When plotting all scenarios in the #SR15 database, it looks like nuclear may have a rosy future. But a closer look shows it is a more complex picture... 1/6
Plotting the additional nuclear over the baseline scenario (scenario minus baseline) reveals:
* nuclear does not change much relative to the baseline in most scenarios
* nuclear has solid growth in some scenarios 2/6
It turns out that the scenarios with solid growth in nuclear come from two models GCAM & MESSAGE. Here are model & scenario combinations with highest nuclear growth (42 listed). This lifts the median & gives impression of a more positive future for nuclear. 3/
THREAD (on temperature, overshoot, & afforestation in #SR15)
In this thread I group a few nice (ie, unreadable) Twitter discussions on a few intriguing aspects of the Special Report on 1.5°C:
* What is "no overshoot"?
* What is "temperature"?
* Land impacts of afforestation? 1/
The SPM to the IPCC Special Report on 1.5°C highlighted 4 illustrative scenarios. This is fine. Three scenarios are called "no or limited overshoot". But, why are they grouped as "no or limited overshoot", & not as "no overshoot" or "limited overshoot"? 2/
(Aside: In Chapter 2, the illustrative scenarios are labelled LED, S1, S2, S3, in the Summary for Policy Makers they are labelled P1, P2, P3, P4) /2b
When I hear ppl saying that we need systems change and not culture change to address #climate breakdown, I think ppl overstate the ability of top down law reform to change culture. Law reform is not particularly effective and changing culture. 1/
Guess what - the 13th, 14th, and 15th amendments did not achieve the end of slavery, equality, or the right to vote for African Americans. Slave state culture maintained near total African servitude, inequality, and vote suppression for a century b/c it was in the culture. 2/
Prohibition was written into the constitution. People did not stop drinking b/c it was in the culture, and the temperance forces didn’t give resources to enforce prohibition b/c it drinking really didn’t affect them except philospophically. 3/
1/ Forget about coral reefs & polar bears. The difference between 1.5˚ and 2˚of warming is 60 million more people exposed to severe drought; millions more potentially exposed to flooding, 23% more of the world's population exposed to extreme heat. This stuff is real.
2/ For small-island states at risk of being wiped off the map, limiting warming to 1.5˚ was already "the ultimate compromise". "We knew that 1˚ would jeopardize our ability to live on these islands,” a Marshall Islands rep said. “Anything beyond 1.5 is simply uninhabitable.”
This is important, and it's of a piece. As clear as the #SR15 report was on the rapid physical transformation needed to avoid #climatebreakdown, it was almost silent on the political parameters of that transformation - but these are well researched. 1/?
As @TimmonsRoberts says, “It leaves readers and policy makers without tools to address the problem in the real world.”
So the big gap in #SR15 is one of covering the political realities surrounding climate change: these include the biggest barriers & best avenues for action. 2/?
That's quite a gap! Climate denial, as an action of the fossil fuel industry, has been wildly successful, weaponizing both scientific processes and media discourses. And divestment, extraction bans, legal actions have had arguably more success than techno-econ fixes. 3/?
ICYMI: A big week for #GreenBonds & climate finance, with the #SR15 reminding us of the urgency to scale up green investment. In this string we’ll point to some of the events & moments from around the world that we’ve captured since Monday.
We often hear tales about the disrupting/delaying/diluting tactics of "The Saudis" at UN climate change meetings.
It was the same last week at the IPCC meeting in S Korea when the #SR15 special report was finally approved by all the world's govts.
Here's my take...
Here's what AFP reported last Friday: "Oil giant Saudi Arabia is seeking to block adoption of a key UN climate change report unless a passage highlighting the inadequacy of national carbon-cutting pledges is removed or altered, multiple sources told AFP"
And here's AFP's follow-up story, once the report was approved on Sat: "The Saudis had objected to the inclusion of a passage emphasising the need for sharp reductions in the use of fossil fuels - Saudi Arabia's main export"...
