Robert McSweeney
@rtmcswee.carbonbrief.org
Senior Science Editor at Carbon Brief, with a fondness for baking and Arsenal FC. All opinions are my own, however dull they might be.
Here's our annual analysis of who is going to COP:
Top story: no US delegation for the first time in COP history
Also: ~56,000 people registered, so no big drop-off despite accommodation issues in Belém
(Caveat: these are provisional figures)
Also also: most "virtual" delegates ever
#COP30
Top story: no US delegation for the first time in COP history
Also: ~56,000 people registered, so no big drop-off despite accommodation issues in Belém
(Caveat: these are provisional figures)
Also also: most "virtual" delegates ever
#COP30
NEW – Analysis: Which countries have sent the most delegates to COP30? | @rtmcswee.carbonbrief.org Ho Woo Nam
Read here: buff.ly/I5pUBHu
Read here: buff.ly/I5pUBHu
November 11, 2025 at 2:16 PM
Here's our annual analysis of who is going to COP:
Top story: no US delegation for the first time in COP history
Also: ~56,000 people registered, so no big drop-off despite accommodation issues in Belém
(Caveat: these are provisional figures)
Also also: most "virtual" delegates ever
#COP30
Top story: no US delegation for the first time in COP history
Also: ~56,000 people registered, so no big drop-off despite accommodation issues in Belém
(Caveat: these are provisional figures)
Also also: most "virtual" delegates ever
#COP30
Reposted by Robert McSweeney
NEW – Ongoing failure to agree AR7 timeline is ‘unprecedented’ in IPCC history | @ayeshatandon.carbonbrief.org @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org
Read here: buff.ly/rSMdzNf
Read here: buff.ly/rSMdzNf
Ongoing failure to agree AR7 timeline is ‘unprecedented’ in IPCC history - Carbon Brief
Governments have, once again, failed to agree on a timeline for the Intergovernmental Panel on Climate Change (IPCC) seventh assessment cycle (AR7)
buff.ly
November 7, 2025 at 10:46 AM
NEW – Ongoing failure to agree AR7 timeline is ‘unprecedented’ in IPCC history | @ayeshatandon.carbonbrief.org @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org
Read here: buff.ly/rSMdzNf
Read here: buff.ly/rSMdzNf
Reposted by Robert McSweeney
NEW – Experts: The key ‘unknowns’ of overshooting the 1.5C global-warming limit | @ceciliakeating.carbonbrief.org and @rtmcswee.carbonbrief.org
Read here: buff.ly/yPWMH59
Read here: buff.ly/yPWMH59
Experts: The key ‘unknowns’ of overshooting the 1.5C global-warming limit - Carbon Brief
On the sidelines of a conference, Carbon Brief asked a range of experts what they consider to be the key “unknowns” around overshoot.
buff.ly
October 8, 2025 at 2:29 PM
NEW – Experts: The key ‘unknowns’ of overshooting the 1.5C global-warming limit | @ceciliakeating.carbonbrief.org and @rtmcswee.carbonbrief.org
Read here: buff.ly/yPWMH59
Read here: buff.ly/yPWMH59
Last week, @ceciliakeating.carbonbrief.org and I attended the first-ever conference on climate "overshoot" in Vienna.
Here's our summary of the wide-ranging discussions. (Bearing in mind we were two journalists covering 8 conference themes...!)
Here's our summary of the wide-ranging discussions. (Bearing in mind we were two journalists covering 8 conference themes...!)
NEW – Overshoot: Exploring the implications of meeting 1.5C climate goal ‘from above’ | @ceciliakeating.carbonbrief.org and @rtmcswee.carbonbrief.org
Read here: buff.ly/HWteg9K
Read here: buff.ly/HWteg9K
Overshoot: Exploring the implications of meeting 1.5C climate goal ‘from above’ - Carbon Brief
The first-ever international conference on the contentious topic of “overshoot” was held last week in...
buff.ly
October 8, 2025 at 3:58 PM
Last week, @ceciliakeating.carbonbrief.org and I attended the first-ever conference on climate "overshoot" in Vienna.
Here's our summary of the wide-ranging discussions. (Bearing in mind we were two journalists covering 8 conference themes...!)
Here's our summary of the wide-ranging discussions. (Bearing in mind we were two journalists covering 8 conference themes...!)
Reposted by Robert McSweeney
FACTCHECK: Claire Coutinho claims UK gas power only costs £55/MWh…
…but she is ignoring a few small details:
🤫 Gas prices always rise in winter
🤫 Gas plants cost money to build
🤫 CO2 causes economic damages
THREAD with receipts
1/8
…but she is ignoring a few small details:
🤫 Gas prices always rise in winter
🤫 Gas plants cost money to build
🤫 CO2 causes economic damages
THREAD with receipts
1/8
October 8, 2025 at 3:26 PM
FACTCHECK: Claire Coutinho claims UK gas power only costs £55/MWh…
…but she is ignoring a few small details:
🤫 Gas prices always rise in winter
🤫 Gas plants cost money to build
🤫 CO2 causes economic damages
THREAD with receipts
1/8
…but she is ignoring a few small details:
🤫 Gas prices always rise in winter
🤫 Gas plants cost money to build
🤫 CO2 causes economic damages
THREAD with receipts
1/8
Reposted by Robert McSweeney
Yet more embarrassment for the Times, which has printed a ludicrous – and almost certainly false – line about windfarms being “dismantled” near Trump’s Scottish golf course
But why pick up the phone, as I did, when you can print nudge-nudge rumours instead?
1/
But why pick up the phone, as I did, when you can print nudge-nudge rumours instead?
1/
September 19, 2025 at 1:36 PM
Yet more embarrassment for the Times, which has printed a ludicrous – and almost certainly false – line about windfarms being “dismantled” near Trump’s Scottish golf course
But why pick up the phone, as I did, when you can print nudge-nudge rumours instead?
1/
But why pick up the phone, as I did, when you can print nudge-nudge rumours instead?
1/
Really interesting guest post from @markengland.bsky.social unpacking why Arctic sea ice loss has slowed and how "climate models clearly show that such periods are expected parts of climate variability" ⬇️
NEW – Guest post: Why the recent slowdown in Arctic sea ice loss is only temporary | @markengland.bsky.social
Read here: buff.ly/eASA2sG
Read here: buff.ly/eASA2sG
Guest post: Why the recent slowdown in Arctic sea ice loss is only temporary - Carbon Brief
Observations reveal that Arctic sea ice extent at the end of summer has halved, since satellite records began in the late 1970s.
buff.ly
August 19, 2025 at 10:10 AM
Really interesting guest post from @markengland.bsky.social unpacking why Arctic sea ice loss has slowed and how "climate models clearly show that such periods are expected parts of climate variability" ⬇️
Reposted by Robert McSweeney
NEW – Factcheck: Trump’s climate report includes more than 100 false or misleading claims | @ayeshatandon.carbonbrief.org @leohickman.carbonbrief.org @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org @tomoprater.carbonbrief.org
Read here: buff.ly/AvcB7Aw
Read here: buff.ly/AvcB7Aw
August 14, 2025 at 3:48 PM
NEW – Factcheck: Trump’s climate report includes more than 100 false or misleading claims | @ayeshatandon.carbonbrief.org @leohickman.carbonbrief.org @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org @tomoprater.carbonbrief.org
Read here: buff.ly/AvcB7Aw
Read here: buff.ly/AvcB7Aw
Reposted by Robert McSweeney
NEW – Media reaction: The 2025 Texas floods and the role of climate change
✍️ @joshgabbatiss.bsky.social @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org
Read here ⬇️
www.carbonbrief.org/media-reacti...
✍️ @joshgabbatiss.bsky.social @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org
Read here ⬇️
www.carbonbrief.org/media-reacti...
Media reaction: The 2025 Texas floods and the role of climate change - Carbon Brief
At least 120 people have died after a devastating flash flood swept through homes and...
buff.ly
July 10, 2025 at 4:31 PM
NEW – Media reaction: The 2025 Texas floods and the role of climate change
✍️ @joshgabbatiss.bsky.social @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org
Read here ⬇️
www.carbonbrief.org/media-reacti...
✍️ @joshgabbatiss.bsky.social @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org
Read here ⬇️
www.carbonbrief.org/media-reacti...
Reposted by Robert McSweeney
MEDIA STUDIES: How the Times bungled its coverage of the OBR report on climate change & UK govt debt
Yesterday's newspaper reported a major shift: "The OBR now thinks…net-zero will have a far more damaging impact on borrowing…"
In fact, the OBR had said the opposite!
1/6
Yesterday's newspaper reported a major shift: "The OBR now thinks…net-zero will have a far more damaging impact on borrowing…"
In fact, the OBR had said the opposite!
1/6
July 10, 2025 at 9:28 AM
MEDIA STUDIES: How the Times bungled its coverage of the OBR report on climate change & UK govt debt
Yesterday's newspaper reported a major shift: "The OBR now thinks…net-zero will have a far more damaging impact on borrowing…"
In fact, the OBR had said the opposite!
1/6
Yesterday's newspaper reported a major shift: "The OBR now thinks…net-zero will have a far more damaging impact on borrowing…"
In fact, the OBR had said the opposite!
1/6
Reposted by Robert McSweeney
NEW – Experts: Which climate tipping point is the most concerning? | @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org
Read here: buff.ly/LkitgK7
Read here: buff.ly/LkitgK7
July 9, 2025 at 4:26 PM
NEW – Experts: Which climate tipping point is the most concerning? | @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org
Read here: buff.ly/LkitgK7
Read here: buff.ly/LkitgK7
Reposted by Robert McSweeney
NEW: Getting to net-zero will be much cheaper than thought for the UK – and unchecked global warming far more costly, says OBR
Quick piece / thread with 4 key charts showing, yet again, why climate action is far less costly than inaction
🧵
www.carbonbrief.org/...
1/6
Quick piece / thread with 4 key charts showing, yet again, why climate action is far less costly than inaction
🧵
www.carbonbrief.org/...
1/6
July 8, 2025 at 4:38 PM
NEW: Getting to net-zero will be much cheaper than thought for the UK – and unchecked global warming far more costly, says OBR
Quick piece / thread with 4 key charts showing, yet again, why climate action is far less costly than inaction
🧵
www.carbonbrief.org/...
1/6
Quick piece / thread with 4 key charts showing, yet again, why climate action is far less costly than inaction
🧵
www.carbonbrief.org/...
1/6
Carbon Brief was in Exeter last week for the Global Tipping Points conference.
There was a lot packed in to the 4-day event and we've summarised some of the talks and talking points here ⬇️
There was a lot packed in to the 4-day event and we've summarised some of the talks and talking points here ⬇️
NEW – Tipping points: Window to avoid irreversible climate impacts is ‘rapidly closing’ | @ceciliakeating.carbonbrief.org @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org @gsiexeter.bsky.social @pik-potsdam.bsky.social
Read here: buff.ly/ECWvN3z
Read here: buff.ly/ECWvN3z
July 8, 2025 at 6:31 PM
Carbon Brief was in Exeter last week for the Global Tipping Points conference.
There was a lot packed in to the 4-day event and we've summarised some of the talks and talking points here ⬇️
There was a lot packed in to the 4-day event and we've summarised some of the talks and talking points here ⬇️
Reposted by Robert McSweeney
What’s happened this week in climate change?
DeBriefed | Trump ‘megabill’ guts clean energy; Europe’s record heat; Scientists discuss ‘most worrying’ tipping points
✍️ @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org @ceciliakeating.carbonbrief.org
➡️ buff.ly/4G49jHj
DeBriefed | Trump ‘megabill’ guts clean energy; Europe’s record heat; Scientists discuss ‘most worrying’ tipping points
✍️ @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org @ceciliakeating.carbonbrief.org
➡️ buff.ly/4G49jHj
July 4, 2025 at 4:25 PM
What’s happened this week in climate change?
DeBriefed | Trump ‘megabill’ guts clean energy; Europe’s record heat; Scientists discuss ‘most worrying’ tipping points
✍️ @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org @ceciliakeating.carbonbrief.org
➡️ buff.ly/4G49jHj
DeBriefed | Trump ‘megabill’ guts clean energy; Europe’s record heat; Scientists discuss ‘most worrying’ tipping points
✍️ @rtmcswee.carbonbrief.org @ayeshatandon.carbonbrief.org @ceciliakeating.carbonbrief.org
➡️ buff.ly/4G49jHj
Reposted by Robert McSweeney
NEW – Chart: Trump’s ‘big beautiful bill’ blows US emissions goal by 7bn tonnes | @joshgabbatiss.bsky.social Ho Woo Nam
Read here: buff.ly/l700teP
Read here: buff.ly/l700teP
July 4, 2025 at 4:06 PM
NEW – Chart: Trump’s ‘big beautiful bill’ blows US emissions goal by 7bn tonnes | @joshgabbatiss.bsky.social Ho Woo Nam
Read here: buff.ly/l700teP
Read here: buff.ly/l700teP
Reposted by Robert McSweeney
NEW
Nigel Topping chosen as new chair of @thecccuk.bsky.social, pending formalities
Will bring experience from business world & UN climate talks to the role
Follows years-long delay after former Tory minister Lord Deben quit as chair and @piersforster.bsky.social steered ship in interim capacity
Nigel Topping chosen as new chair of @thecccuk.bsky.social, pending formalities
Will bring experience from business world & UN climate talks to the role
Follows years-long delay after former Tory minister Lord Deben quit as chair and @piersforster.bsky.social steered ship in interim capacity
July 4, 2025 at 11:46 AM
NEW
Nigel Topping chosen as new chair of @thecccuk.bsky.social, pending formalities
Will bring experience from business world & UN climate talks to the role
Follows years-long delay after former Tory minister Lord Deben quit as chair and @piersforster.bsky.social steered ship in interim capacity
Nigel Topping chosen as new chair of @thecccuk.bsky.social, pending formalities
Will bring experience from business world & UN climate talks to the role
Follows years-long delay after former Tory minister Lord Deben quit as chair and @piersforster.bsky.social steered ship in interim capacity
Reposted by Robert McSweeney
NASA scientists will apparently no longer be able to read @nature.com at their jobs, as the Trump administration has canceled all subscriptions to Springer Nature journals, per the agency. (1/3) 🧵
Received one more - this time from NASA
“NASA sent a notification to Springer Nature stating the agency was cancelling its subscriptions. Our engineers and scientists will still have access to NASA mission data shared with their journals, as well as have access to many other scientific journals.”
“NASA sent a notification to Springer Nature stating the agency was cancelling its subscriptions. Our engineers and scientists will still have access to NASA mission data shared with their journals, as well as have access to many other scientific journals.”
June 30, 2025 at 10:47 PM
NASA scientists will apparently no longer be able to read @nature.com at their jobs, as the Trump administration has canceled all subscriptions to Springer Nature journals, per the agency. (1/3) 🧵
June was England's warmest on record and the UK's second warmest, according to the @metoffice.gov.uk
www.metoffice.gov.uk/about-us/new...
www.metoffice.gov.uk/about-us/new...
July 1, 2025 at 2:05 PM
June was England's warmest on record and the UK's second warmest, according to the @metoffice.gov.uk
www.metoffice.gov.uk/about-us/new...
www.metoffice.gov.uk/about-us/new...
More net-zero misinformation in the Daily Telegraph.
It claims that a proposed scheme to put the cost of recycling onto packaging producers, rather than local councils, is a “net-zero glass tax”.
It is about waste management, not net-zero.
Somehow, this made it onto the frontpage 🤦
It claims that a proposed scheme to put the cost of recycling onto packaging producers, rather than local councils, is a “net-zero glass tax”.
It is about waste management, not net-zero.
Somehow, this made it onto the frontpage 🤦
June 27, 2025 at 9:35 AM
More net-zero misinformation in the Daily Telegraph.
It claims that a proposed scheme to put the cost of recycling onto packaging producers, rather than local councils, is a “net-zero glass tax”.
It is about waste management, not net-zero.
Somehow, this made it onto the frontpage 🤦
It claims that a proposed scheme to put the cost of recycling onto packaging producers, rather than local councils, is a “net-zero glass tax”.
It is about waste management, not net-zero.
Somehow, this made it onto the frontpage 🤦
Reposted by Robert McSweeney
NEW: UK climate advisers now "more optimistic" net-zero goals can be met
🎯Net-zero "possible" + "good for economy"
📉CO2 halved vs 1990
📈More "credible" policies
🚘🏡EV/heat pumps soaring
But…
⚡"Critical" to cut power prices
✈️Flight CO2 "risk"
www.carbonbrief.org/...
1/9
🎯Net-zero "possible" + "good for economy"
📉CO2 halved vs 1990
📈More "credible" policies
🚘🏡EV/heat pumps soaring
But…
⚡"Critical" to cut power prices
✈️Flight CO2 "risk"
www.carbonbrief.org/...
1/9
June 25, 2025 at 7:48 AM
NEW: UK climate advisers now "more optimistic" net-zero goals can be met
🎯Net-zero "possible" + "good for economy"
📉CO2 halved vs 1990
📈More "credible" policies
🚘🏡EV/heat pumps soaring
But…
⚡"Critical" to cut power prices
✈️Flight CO2 "risk"
www.carbonbrief.org/...
1/9
🎯Net-zero "possible" + "good for economy"
📉CO2 halved vs 1990
📈More "credible" policies
🚘🏡EV/heat pumps soaring
But…
⚡"Critical" to cut power prices
✈️Flight CO2 "risk"
www.carbonbrief.org/...
1/9
How do you account for volcanic eruptions in climate projections when you don't know when and where they will occur?
This new @carbonbrief.org guest post sets out a new approach:
This new @carbonbrief.org guest post sets out a new approach:
NEW – Guest post: Investigating how volcanic eruptions can affect climate projections | Dr May Chim, Dr Thomas J Aubry @cjsmith.be Prof Anja Schmidt
Read here: buff.ly/P4ZH3OE
Read here: buff.ly/P4ZH3OE
June 24, 2025 at 8:19 AM
How do you account for volcanic eruptions in climate projections when you don't know when and where they will occur?
This new @carbonbrief.org guest post sets out a new approach:
This new @carbonbrief.org guest post sets out a new approach:
New guest post on how 60% of the CO2 being released from the world's river rivers is coming from "ancient" sources, which were long thought to be stable.
It is a "warning sign that human activities, especially climate change, could intensify the release of carbon to the atmosphere via rivers".
It is a "warning sign that human activities, especially climate change, could intensify the release of carbon to the atmosphere via rivers".
NEW – Guest post: How the world’s rivers are releasing billions of tonnes of ‘ancient’ carbon | @joshfdean.bsky.social @profbobhilton.bsky.social
Read here: buff.ly/QwWlF6N
Read here: buff.ly/QwWlF6N
June 19, 2025 at 1:47 PM
New guest post on how 60% of the CO2 being released from the world's river rivers is coming from "ancient" sources, which were long thought to be stable.
It is a "warning sign that human activities, especially climate change, could intensify the release of carbon to the atmosphere via rivers".
It is a "warning sign that human activities, especially climate change, could intensify the release of carbon to the atmosphere via rivers".
Reposted by Robert McSweeney
We don’t know how close we are to triggering an Atlantic Ocean circulation #AMOC breakdown - but now we know a lot more about what it would mean for extreme temperatures in Europe. Good @carbonbrief.org piece on a new study just out by the Dutch colleagues! 🌊
www.carbonbrief.org/ocean-curren...
www.carbonbrief.org/ocean-curren...
Ocean current ‘collapse’ could trigger ‘profound cooling’ in northern Europe – even with global warming - Carbon Brief
A “collapse” of key Atlantic ocean currents would cause winter temperatures to plunge across northern Europe, overriding the warming driven by human activity.
www.carbonbrief.org
June 11, 2025 at 3:28 PM
We don’t know how close we are to triggering an Atlantic Ocean circulation #AMOC breakdown - but now we know a lot more about what it would mean for extreme temperatures in Europe. Good @carbonbrief.org piece on a new study just out by the Dutch colleagues! 🌊
www.carbonbrief.org/ocean-curren...
www.carbonbrief.org/ocean-curren...
This is a great new explainer from @hausfath.bsky.social on how air pollution affects the climate. It includes specific analysis on China's clean-air measures and new shipping rules:
I just published an explainer on aerosols and their role in the climate that I've been working on for the past few months! It includes both how aerosols work, how emissions have changed, and how thats driven recent warming: www.carbonbrief.org/...
June 11, 2025 at 10:02 AM
This is a great new explainer from @hausfath.bsky.social on how air pollution affects the climate. It includes specific analysis on China's clean-air measures and new shipping rules:
Reposted by Robert McSweeney
What a (some might say cynical) journey the latest chairman of Reform UK has been on when it comes to his denial of climate change!
In 2017, he tweeted a link to this article in Time...
time.com/4931586/irma...
In 2017, he tweeted a link to this article in Time...
time.com/4931586/irma...
June 10, 2025 at 1:52 PM
What a (some might say cynical) journey the latest chairman of Reform UK has been on when it comes to his denial of climate change!
In 2017, he tweeted a link to this article in Time...
time.com/4931586/irma...
In 2017, he tweeted a link to this article in Time...
time.com/4931586/irma...