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
About 2400 billion tonnes of CO2 (GtCO2) have already been emitted between the years 1850 and the end of 2019 (2/n)
I then add global emissions pathways consistent with current policies, and various interpretations of country pledges (called NDCs, or nationally determined contributions) from the latest update of the @UNEP#EmissionsGap Report 2021. (3/n)
As it stands today, under the most optimistic pathway of #COP26 pledges and announcements, the carbon budget for keeping warming to 1.5°C with 50% or higher chance will be exhausted by the early 2030s.
(6/n)
What can be done?
What about increasing near-term ambition to ensure emissions are halved by 2030?
This postpones the date and is critical to keep 1.5°C alive, but action (and emissions reductions) cannot end there.
(7/n)
Only when further combined with the achievement of #NetZero CO2 emissions by 2050 can total CO2 emissions be kept to within a 1.5°C carbon budget.
Even then the likelihood that warming is kept to 1.5°C is barely about 50%. Not great, but keeping 1.5°C alive!
(8/n)
Uncertainties in past emissions, interpretations of pledges, and the size of carbon budgets do not change the core message that ambition needs to be increased to keep 1.5°C alive. (end)
With a big thank you to @RobinLamboll for helping to calculate these pathways!
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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)
I wrote a long thread on 10 guidelines that we published earlier this year in the scientific journal @Nature (with Annette Cowie, @ReisingerAndy and @Oliver_Geden) (3/n)
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)
The latest @UNEP#EmissionsGap Report finds new and updated Nationally Determined Contributions only take 7.5% off predicted 2030 emissions compared to previous commitments. Reductions of 30% are needed to stay on the least-cost pathway for 2°C and 55% for 1.5°C. (3/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)
Did you notice in the previous figure: a heat extreme that our great-grandparents would have experienced once in their lifetime, will occur about once every 4 years in a 2°C warmer world. It will be the norm in a 4°C warmer world.
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)
The scientific basis underlying a carbon budget is our robust scientific understanding that global warming is near-linearly proportional to the total amount of CO2 we ever emit as a society.
This is shown in Fig. SPM10, both for the past and future projections. (3/n)