Humans have caused 1.5 °C of long-term global warming according to new estimates

The last IPCC report estimates that to limit warming to 2C, humans can only emit at most 1150 GtCO2 (at 67% likelihood) [1].

There are 8.2 billion humans, so about 140tCO2/person left on average. If we assume that we get to net zero by 2050, that means the average person can emit about 5.4tCO2/person/year from today to 2050 (hitting 0tCO2/person/year in 2050). This is what emissions look like currently [2]

    Top 5 countries > 10m population
    Saudi Arabia  22.1t 
    United Arab Emirates 21.6t  
    Australia            14.5t 
    United States  14.3t
    Canada          14.0t
    Some others
    China           8.4t
    Europe 6.7t
    World average 4.7t
    Lower-middle-income countries of 1.6t
    Low-income countries 0.3t

Guess what's going to happen and who is going to suffer, despite not doing anything.

[1] Page 82 https://www.ipcc.ch/report/ar6/syr/downloads/report/IPCC_AR6...

[2] https://ourworldindata.org/co2-emissions-metrics

> that means the average person can emit about 5.4tCO2/person/year from here on out. This is what emissions look like currently

Using a world average target number and then presenting a list that leads with world outliers is misleading. This is the kind of statistical sleight of hand that climate skeptics seize upon to dismiss arguments.

The world average is currently under the target number:

> World average 4.7t

I think you meant to imply that the CO2 emissions of poor countries were going to catch up to other countries, but I don’t think it’s that simple. The global rollout of solar power, battery storage, and cheap EVs is exceeding expectations, for example.

I don’t want to downplay the severity of the situation, but I don’t think this type of fatalistic doomerism is helping. In my experience with people from different walks of life, it’s this type of doomerism that turns them off of the topic entirely.

I believe the causation runs the other way. The IPCC was founded in 1988, when CO2 emissions were 22 gigatons per year. Nearly four decades later it's 40 gt/y, and continuing to rise.

Doomerism is the reaction to our utter failure to even pretend to try. It did not cause that failure. Nor are people looking at the data and going, "yeah, I ought to do something, but people on Hacker News were gloomy so I'm going to buy a bigger SUV instead." EVs and solar and suchlike are much, much, much too little and much, much, much too late.

Doomerism doesn't help, except in the extremely limited sense of helping someone express their frustration. But it also isn't hurting because we'd be doing exactly the same nothing if they were cheerful.

The comically named Inflation Reduction Act included a tremendous amount of money for scaling up clean tech manufacturing in the US, and it’s been getting deployed quickly. The DOE Loan Programs Office got something like $400B in loan authority. Overall, the IRA was probably the largest single bit of climate action the US govt has ever taken. Unfortunately, people mostly hear about that work when it becomes part of political football (Solyndra and Tesla both got money from the DOE LPO to help them scale up, and the political fallout from Solyndra was the first time most people had heard of it). But it’s happening.

> included a tremendous amount of money for scaling up clean tech manufacturing

It included a moderate amount of money as stimulus to commercial companies which manufacture clean(? clean-er?) tech.

The Biden administration has also "balanced" this by allowing for massive amounts of further drilling for fossil fuels.

And even without the "balancing" - this is not remotely like an actual plan to convert the US to near-zero-emission energy production, in the immediate future, which is what's actually necessary.

$400B is moderate? Have there been other bills that have come anywhere close?

Did I say moderate? I should have said small. Remember this is $400B over a 10-year period, i.e. $40B per year. The US federal budget is $6.1T per year, so not even 1% of the annual budget.

It is also small in terms of the extent of expenditure needed for such a conversion of the US energy production system. A cost estimate from 2019 suggested somewhere between $4.5T - $5.7T over the whole period:

* https://www.instituteforenergyresearch.org/renewable/cost-of...

* https://www.greentechmedia.com/articles/read/renewable-us-gr...

so $400B - even if we could assume that all goes directly to achieving the goal, which it does not - is under 10%: