With every year passing global warming progresses. 🌍🔥

@IPCC_CH reports provide the most authoritative climate assessments but only in 5-7 year intervals.

To fill this gap over 50 scientist annually update key indicators of global climate change.

Latest update out now, a🧵 In 2021, the @IPCC_CH climate report assessed the state of the climate system and the “unequivocal” role of humans in changing it.
Since then, CO2 emissions and global warming have continued and up-to-date and trustworthy climate information is more important than ever

Breaking news on #CO2 📢🔥🌍
The new @gcarbonproject emissions numbers are out with an analysis by @CarbonBrief

What do the numbers tell us?
Spoiler alert: they are quite the party pooper for prospects of global peaking 🥳💩😢 (1) Global CO2 emissions from fossil fuels and the production of cement increased yet another 1.1% since 2022, reaching their highest level yet.
36.8 billion tons of CO2 in 2023!

Total CO2 emissions that include land use increased by ca. 0.5%, a tie with the 2019 record (2)

Two quotes by two scientists have caused a bit of confusion. 👇

I am one of them.
So let me explain what I'm referring to here. (1) @KarlMathiesen

https://twitter.com/KarlMathiesen/status/1731385461732495453

The latest @IPCC_CH mitigation report shows different ways in which warming can be kept to (close to) 1.5°C.
See the light-blue range in the figure below which shows global GHG emissions. (2)

Hot off the press - new climate research 🚨🌍🔥
Will warming stop once we reach net zero CO2 emissions?

Open-access publication @FrontiersIn assessing what we know and don't know about whether warming will stop once net zero CO2 emissions are reached. /1
frontiersin.org/journals/scien… With #NetZero targets established as key components of international and national climate policy, it becomes ever more pertinent to closely understand what reaching net-zero emissions will deliver and what it doesn't. /2

iopscience.iop.org/article/10.108…

Today, the @esabcc_eu published its advice for the @EU_Commission's #2040ClimateTarget proposal and accompanying #GreenhouseGasEmissionsBudget

Interested in how the advice was developed?
Here’s a slightly longer explainer of the underlying report

🧵

climate-advisory-board.europa.eu/reports-and-pu…
1/n The Advisory Board recommends the EU to take up a 2040 emissions reduction target of 90–95% compared to 1990 to keep the EU’s GHG budget to within 11 to 14 Gt CO2e between 2030 and 2050. #2040ClimateTarget #GreenhouseGasEmissionsBudget

Where do these numbers come from?

2/n

In 2021, the European Climate Law created the European Scientific Advisory Board on Climate Change @esabcc_eu and tasked it to inform the EU’s #2040ClimateTarget and 2030-2050 greenhouse gas (GHG) budget.

Today, @esabcc_eu published its advice.
Here’s the short version 🧵1/n The Advisory Board recommends the @EU_Commission to take up:

a 2040 emissions reduction target of 90–95% compared to 1990

to keep the EU’s GHG budget to within 11 to 14 Gt CO2e between 2030 and 2050.
2/n

Where are global emissions heading and where should they be going to keep #globalwarming well below 2C and 1.5C?

Today, @UNEP released the 2022 #emissionsgap report.

A look at the key messages

but caution, not much good news ahead 🧵/1 Countries’ new and updated pledges (NDCs) submitted since COP26 reduce projected global GHG emissions in 2030 by only 0.5 gigatons of CO2 equivalent (GtCO2e) compared with projections based on pledges at the time of COP26.
Some pledges result in even higher emissions /2

Excellent conversation going on about how media messaging following the @IPCC_CH 1.5 report sating we have "12 years left" until [your favorite climate pandemonium term] has been a disservice to science communication, and is damaging to date 👇
(1/n) @guardian @Fridays4future

https://twitter.com/bobkopp/status/1490665369698242560

As one of the coordinating authors of the report I can only wholeheartedly agree with @bobkopp @PFriedling @theresphysics and others that this is a dangerous misrepresentation of the report's assessment and messages.

Let me explain why

(2/n)

Two years ago - we published a new scenario logic to avoid risky and unfair climate change scenarios in @Nature.

Yesterday, two new studies in @NatureClimate apply this logic and find that avoiding overshoot is the right thing to do both to reduce risks and overall costs.
/1 Our initial @Nature study highlighted that focussing on a target in 2100 and not caring about what happens until then results in scenarios that suggest the best way to meet a target is to plan to first miss it.

Weird, irresponsible, and arguably wrong.
/2
nature.com/articles/s4158…

#COP26 is concluding after two years of work with some important decisions.

Some highlights of those areas I have followed most closely:
1) science
2) increased ambition
3) the Paris Rulebook

Some quick reflections (1/n) 1) science
For the first time ever, scientific evidence is included as a key framing of the various COP decisions. This is historic and includes strong messages on the scientific requirements as identified by @IPCC_CH to keep warming to 1.5C.
(2/n)

New #COP26 analysis: 🚨🌡️🌍
Is COP26 on track to keep 1.5°C alive?