A couple interesting notes from the IPCC #SR15 on what the 1.5C pathway means for electricity. Thread follows. Bear with me on the figures. The resolution in the report is crap and I couldn't find the underlying data to reproduce them, so I've annotated them. [1/5]
First clear thing is massive electrification. Electricity as % of final demand rises from ~20% to ~60% (!!) across all scenarios.
Different bars are temp scenarios decreasing in stringency from L to R:
<1.5C (blue) 1.5 low-OS (green) 1.5 hi-OS (orange)
<2 lo (red)
<2 hi (purple)
Second thing is emission intensity of electricity sector. Falling across all scenarios, but much quicker under 1.5C scenario (blue). Roughly zero across all scenarios by 2050.
With the outreach and analysis of @IPCC_CH#SR15 report underway, I could not resist trying to summarise the SPM in 19 #haiku, forever inspired by @climate_haiku. (Disclaimer: personal choices here, not representing the same balance as the full report...). "Introduction" (1/19)
The #IPCC#SR15 report says very little about solar #geoengineering, which is the main, but not only subject, of my book #ThePlanetRemade beyond saying that there is high agreement that a particular form of it could keep temperatures below 1.5C (Cross chapter box 10 in Chapter 4)
If the IPCC not going into this more seems an odd omission, given the topic, I think it is because a) the scientific understanding on solar #geoengineering, which obviously will never be complete, is still pretty sketchy in many respects (though not as sketchy as some may think)
b) the structure that the IPCC chose for the report (which was forced on it in part by the UNFCCC's mandate to it) did not allow it o assess solar #geoengineering's potential contribution in any of its scenarios
2/ A reminder: natural gas currently accounts for 20% of global energy emissions and is the world’s fastest growing fossil fuel. In the IEA’s current policies scenario, gas demand could increase by ~50% by 2040.
How far is this from a 1.5⁰C pathway?
3/ With coal, the IPCC message is simple: stop burning it. The IPCC pathways show a reduction in coal in primary energy use of 59-78% by 2030, compared to 2010. By 2050 it falls 73-97%.
Too lazy to read our 30 page Summary For Policy Makers and report? Well here it is in tweets @IPCC_CH (1/n) where n is likely greater than 10 and less than 30 - now trying to thread them together - #twitterincompetence : real thing is here ipcc.ch/report/sr15/
As always, the #peerreview effort by @IPCC_CH is Herculean. A couple hundred volunteer scientists read & cited 6,000+ studies to support conclusions w/ evidence. Responded to 42,001 comments in 3 rounds of review. The most robust process there is to establish scientific consensus
Now, this #SR15 report title is descriptive, but doesn't exactly roll off the tongue...
“Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate.”
That’s what would probably happen if we keep global emissions flat. It already gives a sense of how fast we should reduce emissons to stay below 1.5°C.
Even global warming of 1.5°C would result in more hot temperature extremes in most inhabited regions, heavier precipitation in several regions, drought and precipiation deficits in some regions. But less so than 2°C.
2. As we put it, in order to hold warming to 1.5C, "overall reductions in emissions in the next decade would probably need to be more than 1 billion tons per year, larger than the current emissions of all but a few of the very largest emitting countries." @brady_dennis
3. So, most of these countries. We'd have to cut emissions every year by more than most of these countries emit annually. That is the scale of what is being talked about.
1987: President of the Maldives: "We know, & yet we keep delaying action. The time for just talking is over."
1988: James Hanson testified "99% confidence"
1988: The #IPCC is born
1990: IPCC First Assessment Report (FAR)
1990: Alliance of Small Island States (AOSIS)
1992: UNFCCC "to prevent dangerous anthropogenic interference with the climate system"
1997: Kyoto Protocol
2007: Bali Road Map gives new hope
2008: A limit well below 1.5°C (Tuvalu, AOSIS)
2008: 1.5°C to stay alive
2009: Copenhagen Accord enshrined 2°C in climate politics