Thread by @Jumpsteady

This thread gives you the best moments of a presentation held by climate scientist Professor Will Steffen, held in Australia in June 2018.

You should really watch this as he finds exceptionally clear words to describe the urgency of our situation. #ClimateCrisis

[THREAD 1/13]

Professor Will Steffen explains the concept of carbon budgets, its limitations and how much time we have left. He also talks about probabilities and why we can’t have a 75% chance anymore to hit the Paris 2°C. We have simply blown the available budget already.

[THREAD 2/13]

In this part of his presentation Professor Will Steffen points at the risks in food production that we are going to face at 2°C warming. #ClimateChange will act as a multiplier for other threats. "When people are starving, they either move or they fight. Or both."

[THREAD 3/13]

Will Steffen: "I ask people how much colder was the last ice age. The common answer I get is about 20°C. Well the difference between now and the depth of an ice age is 4°C. So talking about going up by 4°C, we're talking about an unrecognisable state of the earth."

THREAD [4/13]

In this part Professor Will Steffen is showing the climate of the Holocene and zooming in on the last 2000 years and the rates of change. "This is just far too fast for natural ecosystems to cope with."

[THREAD 5/13]

This is important.
Professor Will Steffen: "Unfortunately this is the way 99.9% of the time scientists present projections for the future. You got to do it another way… There aren’t many scientists who think we will actually meet the 1.5°C target."

[THREAD 6/13]

Professor Will Steffen explains that there will be no in between state. "In other words, if we miss the 2°C target we might not be able to get to 3°C because of tipping points in the system. If we blow that target there is no guarantee we are able to control it."

[THREAD 7/13]

Professor Will Steffen explains the concept of tipping points and focuses on the Amazon and permafrost. "There is a tipping point around 2°C where we will loose most of the Amazon rainforest. If we loose the permafrost there is no way are going to stop at 3°C."

[THREAD 8/13]

Professor Will Steffen explains about the tipping points of Greenland and Antarctica. He also introduces the concept of tipping cascades. "Tipping points are not going to act in isolation. Once we hit 2°C we hit a global tipping point that humanity cannot control."
[THREAD 9/13]

Tipping cascades are not part of the climate models yet. Professor Will Steffen about irreversibility: "Can we go back? No! You break the climate system, you own it." Business as usual could bring us to 7°C by 2300. Climate will not recover for thousands of years.

[THREAD 10/13]

Prof. Will Steffen explains reductions pathways. "Next realistic chance to peak global emissions is 2020. Then we can still hit the 2°C but we got to get out of carbon by 2040. But if we delay to 2025: Impossible! You’d have to totally decarbonise in one decade."

[THREAD 11/13]

Prof. Will Steffen explains what a 4°C world is like. "Changing rainfall patterns will make agricultural areas unproductive. A lot of scientists say about 1 billion may be able to live in a 4°C world. This is not going to be a gentle, planned population decline."

[THREAD 12/13]

Please feel free to pick out videos you like and retweet separately with a comment. This way we have a better chance of reaching out into other bubbles.

I can also recommend to watch the whole presentation. It takes about one hour:


[THREAD 13/13]

This is the graph shown in this video. We are only talking about projections until 2100 and we act like #ClimateChange will suddenly stop then. No. It is a politically set date. And of course #globalheating will continue after that. This graph shows 7°C until 2300. Uninhabitable.

This is the same graph shown in this video taken from Professor Steffens lecture on "Climate Science and Policy" available on edx free of charge. I can strongly recommend this: edx.org/course/climate…

BonusTweet [13+1/13]

If you feel helpless now, I understand that. I’ve been there too. But we need to get up and fight for our kids! #Actionhelps
@Psychologists4F

If you made it through all the 13 tweets and you still want to know more: 👏

More here:

BonusTweet [THREAD 13+2/13]

This might be interesting for you as well👇Exceptionally blunt.

A Panel discussion from 2018 with Nobel Price Laureate Steven Chu @energybroseph, Johan Rockström @jrockstrom, Lisen Schultz @resiliencer and Julian Dowdeswell.

This is the slide from this video and maybe the most important message of the whole thread. We might trigger a self-reinforcing heating like a domino effect which might not allow us to stop #GlobalHeating once we breach the first tipping point of the cascade. Expected around 2°C.