> That is hardly an uninhabitable world. It might be a very different world, with all sorts of new issues to deal with. But not uninhabitable.
Statements like this can be problematic because while the world in general may still be inhabitable, there could be particular regions that are not, or the damage cause by climate change can be too much for the people living there to deal with.
For example: right now Karachi, Pakistan, population 15M, seems to be basically totally underwater:
Some regions may not have the fiscal/political capital to deal with the changes wrought by climate change, and it is often the regions that did the least cause climate change that suffer the most. Most of the historical emissions that got us here were produced by the industrialized West (especially US), but they'll probably be bit the least-hard.
Last time I checked HN prided itself on being engineer and science based. The OP claimed things that are simply not true. I corrected him based on the UNs own findings that “99% of scientists” support or something similar. What I said is not problematic, but a fairly scientific and authority based view.
Just because certain political factions make climate change into a hysterical issue, doesn’t mean that this is actually scientifically accurate.
It would be helpful if we spoke about highly uncertain estimates like these differently, as the 2 degree rise is a middle-of-the-road "best guess" scenario in a complex system.
Their "best guess" isn't very good. What's your best guess for the number of COVID cases in your area in 2 months?
Things could be significantly worse than IPCC's estimate, or not that bad. We really don't know. From that uncertainty we should begin to think about things we can do to limit risk.
When there's relatively unbounded downside, you buy insurance (of various forms, financial, operational and other).
* The models are continuously updated. Recent measurements of land surface temperatures and polar ice sheets have been tracking worst case scenarios, not the previous expected mean (see e.g. Arctic ice sheet melt-off in 2020).
* There are considerable confidence intervals around predicted temperature increases and related forecasts, e.g. GDP growth.
* There are considerable nonlinear dynamics such as thawing permafrost or sea-floor deposits of methane, or death of carbon sinks such as forests. This means that the outcomes of the models can diverge wildly from the mean expected outcome.
* I believe IPCC models do not take into account the political upshot of massive loss of farmland and habitable land in the tropics (i.e., refugees and wars).
You mean that IPCC predictions based on climate models have been replaced by different predictions based on newer models as more data became available over time?
Unfortunately (for us) it does look like newer predictions predict worse outcomes with higher confidence [1].
PS: yes scientific consensus changes over time as a function of available measurement data and understanding. That's not a sign of failure but of improved scientific insight.
So you're saying some places are uninhabitable is the same as the planet being uninhabitable? Tell that to the Sahara.
Seriously, it's going to suck and cause many, many issues. But the planet won't be completely uninhabitable for many centuries, if it ever even happens, through man made climate change.
Do you remember the Syrian refugee crisis and how it destabilized pretty much all of Europe and how we're still dealing (or failing to deal) with the political consequences of these upheavals?
How do 1.5 billion migrations by 2050 sound to you? Yeah. Many many issues.
And I'm not even going into the discussion that the whole planet will be toast once we reach +5 degrees celsius, which looks more and more not only like a extreme outlier but a real possibility instead.
> The IPCC predict 2 degree rise by 2050, and a 6% reduction in gbp growth, not gbp.
IPCC models don't take into account the feedback loops.
Also , things are moving faters alredy that they have been anticipating, so expect these predictions to be completely obsolte in few years.
The IPCC's 2 degree rise is rather optimistic and -- as others have pointed out -- doesn't take into account feedback loops and tipping points, mostly because the models are not sophisticated enough.
Add that to the massive ecosystem disruptions that are already taking place, add the political unrest that will follow from the tsunami of migrants that are trying to just survive and you have the perfect ingredients for an pretty much uninhabitable planet.
Maybe not in the next 25 years. The next 25 years we will just have massive unrest, political upheaval, wars, ecosystem collapse and genocides.
I'm not so optimistic about the 25 years after that, though.
Statements like this can be problematic because while the world in general may still be inhabitable, there could be particular regions that are not, or the damage cause by climate change can be too much for the people living there to deal with.
For example: right now Karachi, Pakistan, population 15M, seems to be basically totally underwater:
* https://www.theguardian.com/world/2020/aug/26/pakistan-flood...
* https://www.dw.com/en/flooding-causes-havoc-in-karachi/a-547...
Tuvalu and the Marshal Islands are predicted to basically disappear:
* https://www.theguardian.com/global-development/2019/may/16/o...
* https://en.wikipedia.org/wiki/Effects_of_climate_change_on_i...
Some regions may not have the fiscal/political capital to deal with the changes wrought by climate change, and it is often the regions that did the least cause climate change that suffer the most. Most of the historical emissions that got us here were produced by the industrialized West (especially US), but they'll probably be bit the least-hard.