David Roberts Pessimism Piece

David Roberts got a lot of attention for a recent post saying that global warming is a difficult problem.

I have a couple of comments.

For one, I was surprised to read this:

The IPCC scenarios that come in below 2°C require BECCS to remove between 2 and 10 gigatons of CO2 a year from the atmosphere by 2050. By way of comparison, all the world’s oceans combined absorb about 9 gigatons a year; all the world’s terrestrial carbon sinks combined absorb about 10 gigatons a year. That’s between 5 and 25 percent of total 2010 CO2 emissions.

At first sight, I read what the grammar indicates for this passage. That is, the world’s oceans and terrestrial carbon sinks only absorb between 5 and 25 percent of total 2010 CO2 emissions.

Of course, that doesn’t make any sense. I was wondering if there isn’t some kind of mistake.

The real figure is, according to GlobalCarbonProject, more like 56 percent. For the average between 2004 and 2013, 44 percent of emissions accumulated in the atmosphere, 26 percent in the oceans and 30 percent on land carbon sinks.

I was wondering how someone who makes his living at writing about climate issues could get such a point wrong. Then I noticed that the “between 5 and 25 percent” is talking about the “between 2 and 10 gigatons of CO2 possibly removed by BECCS” part, not about the ocean and terrestrial sinks part.

This confusion could have been avoided if Roberts had written “Scenario BECCS removals are only between 5 and 25 percent of total 2010 emissions.”

Anyway, this was an excellent occasion to find out the real numbers. Again, according to GlobalCarbonProject, less than half of human CO2 emissions stays in the atmosphere and more than half goes into land and ocean sinks.


I agree with the assessment that global warming is a difficult problem. I don’t agree with the pessimism.

That’s because I believe in further exponential explosive growth of renewable energy. And because I think Phaseout Profit Theory could speed up things substantially.


Published by kflenz

Professor at Aoyama Gakuin University, Tokyo. Author of Lenz Blog (since 2003, lenzblog.com).

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: