Ian Campbell
iancampbell.bsky.social
Ian Campbell
@iancampbell.bsky.social
Doctor, statistician, policy scientist, passionate about science-based decision making.
Carbon footprint & carbon budget calculators: http://carbonindependent.org
The maths of limiting global warming:
For 1.5°C, the UK’s fair share of the global carbon budget runs out in 2027
- needing Net Zero 2030, and closure of most airports within a few months
- 1.6°C needs Net Zero 2035, and closure of most airports within 1 year.
(www.carbonindependent.org/177.html)...
October 3, 2025 at 7:08 AM
But the @rozsavage.bsky.social version of the #CANBill abandoned 1.5°C and abandoned equality for developing nations.

That will mean 1.8°C and 100 million more climate deaths if repeated globally - see www.carbonindependent.org/174.html

TBH that’s not standing firm - that’s wimping out.
September 26, 2025 at 8:55 AM
Systemic appeasement in relation to the CCC / UK Government / NZ 2050 nonsense is not restricted to the research and academic mitigation community.

It's also very common within the climate campaigning community.

The table summarises some 2023 assessments - see www.carbonindependent.org/154.html.
September 5, 2025 at 8:35 AM
If every country did the same, global warming would be c.2.0°C, according to the IPCC’s calculated carbon budgets - 100 million extra climate deaths and enormous biodiversity loss.
So the 2nd CAN Bill doesn’t properly address the climate emergency
Details & refs: www.carbonindependent.org/174.html
August 27, 2025 at 7:49 AM
It's worth looking at what climate scientists are actually saying, e.g. @kevinclimate.bsky.social‬ e.g. at www.youtube.com/watch?v=barR...
This talk says the UK’s NDCs and the UK's Net Zero 2050 emission reduction pathway would take 3x the UK’s fair share of the global carbon budget for 1.5°C.
August 27, 2025 at 7:49 AM
Sadly, it isn’t true that the CANBill is a robust, science-led, plan that properly addresses the climate emergency.

The 1st CAN Bill was radically changed, and the 2nd CAN Bill merely endorses the UK Government’s NDCs (its voluntary emission reduction targets).
August 27, 2025 at 7:49 AM
The IPCC AR6 report says this would give global warming of c1.8°C (see image).
The extra 400 Gt CO2 (900 Gt compared to 500Gt for 1.5°C) would lead to 100 million extra climate deaths (at 1 death per 4000 tonnes CO2 - see www.carbonindependent.org/144.html).
Hence my concern re Zero Hour's messaging
August 21, 2025 at 8:06 AM
The UK’s NDCs & its Net Zero 2050 Strategy would lead to c. 8 billion tonnes (Gt) CO2 emissions since Jan 2020, see Zero Hour’s Ambition Gap report (image) or www.carbonindependent.org/174.html
Scaled from the UK’s 68 million to the global 8.0 billion population, this would be a bit over 900 Gt CO2
August 21, 2025 at 8:06 AM
But how many of the 1200 scientists who supported the 1st #CANBill now support the 2nd #CANBill, which has abandoned 1.5°C and merely endorses Net Zero 2050?
Do @thierryaaron.bsky.social or @tristramwyatt.bsky.social?
100 million extra climate deaths isn't trivial.
www.carbonindependent.org/174.html
August 20, 2025 at 7:11 AM
I’ve still had no reply to my question about the 2nd #CANBill far exceeding the UK's fair 1.5°C carbon budget, leading to warming of 1.8°
Can @sioldridge.bsky.social@sarahew.bsky.social‬ or @atoxley.bsky.social‬ answer this please?
This is the 6th time I've asked
www.carbonindependent.org/174.html
August 8, 2025 at 7:31 AM
Thank you.
This is how my questions were ‘answered’ before - they weren’t.
And those questions related to the 1st CAN Bill.
That wasn’t good enough, and your reply yesterday wasn’t good enough.
Please answer my question about the 2nd CAN Bill.
Millions are dying - we should all be working together.
July 31, 2025 at 7:16 AM
My calculations are the #CAN Bill would lead to UK emissions of 7.9 Gt CO2 - twice the UK's fair share for 1.5°C
Scaled up to the global population, this would lead to global warming of 1.8°C
See www.carbonindependent.org/174.html
Does Zero Hour get the same figures?
This is the 3rd time I've asked
July 29, 2025 at 7:05 AM
My calculations are that the #CAN Bill would lead to UK emissions of 7.9 Gt CO2 - twice the UK's fair share for 1.5°C.
Scaled up to the global population, this would lead to global warming of 1.8°C.
See www.carbonindependent.org/174.html
Does Zero Hour get the same figures?
#BringScienceToActivism
July 25, 2025 at 7:11 AM
It’s a great pity the briefing doesn't reflect the gravity of the climate situation.
It adds to the misconception that the UK Gov’s Net Zero 2050 timescale is adequate - but the UK’s fair share of the global carbon budget for 1.5°C runs out in 2 years - www.carbonindependent.org/files/SGR_RS...
...
July 6, 2025 at 6:51 AM
Why is Living Streets calling for a pavement parking ban when it's already illegal?
What abysmal incompetence.
Vulnerable people need the existing ban enforced, and they need Living Streets to stop spreading misinformation.
July 4, 2025 at 5:56 PM
What emission reduction pathway would the CAN Bill lead to, please?
It seems to be minor reductions for 2 years, then reduction to zero by 2030. Is this correct? It seems ludicrous.
This is the 4th time I’ve asked - nobody in Zero Hour seems to know.
My critique: www.carbonindependent.org/174.html
July 1, 2025 at 7:18 PM
The article would be much improved by including the vital information that the UK’s Net Zero 2050 timescale falls far short of the UK’s Paris Agreement commitments on 1.5°C.

