from Star Trek.
Addtionally, as others have said the current state of "AI" has a very anti FOSS ethos. With big firms using and misusing their monopolies to steal, borrow and coopt data that isn't theirs to build something that contains that's data but is their copyright. Some of this data is intensely personal and sensitive and the original intent behind the sharing is not for training a model which may in certain circumstances spit out that data verbatim.
Lastly, since you use the term Luddite. Its worth actually engaging with what that movement was about. Whilst its pitched now as generic anti-technology backlash in fact it was a movement of people who saw what the priorities and choices in the new technology meant for them: the people that didn't own the technology and would get worse living and work conditions as a result. As it turned out they were almost exactly correct in thier predictions. They are indeed worth thinking about as allegory for the moment we find ourselves in. How do ordinary people want this technology to change our lives? Who do we want to control it? Given its implications for our climate needs can we afford to use it now, if so for what purposes?
Personally, I can't wait for the hype train to pop (or maybe depart?) so we can get back to rational discussions about the best uses of machine learning (and computing in general) for the betterment of all rather than the enrichment of a few.
Triple the cost and start building mixed use developments on them.