"[a]n economic recovery tilted towards green stimulus and reductions in fossil fuel investments, it is possible to avoid future warming of 0.3 °C by 2050."
The use of the word "tilted" implies are rather minor shift, but the "strong green stimulus" is actually a ~1.5°C pathway ("moderate" is a ~2°C pathway).
I thought 1.5°C required a transformation? Did #SR15 get it wrong?
2/
#SR15: "Pathways limiting global warming to 1.5°C with no or limited overshoot would require rapid and far-reaching transitions in energy, land, urban and infrastructure (including transport and buildings), and industrial systems (high confidence)"
Another issue I have with the framing is that I would think of "recovery" as being a short-burst (maximum a few years) of investment to achieve whatever objective ("recovery").
But, these "green stimulus" pathways are continuous investments to 2050. This is permanent change!
5/
Of course, we want permanent change, but I don't think this meshes so well with the term "recovery".
If I recover from being sick, does that mean I spend the rest of my life in intensive care?
I need to change my diet/lifestyle, permanently, not recover & return to normal?
6/
Current pledges put us on a path for 1.8°C or so in 2050, & if we follow a 1.5°C pathway, we shave off 0.3°C. This is still 0.3°C higher than where we are today (~1.2°C).
I think this is an important point to focus on, but the challenge is communicating these changes.
7/
The climate is a slow moving system, so deep mitigation (purple in top figure) leads to small & delayed changes in the temperature response (bottom figure).
This is my attempt to communicate the challenge, based on the SSP database (of course, too complex for lay audiences).
8/
Noting that the authors based the reference pathway on where we are heading (as opposed to the worst case RCP85-type pathway). This is the correct approach!
Using a RCP85-type pathway as a reference would make the benefits of mitigation ≫0.3°C...
Record high emissions means record high radiative forcing.
We have you covered, we also include aerosols (SO2, etc) & have done so for decades. Also shipping!
Short-lived aerosols are important, but should not distract from the drivers of change: greenhouse gas emissions!
2/
Most of the energy put into the system ends in the ocean (90%), so the Ocean Heat Content (OHC) has been increasing along with emissions and radiative forcing.
This also means the Earth Energy Imbalance is also increasing.
This question is ambiguous: "How high above pre-industrial levels do you think average global temperature will rise between now and 2100?"
* ...pre-industrial... between "now and 2100"?
* Where we are currently heading or where we could head? This is largely a policy question?
3/
One of the key arguments that Norway uses to continue oil & gas developments, is that under BAU it is expected that oil & gas production will decline in line with <2°C scenarios, even with continued investment.
Let's look closer at these projections & reality...
1/
Here is the projections from the 2003 report from the petroleum agency.
In reality (tweet 1) there was a dip around 2010, but production is now up around 250 million cubic again.
The forecast was totally & utterly WRONG!
2/
In 2011 there was a forecast for an increase in production to 2020, but then a decline. This is probably since they started to put the Johan Sverdrup field on the books.
The increase in production was way too low, again, they got it wrong.