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Apr 22, 2014
I really enjoy posting fun stuff here.  But this is serious.

Steve Easterbrook just finished writing a series of important posts on Azimuth, summarizing part of the IPCC report on climate change.  Here's a short version of his last post.  Pay attention!

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To stay below 2°C of warming, most fossil fuels must stay buried in the ground.

Perhaps the most profound advance since the previous IPCC report is a characterization of our global carbon budget. This is based on a finding that has emerged strongly from a number of studies in the last few years: the expected temperature change has a simple linear relationship with cumulative CO2 emissions since the beginning of the industrial era.

The chart is hard to follow, but the main idea is this: whatever we do, the results tend to lie on a straight line on this graph. You do get a slightly different slope in one case, “1% percent CO2 increase per year", where only CO2 rises - and much more slowly than it has over the last few decades.  But all the more realistic scenarios lie in the orange band, and all have about the same slope.

This is a useful insight, because it means that for any target ceiling for temperature rise - like the UN’s commitment to not allow warming to rise more than 2°C above pre-industrial levels - we can easily estimate the total amount of carbon we can spew into the atmosphere:

• To give us a one third (33%) chance of staying below 2°C of warming over pre-industrial levels, we cannot ever emit more than 880 gigatonnes of carbon.

• To give us a 50% chance, we cannot ever emit more than 840 gigatonnes of carbon.

• To give us a 66% chance, we cannot ever emit more than 800 gigatonnes of carbon.

Since the beginning of industrialization, we have already emitted a little more than 500 gigatonnes. So, our remaining budget is somewhere between 300 and 400 gigatonnes of carbon.

Existing known fossil fuel reserves are enough to release at least 1000 gigatonnes. New discoveries and unconventional sources will likely more than double this.

That leads to one conclusion:

Most of our remaining carbon reserves must never reach the atmosphere.

We’ve never done that before. There is no political or economic system anywhere in the world currently that can persuade an energy company to leave a valuable fossil fuel resource untapped. There is no government in the world that has demonstrated the ability to forgo the economic wealth from natural resource extraction, for the good of the planet as a whole. We’re lacking both the political will and the political institutions to achieve this. Finding a way to achieve this presents us with a challenge far bigger than we ever imagined.

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Red Steve's whole series of posts starting here:

http://johncarlosbaez.wordpress.com/2014/04/07/what-does-the-new-ipcc-report-say-about-climate-change-part-1/

Each post summarizes a key finding of the IPCC Working Group 1 report on climate change, released last year.  These findings are:

1. The warming is unequivocal.

2. Humans caused the majority of it.

3. The warming is largely irreversible.

4. Most of the heat is going into the oceans.

5. Current rates of ocean acidification are unprecedented.

6. We have to choose which future we want very soon.

7.  To stay below 2°C of warming, the world must become carbon negative.

8.  To stay below 2°C of warming, most fossil fuels must stay buried in the ground.

The graph here is explained in Steve's 8th post:

http://johncarlosbaez.wordpress.com/2014/04/22/what-does-the-new-ipcc-report-say-about-climate-change-part-8/

and in more detail on page 28 of the Summary for Policymakers:

http://www.climatechange2013.org/images/report/WG1AR5_SPM_FINAL.pdf

and page 15 of the Technical Summary Supplementary Material:

http://www.climatechange2013.org/images/report/WG1AR5_TSSM_FINAL.pdf
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