[konspence]

There's nothing to "keep" under 1.5C, we are pretty much already there when error bars are considered. 2C is going to be breached regardless because even if we went carbon neutral today we have decades of locked in warming.

Why the scientists are not communicating this information which has been in pop-science (as early as An Inconvenient Truth (2006), which documents the lag between CO2 rise and temp rise) is beyond me.

I still advocate for mitigation/reduction efforts because future generations exist and they deserve the best climate we can pass on, but let's not pretend like we are on track to preserve any level of normal. 1.5C is more than a moonshot - it is behind us.

[johnchristopher]

> Why the scientists are not communicating this information which has been in pop-science (as early as An Inconvenient Truth (2006), which documents the lag between CO2 rise and temp rise) is beyond me.

I might be biased but popular newspaper in my country have interviews in which scientists do talk about that.

[konspence]

Please share.

[ttiurani]

Don't quite know what you mean by "locked in warming" (nor didn't have time to look at this report yet), but the previous scenarios have massive scale future magic carbon takeback tech baked in. I assume if there was something like that ongoing on a global scale and almost no new emissions, 1.5 degrees might be theoretically possible?

[konspence]

Thanks, good call out. This was largely based on some charts from An Inconvenient Truth which showed temp as a latent responding variable to CO2 PPM.

Obviously a lot of research has happened since then, so I looked it up, and the lag period between CO2 and temperature rise is much shorter than I expected. It seems it is just a decade - so if we went to carbon negative today, we could see results in under 10 years [1] [2].

Kind of unclear if the baseline carbon we could achieve will result in YoY decrease in temperature, given the feedback loops and it already raising temperatures every year.

If the research you mentioned is predicated on massive carbon takeback then I am highly suspicious. The public sector doesn't have the will, and the private sector doesn't have the incentive.

[1]: https://iopscience.iop.org/article/10.1088/1748-9326/10/3/03...

[2]: https://climate.nasa.gov/faq/16/is-it-too-late-to-prevent-cl...

[miltondts]

Here's a report on a study that shows we are already at > 2C: https://www.ecowatch.com/greenhouse-gases-paris-agreement-26...

[clydethefrog]

Because they are not popscientist, but a very professional body of scientists that will only go for the most conservative, solid information.

What also plays a role is that before the final report it has to be seen and corrected by governmental representatives.

[whimsicalism]

The exact way climate lag functions is still a very uncertain science. It is communicated, but it can't be communicated we because (unlike how Al Gore portrays it) the evidence around how long the lag is is still very uncertain.

I've done a lot of research into this because I am interested in climate lag.

[ForHackernews]

They are not communicating that because they don't want people to lose hope and give up, even when that's probably the rational response.

As you say, these changes are already "baked in" and the natural environment is only to get more hostile to humans from here on out.