We're definitely going to go beyond 2ºC in the coming decades.
Even if a miracle happened and we stopped all human emissions today, current GHGs in the atmosphere will keep trapping more heat for some decades. This is known as climate inertia or climate lag.
Another aspect I don't see frequently mentioned are feedbacks. Again, even if we stopped all emissions today, self sustaining climatic systems will keep adding more heat to the atmosphere (methane, etc) or the sea (Arctic ice melting).
We're currently at aprox 36 billion tonnes of carbon emissions per year [1] only counting fuel burning. It would be a miracle if we could even reach 50% of that in our lifetime, which was aprox the emissions from the 70s.
And a quick reminder that the IPCC reports/estimates excluded arctic methane emissions...which we a) now know are definitely happening and b) are just catastrophic positive feedback loops.
Can you link to some sources on point B? From what I've read you'll find broad scientific consensus on your point A but your point B is not even close to widely accepted among climate scientists.
That said I've learned the science can change rapidly, so I'm all ears if the position of the majority of climate scientists has shifted.
It looks bleak. There are fewer and fewer options remaining. Carbon sequestration at the source of emissions could reduce some CO2 from big fossil fuel power stations, but won't fix vehicles. We need a miracle technology that can actually extract CO2 from the air. Planting 1 trillion trees might help, but we won't do it.
Usable fusion doesn't exist today and the problem is immediate, it is that simple. We are at the point of solving it with what we have, not helplessly waiting for a deus ex machina.
Everyone (especially the environmental activists) need to come to the realization that we've long passed the point where we have the luxury of being picky over what we replace our fossil fuel (carbon emitting) energy sources with.
While everyone has been arguing about hydroelectric versus nuclear fission versus truly renewable sources versus "just wait for fusion", the energy consumption of humanity has been exponentially growing and satisfying that desire primarily with carbon emitting sources of power.
All options need to be on the table. Mandate solar panels on roofs, mandate battery storage in homes, build utility scale PV and solar thermal plants where it makes sense, build wind farms where it makes sense, get over our fear of fission and build many small, yet passively safe nuclear fission plants and the necessary fuel recycling facilities to reduce the need for spent fuel storage.
Tell anyone who thinks that renewable power sources look ugly to shove it.
Rather than focusing our collective energies on developing more energy generation tech, pivot to figuring out how to sink carbon we've already emitted and use existing generation solutions until the problem is controlled. Then start looking at the future again and offline whatever is obsoleted.
Fusion research hasn’t ever been funded well enough to hit the various timelines. If people fund it, or if computing power gets cheap enough to solve the remaining research problems in-silico rather than with a demo reactor, we could plausibly get it in 5-10 years.
But I agree with @gnfargbl, we should use the naturally occurring one that we orbit.
The issue is a lack of designs with promising commercial application. The world has dumped plenty of money into fusion design research since the 50s but only very recently created a design that could actually generate more power than it consumes containing the plasma field.
The current most effective designs output 1.25w for every watt of input. And only at a very small scale. It's great that we can finally produce net energy from fusion. But let's not get ahead ourselves here. The issue is not funding, it's lack of brain power. Fusion is an insanely difficult nut to crack and trillions of dollars won't do crack it alone.
I had similar discussions ten years ago with a Cambridge PhD in this field, who was of the opinion that the money spent on Iraq War would have been more than enough to resolve all known fusion reactor related questions (he explicitly did not say the result would be a working reactor).
ITER is set to come online in the next couple of years with a price tag of around $50,000,000,000 !!!! And it will spend 20 or so years testing various fuels.
China is building their own tokamak reactor to compete with ITER. I can't find cost figures, but presumably costs are roughly the same, considering the same size and is intended to "compliment" ITER.
These are still merely "test" reactors. They are experiments that may provide some enough data in 10-20 years such that another, even larger and more expensive test reactor may be constructed. Assuming ITER runs until 2045 and a replacement is started on in 2040. With 10 years of construction time, and 20 more years of testing, that means the next generation is set to complete testing in 2070. And hopefully the results of that generation will give us an idea of how to build a commercially viable fusion reactor.
All the funding in the world isn't going to change the fact that testing is a long-drawn out process, and that it must be performed in a somewhat linear fashion. The results of the previous experiments inform the next generation. And we are still a few generations away from commercial viability.
I do want to point out that I'm a strong advocate for fusion research. I just don't see it as a viable solution to global warming, regardless of how much we fund it, because we don't even know what a commercially viable reactor even looks like yet, much less be able to scale the technology out to the point that it will put a dent in CO2 emissions.
$50bn looks (eyeballing it) like less than the area under the graph labelled “moderate”.
You and I both agree fusion isn’t likely to be the solution to global warming, but I do think it could be if people wanted it to be. (I also think nobody with the money to spend really cares that much about fusion, and that PV is so absurdly cheap this is unlikely to change).
There's been a lot of interesting progress recently using high-temperature superconductors that weren't available when ITER was being designed. This should make fusion a lot more attainable and practically useful.
That said, I don't think we should count on fusion to get us out of this when renewables are a good-enough solution that's available now and they're cheap. (If storage is an issue, perhaps that means we should be investing in long-distance transmission lines so we can, for instance, power North America at night using solar panels in the Sahara.)
At this time, albedo modification is not politically correct, because it would still work whether human action is the main driver of global warming or not.
There is also the negative feedback of plants growing faster due to increased available CO2 for them to use.
It would be interesting to see the list of all feedbacks and estimated significance.
There's also the wildcard of algae evolution. Since there are quadrillions of them, evolution happens very quickly so changes in ocean acidification and temperature could substantially change how efficiently they work. They could get better or worse.
Do you have and references on your last point about algae? I have this (totally unsubstantiated) idea that plundering the oceans of fish along with rising temperatures will result in the oceans sequestering incredible amounts of CO2 via algae blooms. Never found much to read on the topic though - in what ways could this be negative feedback loop?
yeah, the n-th order effects like the siberian ice melting away into methane emissions equivalent to 100 years of 2020 CO2 output will just completely obliterate any efforts at mitigating new emissions.
That article doesn't say anything about how much methane is being released. The fact that it's happening isn't being disputed. The prediction that it will be catastrophic is.
Oh, it will absolutely be catastrophic if the Siberian tundra thaws. Have you seen the estimates for how much carbon is locked in the permafrost? It's more carbon than is in the atmosphere today. [1]
Did you mean to write "if it keeps speeding up"? Because it is most definitely happening, it is speeding up [1], and it doesn't look likely to slow down.
The fact that it's happening isn't being disputed. The prediction that it will be catastrophic is.
The NASA article you linked is reputable, but pay attention to what it actually says - it makes no predictions of impact severity.
What the article DOES say: methane is responsible for 1/4 of all global warming, it's increased 9% in the last decade, and 250% in the last 17 decades (avg 15%/year).
Even if a miracle happened and we stopped all human emissions today, current GHGs in the atmosphere will keep trapping more heat for some decades. This is known as climate inertia or climate lag.
Another aspect I don't see frequently mentioned are feedbacks. Again, even if we stopped all emissions today, self sustaining climatic systems will keep adding more heat to the atmosphere (methane, etc) or the sea (Arctic ice melting).
We're currently at aprox 36 billion tonnes of carbon emissions per year [1] only counting fuel burning. It would be a miracle if we could even reach 50% of that in our lifetime, which was aprox the emissions from the 70s.
[1] https://ourworldindata.org/co2-emissions