The UK’s fair share of the global carbon budget for 1.5°C runs out in 2 years - see www.carbonindependent.org/files/SGR_RS...
June 27, 2025 at 5:19 PM
Actually, the science is that the UK needs Net Zero 2030 (linear decline) to stay within its fair share of the global carbon budget for 1.5deg (50% confidence) - see www.carbonindependent.org/177.html.
May 13, 2025 at 5:31 AM
Our international commitments to 1.5°C mean that most airports should be closed within months - but there is mass denial about this.
carbonindependent.org/177.html

#FridaysForfuture
May 9, 2025 at 7:01 AM
But what's needed from ‪@clientearth.bsky.social‬ is to tell the truth about the climate emergency, not endorse the Govt’s inadequate NZ 2050 timescale.
The UK’s fair #carbonbudget for 1.5°C is almost gone
Net Zero 2030 is needed - if the UK cares about its promises.
carbonindependent.org/177.html
March 30, 2025 at 5:28 PM
The UK's fair carbon budget for a 50% chance of 1.5°C runs out in 2027
(www.carbonindependent.org/177.html - an update of
@responsiblesci.bsky.social blog: www.sgr.org.uk/resources/uk...).
But many campaigners are understating the urgency of action and advocating inadequate policies.
It's a tragedy
March 28, 2025 at 5:48 PM
What emission reduction pathway does #ZeroHour have for the #CANBill please?
Is it like this chart with CO2 emissions falling 25% per year to zero by 2030?
See www.carbonindependent.org/174.html
If so, why not say so?
What's wrong with transparency and discussion?
We need to be working together.
February 15, 2025 at 12:30 PM
The UK's fair carbon budget for 1.5°C runs out this year (www.carbonindependent.org/177.html).
So the discussion should really be around the date by when most UK airport should close - March 2025?
February 10, 2025 at 6:43 PM
Isn't the strongest argument against airport expansion the rapidly dwindling UK carbon budget?
The UK's fair carbon budget for 1.5°C runs out this year (www.carbonindependent.org/177.html).
So the discussion should really be around the date by when most UK airport should close - March 2025?
February 4, 2025 at 12:53 PM
Can I ask you, please, what pathway of emission reduction does Zero Hour have in mind?
Is it like this chart, with CO2 emissions reduced by 25% per year to zero by around 2030?
See www.carbonindependent.org/174.html
February 1, 2025 at 9:26 AM