At the Paris climate conference a surprise result was for the world to aim to hold “the increase in … temperature to well below 2°C … and to pursue efforts to limit the temperature increase to 1.5°C”.
Fred Pearce in the New Scientist now takes a look at what some are saying needs to be done.
It is generally agreed that attaining 1.5°C will involve overshoot and negative emissions, sucking CO2 out of the air. The idea according to Joeri Rogelj and others is that we should limit emissions to 800 GT of CO2 by 2050 when we should reach net zero emissions. Then we should suck 500 Gt of CO2 out of the air from 2050 to 2100.
Pearce says a study looked at several ways to chemically absorb CO2 directly from the air. They are all prohibitively expensive, costing about $270 trillion and consuming a quarter of the world’s energy supply.
The easy way would be to plant lots of trees. But planting enough to soak up 500 Gt of CO2 over 50 years would require 10 million square kilometres, an area as big as the United States. It’s simply not possible.
The article then looks at three technologies that might together achieve the aim.
The first is bioenergy with carbon capture and storage (BECCS), where trees are grown then burnt to produce power. The carbon emitted is captured and buried. We have the capacity to bury 500 GT of CO2 about 20 times over in former gas and oil formations or in saline aquifers, if you think that’s a good idea. Problem is compressing and transporting the stuff. Also 500 Gt would still require somewhere between 3.8 and 7 million square kilometres of land.
Kevin Anderson of the Tyndall Centre has ridiculed techno-utopian fantasies associated with negative emissions and BECCS in particular. See here, here and here.
Pete Smith of the University of Aberdeen, UK, who headed a global study of negative emissions options published during the Paris conference thinks BECCS is the most promising option.
Pressing on, Pearce identifies biochar as a possibility, where agricultural waste like straw, manure and unused food is been pyrolysed to charcoal, ground up and ploughed into the soil. Smith reckons biochar could provide up to 125 Gt of the negative CO2 required.
The third technology is the cultivation of microalgae, already undertaken in Australia, for example, to produce “biodiesel, new algae-based food, animal feed and nutraceuticals”.
Brian Walsh at the International Institute for Applied Systems Analysis (IIASA), the same place where Rogelj hangs out, reckons microalgae could be good for 25 Gt of CO2 a year. Microalgae can be grown on non-arable land using fresh, brackish or saline water, so it doesn’t compete with agriculture for land.
By mid-century, there could be up to 50 million hectares growing billions of tonnes of biomass and feeding 10 per cent of the world’s livestock.
Whether these technologies will work or not I was disappointed by the climate science assumptions. The strategies are based on the notion that limiting emissions to 430 ppm will limit temperatures to an increase of 2°C. In the post The game is up in June 2014 I pointed out that in terms of CO2 equivalence, counting all greenhouse gases, we were already at 480 ppm.
In that post I quoted David Spratt:
- We have to come to terms with two key facts: practically speaking, there is no longer a “carbon budget” for burning fossil fuels while still achieving a two-degree Celsius (2°C) future; and the 2°C cap is now known to be dangerously too high.(My bold)
Rather than go over it all I’ve listed a number of related posts at the end of The folly of two degrees.
I’ve been saying that for a safe climate we need zero net emissions by 2030 and need to take CO2 out of the atmosphere to get concentrations below 350 CO2e ppm by 2050.
David Spratt has now published a post at Climate Code Red which asks how fast we need to go if we take Paris and 1.5°C seriously. They say:
- Justin Gillis of the New York Times reported Sunday that limiting warming to 1.5°C would require global industrial greenhouse gas emissions to come to an end by 2030. Climate researcher Glenn Peters has projected that meeting the 1.5C target would require a global fossil fuel phase-out between 2025 and 2030, as well as a large-scale effort to remove excess carbon dioxide from the atmosphere. Similarly, a group of scientists writing in The Hindu found that developed countries such as the U.S. would need to reach zero emissions in “the next 5-10 years” for a 50 to 66 percent chance of limiting warming to 1.5°C.
