ALSR
Thanks for #840
I manage to get to presentations by top economists (usually at the LSE) and often get a quick word with them afterwards and sometimes an email exchange. This led me to write “
Is Green Growth a Fantasy” which simplifies the Kaya Identity, looking at carbon emissions as (1)the carbon intensity of production in dollar terms times (2) the world's production i.e. the total of the world's GDPs.
Carbon emissions are still increasing – boosted somewhat by an increased population; reduced substantially by a lower Carbon Intensity but swamped by increased Personal Product, the GWP per person.
Some, if not most, policy makers say that “Green Growth” is possible – and an increase in production can be counter balanced by a much lower carbon intensity so that carbon emissions fall fast enough to avoid dangerous climate change. The questions are
1. Can the world decarbonise fast enough?
2. Is Green Growth a fantasy?
As a thought experiment (or reductio ad absurdum?), I assumed that carbon extraction from the atmosphere (e.g. BECCS) begins to work seriously after 2050. It's simple maths to find what rate of carbon reduction keeps within the remaining carbon budget until the world is saved by BECCS in 2050.
For the remaining carbon budget I had assumed 843 billion tonnes,. This required a carbon intensity reduction of 4% pa with no increase in personal consumption but 1% pa rise in population. Doing similar sums on 590 billion tonnes CO2e requires a rate of decarbonisation of 6% pa - or 7% pa on the assumption of a 1% rise in population.
PWC's Low Carbon Economy Index 2015 has on it's front page:
1.3% Annual fall in carbon intensity since 2000
6.3% Annual carbon intensity reduction needed for 2°C
The economists I hear at the LSE still seem to think green growth is possible.
If anyone has any idea how to get any economists to engage with this I'd like too know.
QUESTION 1 (That you have mostly answered on #841)
To get to the question, which I wanted to ask. This is: Have you or anyone here any background information on the Nature Climate Change Article?
I notice that Myles Allen is one of the authors. I had assumed he “erred on the side of least drama” because of
his views on methane and short term climate forcing agents and saying that hurricane Sandy was only a category 1 hurricane (true but!).
Have the "official climate scientists" got round to telling the whole story as it is known at present?
e.g.
Do they measure methane over 20 or 100 years?
Any missing or underestimated feedbacks?
QUESTION 2
I have read an excellent article in the Atlantic magazine
1491. This discusses the theory that the Amazon was mostly cultivated before European invasions that caused and enormous decline in population due to disease. The Amazon forest is basically an overgrown garden. This would have extracted CO2 and cooled the Earth. This seems almost plausible looking at ice-core CO2 readings.
Is this plausible? I do remember reports black death and plague affecting climate.