Here I connect the dots between findings of the most recent scientific reports and look at what current pledges mean for carbon budgets limiting warming to 1.5C

(1/n) I start with historical CO2 emissions from the Global Carbon Project @gcarbonproject as assessed in the latest @IPCC_CH #AR6 #ClimateReport

About 2400 billion tonnes of CO2 (GtCO2) have already been emitted between the years 1850 and the end of 2019 (2/n)

Often misunderstood, even by climate change scholars like @jasonhickel, a 2050 #netzero greenhouse gas emissions is not the global average!

It is two decades earlier than the global average in 1.5C pathways. (1/2)

https://twitter.com/jasonhickel/status/1455527606539984917

1.5C pathways with no or limited overshoot reach #netzero CO2 emissions by 2050, and #netzero greenhouse gas emissions around 2070.

A target of #netzero GHG by 2050, like the EU, US, UK, and others, is thus well in advance of the global average.

What makes a good #NetZero pledge?

Many things but picking three:
1) focus on reductions then removals (& separate them out)
2) justify how it is fair and adequate
3) have a clear plan showing how reductions are achieved in the near term (1/n)
bbc.com/future/article… @BBC_Future Together with @CFyson from @climateactiontr and @katecullen_ we comment on how #NetZero targets can help, but also on how there is a series of boxes to be ticked by before any #NetZero target becomes a solid and ambitious contribution to tackling the #ClimateCrisis. (2/n)

The Heat is On🔥🌍
A world of climate promises not yet delivered

Today we’ve publish the @UNEP #EmissionsGap report

Good news:
we are doing increasingly better closing in on 2°C
Bad news:
it is still far from meeting the goals of the #ParisAgreement

A short thread (1/n) The @UNEP #emissionsgap report takes stock of current pledges of countries and compares them to where emissions emissions should be going to limit warming to 1.5°C or 2°C.

The difference is called the emissions gap.
(2/n)

Visuals in the latest #IPCCReport are a marvel I cannot stop talking about!

Here's part 2 of my overview of @IPCC_CH AR6 SPM visuals.

Kudos once again to @angelamorelli @tomhal99 @jordanharold and @MelichatGo for helping to visualize our insights (1/n) After yesterday, we now landed on changes in extremes🌡️⛈️🥵🧺!

And although I don't like to pick favorites, I do like this visual very much.

Too big for a single tweet, this one shows how hot extremes over land change compared to when our great-grandparents were alive. (2/n)

After the first bang of the @IPCC_CH AR6 report, it's time to look at my favorite part of the report:
visuals in the SPM.

It was a privilege to work with a team of #dataviz and information design experts @angelamorelli @tomhal99 @jordanharold on these visuals
(1/n) The first visual shows us that human influence has warmed the climate at a rate unprecedented in at least 2000 years.

I really like how it contrasts the climate our societies were used to during their development with the evidence that we are responsible.
(2/n)

Carbon budgets tell us how much CO2 we can still emit while keeping warming below specific limits.

The latest @IPCC_CH report provides updated estimates of these budgets.

Here’s an insider's view with a deep dive looking at how they have changed since previous reports. (1/n) I have been involved in the estimation of carbon budgets since the IPCC Fifth Assessment Report in early 2010s.

And since the first IPCC estimates published in 2013, we have learned a lot and have gotten much better at estimating remaining carbon budgets. (2/n)

EXPLAINER: new projections for the next 5 years by @metoffice and @WMO indicate that there's a high chance that one of these years is 1.5°C warmer than average preindustrial levels.

What does this mean?
A short explainer.

#ClimateAction

(1/n)
hadleyserver.metoffice.gov.uk/wmolc/ The 1.5C level in the @metoffice announcement should not be confused with the 1.5C limit in the Paris Agreement.

The Paris targets refer to global warming - that is, the temperature increase of our planet once we smooth out important year-to-year variations (see👇)
(2/n)

*Great NEWS*
Today @IEA published its #NetZero2050Roadmap-a scenario that brings global CO2 emissions down to #NetZero by 2050.

This is the first time IEA presents a detailed picture of how the global economy can be transformed in line with 1.5C (1/n)

iea.org/reports/net-ze… A detailed look at the report shows that @IEA has done a thorough job.

Modelling choices underpinning the pathway are well argued, reliance on speculative technologies is limited, and the carbon budget is in line with the most ambitious pathways available in the literature (2/n)

Today's news from Australia's @Science_Academy latest climate report: "limiting climate change to 1.5°C is now virtually impossible"

I'm quite confused by their finding & scientific evidence backing it up is questionable at best.
#auspol

- a thread (1/n)
smh.com.au/environment/cl… The @Science_Academy's analysis starts from carbon budgets reported in @IPCC_CH's 1.5°C Special Report's Table 2.2 (orig. below).

Then makes adjustments & updates.

Having had the pleasure to compile Table 2.2 for #SR15, let's compare and try to make sense of the numbers

(2/n)

How can #NetZero targets be made rigorous, fair and transparent?

We published 10 guidelines that can help

Details are buried in the supplement of our @nature comment.

Here I'll be going through them, one per day

@COP26 @topnigel @PEspinosaC

(1/n)

https://twitter.com/JoeriRogelj/status/1371749405355864064

The supplement contains an overview table (👇) and a detailed set of guidelines for #NetZero targets

They cover:
I. Scope (of target)
II. Adequacy & Fairness
III. Long term roadmap

It's a long list - so let's get through it one day at a time

(2/n)

nature.com/articles/d4158…