Thread by @safiume

If we went hit net-zero or carbon neutral today, how much carbon do we need to remove to maximize diversity and climate restoration by 2100? See thread for more info on #beyondneutral #climateaction #climatejustice @ExtinctionR

Fossil fuel emissions since 1750, have spread between the air, oceans, and land. By the latest count per the globalcarbonproject.org, the distribution looks like the linked chart. Multiply by 3.664 to convert the amounts to gigatonnes carbon dioxide. (1.7 Tt CO₂ & 2.4 Tt CO₂)

How big is this amount? The brown+red bars equals about 656 Gt Carbon by weight which is about 2M Empire State buildings. This amount is roughly equal to all green and blue bars and should be removed to restore the planet. bluebulbprojects.com/measureofthing…

If we kept the landsink as productive as it is today or made it more productive, how much do we need to address? The red bar equates to fossil fuel emissions, and is distributed to the blue bars: oceans and atmosphere. That amount is roughly 1.5 M Empire state buildings.

These numbers get larger if we don't stop using fossil fuels. We need to quickly cut back on fossil fuels as we ramp up in renewables and switch over. This is doable, most of the technology already exists. And we need to go as fast as possible by also doing CarbonDioxideRemoval

What happens if we don't do it? If we don't switch before melting the East Antarctic ice sheet, we'll have to suffer the consequences of even more accelerated warming-induced catastrophe: droughts, starvation, etc. as all other tipping elements would have already been tipped.

Current science predicts it's not possible to return after tipping past the last tipping point. doi.org/10.1073/pnas.1…, phys.org/news/2019-11-c… #ClimateCrisis

We have to reach neutral no later than 2030, ideally sooner to maximize the biodiversity we still have. As we come out of Corona lockdowns we need to sharply cut fossil fuel use and increase in renewables deployments and efficiency products.

Before reaching neutral we need to expand R& especially D in DirectAirCapture (#DAC) and Carbon Dioxide Removal (#CDR). At neutral we need to be ready to deploy large scale CDR projects. Think lots of Stripe Carbon Negative purchases. & stuff like barrons.com/video/green-en…

Once safely away from setting off the tipping points and have reversed them, we might be able to back off a tiny bit. However, bit.ly/CDRMEx (uses SW model also used by IPCC) predicts to reach 0ºC of warming, all anthropogenic carbon must be removed.

Amazingly, we don't have full AMGCMs run with reaching neutral before 450 ppm, (activating more tipping elements) and seeking 0ºC of warming. We only have models that end with less than 1.5ºC of warming but warmer than the year 2000.

We should study reaching neutral asap and before hitting 450 ppm, and seek full restoration by 2100 on a full Atmosphere-Ocean General Circulation Model. bit.ly/cdrmexprj

If we reach neutral today we still have carbon in the atmosphere and oceans that we must remove in order to get to less than 1.5ºC. And we have even more emissions to remove if we want to seek #climatejustice #climateequity.

What is this amount for complete climate restoration by 2100? It's on the order of 1.7 to 2.4 trillion tones of CO2. It's the last option in the poll. Want to maximize biodiversity? It's the last option in the poll.

We have to not only reach carbon neutral but continue that work to reach neutral and exceed that amount and go negative to pull out vast amounts of carbon every year till 2100 to restore the climate to have the same level of heat that it did before 1900. #ClimateJustice

As a metaphor, we have to turn off the tap and keep baling emissions until the tub is empty. We've been filling the tub since 1750. It's at best just the red bar, at worst we need to bail the red and brown bars:

We as humans have to decide if it's worth it to give up our fossil fuel habits and use new technology or stop using fossil fuel-powered devices in order to have a better climate tomorrow, in 2040, 2050, 2060, 2070 and onward to 2100. Vote!

Actually, that poll not worded correctly! At, the worst case if we wait till 2030 to do any removal, or hit neutral, we'll have exceeded the carbon budget and would need to remove ≈3 trillion tonnes of CO₂. If we were to start seeking net-zero now, it's closer to about 2TtCO2.

(This is assuming we keep the land sink as productive as it is now.) The land sink is about 500Gt CO2 currently. I'm very interested in the principle, are people interested in making choices to maximize biodiversity? Are we willing to make our livelihoods more STEM-based?