Thread by @Peters_Glen

THREAD

CO₂ emissions have declined (2005-2015) in 18 advanced economies (US & EU countries). What have they done differently to other countries & what can other countries learn?

1/ rdcu.be/bor0g

First, a preemptive strike. No, it is not because they outsourced their emissions.

In the 2000's, when China was growing rapidly, this was an issue. Since the Global Financial Crisis, this is not a problem. Consumption emissions are declining (fast)

2/ agupubs.onlinelibrary.wiley.com/doi/full/10.10…

The drivers of the decline vary by country, but three elements are consistent:
* A decline in total energy use (orange)
* An increase in non-fossil energy (green)
(other factors can be important in single countries)
* A plethora of energy & climate policies (not shown)
3/

The factors we looked at:
* Energy use
* Share of fossil in final energy
* Fossil utilization (primary per final energy)
* CO₂ emissions in final energy
* International trade ("outsourcing")
4/

The drivers in each country are slightly different. Examples:
* The US had a big shift from coal to gas, solar, wind
* Sweden had a big shift to non-fossil energy
* UK had a decrease in energy use
* and so on...

See the SI. 5/ nature.com/articles/s4155…

We compared against 2 control groups (middle, right):
* Growth in energy use has slowed in the group of 18 (orange), but slow GDP growth is certainly a factor (grey)
* Fossil share has declined in the group of 18
* Each group had different mixes of energy & climate policies
6/

How does the data (left) compare to IAMs (right)?
* IAMs general mitigate by decarbonizing (eg, more renewables)
* IAMs had more rapid growth in energy use
* IAMs had too high economic growth (see previous point)

Are IAMs too rigid in terms of energy use?

7/

Is this all too heavy? Read the short summaries:
* theconversation.com/carbon-emissio…
* theconversation.com/eighteen-count…
* The paper (for free) rdcu.be/bor0g
* The Supplementary Information nature.com/articles/s4155…
* Or ask questions (nicely)
8/8