All is not lost. We still have a planet full of clever brains at work solving problems. Consider
http://cafe.foundation/blog/uta-scientists-make-liquid-hydrocarbon-fuels-in-one-step/
and
http://www.nasa.gov/centers/ames/research/OMEGA/#.VtTS7Pl94dg
My contribution is the notion of algal foam which involves a CO2 rich gel foam which propagates algae for harvesting over several days with the chemical gel being recycled. The inspiration for this comes from the way algae grow on the ice crystals in the Arctic regions.
Give it a few more years and the will be dozens of CO2 capturing solutions which are self funding.
BilB, if microalgae can be cranked up to 25 Gt of CO2 a year we are in good shape. That’s about half what we are putting into the atmosphere at present.
Thanks for the links.
I’m encouraged by the fact that some scientists are looking at what they think needs to be done.
Bilb: The US extracts CO2 from seawater as part of their process for producing inorganic, renewable Jet A fuel on nuclear aircraft carriers A similar process could be used to produce CO2 for injection underground.
One of the problems I have with the renewable transport fuel debate is that there is a group of scientists whose research careers depend on progressing biofuels and another group whose careers depend on the progress of inorganic processes like the one used to make Jet A. (I support the inorganic processes because they have less impact on the environment.)
The difference, John D, is the source of the energy. For countries with abundant nuclear, geothermal, hydro, wind or wave energy, the inorganic process might make sense. For countries with abundant solar energy the organic process might make sense.
The energy demand is huge, so I doubt that a “one or the other” argument makes any sense at all. I think that this is a this, that, and any other renewable technology you can think of, to add to the fuel sourcing mix. This is the one thing that is so awesome about renewable energy, it is open to anyone, anywhere to participate in as an energy producer.
This is why Rockefeller and the coal lobby were prepared to lie, cheat and manipulate ethanol fuel out of the energy mix crushing Henry Ford’s dream for renewably fuelled vehicles in the process.
Bilb: The inorganic processes require electricity and water plus CO2 for hydrocarbon production or nitrogen for ammonia production. The power can come from any source of power including solar.
Bilb: Agree that different countries will have to use different energy sources and in some cases may influence the bio/inorganic balance.
The problems with bio that don’t affect inorganic can include:
-High impact due to need for lots of land and water.
-Vulnerable to disease, insect plagues, climate change plus drought and flooding rains.
I don’t share your concerns on bio energy, John. If you look at NASA’s Omega project the system float on sea water and feeds off sewage. I support the use of palm oil as a local fuel where it does not involve forest clearing for its growth. At 4000 litres per hectare it is 1/3 the litre yield of cane ethanol, but requires little refining to make bio diesel. A village with several hectares in palm can produce most of their liquid fuel energy requirements reducing the quantity of tradable goods required to achieve a more modern life style.
It is about responsible development, and that goes for all technologies.
By far the most effective local energy production vehicle is solar PV(T). Energy conversion yields from plants are around 3%, from solar thermal to electricity 15%, from solar PV 13% to 45%, from solar PVT 45% to 80%.
But biomass even at 3% is extremely effective as nature is so efficient at covering every fertile surface with life.
Bilb: I haven’t got time to chase the links but palm oil is leading to massive jungle clearing and US style ethanol from corn has pushed up corn prices to the point where it is causing unrest in countries where corn is an important food as well as causing water consumption problems in the US.
I have no problem with the idea that some fuel will come from genuine bio-waste but my analysis favours low impact fuels.
You can’t kill a technology, John, because some people are acting illegally with greed driven environmental degradation. That activity is going on all over the world including Australia to grow food crops predominately. Brazil uses just 2% of their arable land to grow cane for ethanol and to great effect powering their vehicle fleet. I’ve covered US corn ethanol extensively and that is an exercise in extremely poor technique at every level. Meanwhile the US refuses to use cane for ethanol, another anomaly that costs those farmers dearly.
Ethanol and bio diesel powering plug in electric hybrids is a winning combination that could eliminate petrol in Australia in as little as 20 years with the bulk of the motive energy coming from solar PV’s. It will take a little more time. Hyundai are about to release their version of the 50klm electric range hybrid. If they hit the price level right that could very well get the electric conversion ball rolling . Apart from that there is a move to get straight EV’s up to a standard range of 300 klms.