[MCN] Halting the heat at 2C: Renewables are a necessity, but not up to the job

[Lance Olsen]

The Economist  Nov 17 2017. 

https://www.economist.com/news/leaders/21731397-stopping-flow-carbon-dioxide-atmosphere-not-enough-it-has-be-sucked-out <https://www.economist.com/news/leaders/21731397-stopping-flow-carbon-dioxide-atmosphere-not-enough-it-has-be-sucked-out>

Excerpts
Fully 101 of the 116 models the Intergovernmental Panel on Climate Change uses to chart what lies ahead assume that carbon will be taken out of the air in order for the world to have a good chance of meeting the 2°C target. The total amount of CO2 to be soaked up by 2100 could be a staggering 810bn tonnes, as much as the world’s economy produces in 20 years at today’s rate (see article <http://www.economist.com/news/briefing/21731386-cutting-emissions-will-not-be-enough-keep-global-warming-check-greenhouse-gases-must-be>). 

Putting in place carbon-removal schemes of this magnitude would be an epic endeavour even if tried-and-tested techniques existed.

They do not. 

A few power stations and industrial facilities capture CO2 that would otherwise end up in the air and store it away underground, a practice known as carbon capture and storage. But this long-touted approach to cutting emissions still operates on only a very small scale, dealing with just a few tens of millions of tonnes of CO2 a year. And such schemes merely lower emissions; they do not reverse them.

What might? One option is to plant more forests (which act as a carbon sink) or to replace the deep-ploughing of fields with shallow tillage (which helps soils absorb and retain more CO2). Another is to apply carbon capture and storage to biomass-burning power plants, stashing the carbon sucked up by crops or trees burnt as fuel. Fancier ideas exist. Carbon could be seized directly from the air, using chemical filters, and stored. Or minerals could be ground up and sowed over land or sea, accelerating from aeons to years the natural weathering process that binds them to CO2 to form carbonate rocks.

Whether any of these technologies can do the job in time is unknown. All of them are very expensive and none is proven at scale. Persuading Earth’s swelling population to plant an India’s worth of new trees or crops to produce energy, as the climate simulations require, looks highly improbable. Changing agricultural practices would be cheaper, but scientists doubt that this would suck up enough CO2 even to offset the greenhouse gases released by farming. Direct air capture and enhanced weathering use less land, but both are costlier. Though renewable energy could profitably generate a fair share of the world’s electricity, nobody knows how to get rich simply by removing greenhouse gases.

If the market will not provide an incentive, governments could. The case for a proper price on carbon (this paper has favoured a tax) is strong. Its absence is one of the reasons carbon capture and storage has not taken off as a way of reducing emissions from fossil-fuel plants; the kit needed can double the price of electricity. Yet, setting a price high enough to encourage negative emissions would asphyxiate the economy.

In fact, taking carbon dioxide from the atmosphere is not an alternative to belching out less greenhouse gas. It is necessary in its own right. Unless policymakers take negative emissions seriously, the promises of Paris will ring ever more hollow.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"What we're understanding is that the human body is actually very sensitive to heat, and that suggests pretty much everybody's at risk,” 
said Camilo Mora, the paper's lead author. "It's not just the elderly. It's not just the poor. It's everybody."

"The attitude is: If it's killing someone else, I'll deal with it tomorrow," he said. "This is coming at our doors right now.”

https://insideclimatenews.org/news/10112017/heat-wave-deaths-climate-change-misdiagnosed-health-lancet



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://bigskynet.org/pipermail/missoula-community-news_bigskynet.org/attachments/20171117/5a5a0943/attachment-0002.html>