12 votes

What's the fastest growing plant by carbon density?

Ecologists refer to this as 'gross productivity' and define it to be dry weight plant matter per area per year. In temperate climates this is likely to be a grass. Switchgrass has been proposed as a ...
9 votes

Would “Guerilla Gardening” help combat climate change and/or be feasible/legal?

I think you're up against two three at least four separate problems: The scale: rallying 1M people to plant 16k trees apiece over 20 years is no way a "guerrilla" operation; it's a mass movement. It ...
7 votes

What's the fastest growing plant by carbon density?

One way to look at it to compare like with like is to look at the photosynthetic efficiency since carbon is fixed through photosynthesis. By this measure, sugar cane comes on top, converting about 8% ...
  • 304
6 votes

Optimising crop yields without using fossil-fuel-manufactured fertiliser

(Draft answer till I get around to find some figures) There's a few ways I see to go about this: Running a Haber Bosch process or similiar with a non-fossile source for energy and H2, or finding ...
  • 2,826
4 votes
Accepted

What's the applicability of biochar?

No, and no. Current production costs of biochar are in the hundreds of dollars per tonne. (It shouldn't be that expensive.) By comparison the mining costs for coal at my neighbor, the coal mine, ...
4 votes

How can I decarbonise my domestic heating, given severe physical constraints?

The glib answer is to use less energy. The best way of doing that is fixing the fabric of the house - massively increasing insulation, massively decreasing air permeability (and as a result fitting ...
4 votes

Are there any unsustainable supply-chain issues unique to hydrogen fuel cell vehicles?

The favored anode catalyst in a hydrogen fuel cell is platinum(1) or another platinum-group element (e.g. palladium). The catalyst is required in small quantities for an individual fuel cell but of ...
4 votes

What's the fastest growing plant by carbon density?

Since grass and switchgrass already been mentioned; Hemp and Paulownia tree may be the alternative answer. They are among the fastest growing plants. For hemp, one unit land area of hemp(s) can ...
4 votes
Accepted

Direct Electrical Heating

There are three forms of heat transfer: conduction, convection, and radiation. Physically, there is no such thing as "direct electrical heating". The most "direct" way to convert electricity into ...
  • 2,406
4 votes
Accepted

For airlines that have "vowed to offer carbon-neutral flights" how do they say they plan to actually make some flights demonstrably carbon-neutral?

One of the first airlines to initiate sustainability and carbon neutrality in it operations was Qantas. It has a Carbon Action Plan, which includes things such as: Establishing carbon offsetting ...
  • 3,227
3 votes
Accepted

Why not use scarce California water for almond milk?

The issue is really with sustainability rather than scarcity, and it is also linked to ecological issues. An article in the Berkley University web site gives some background information. In order to ...
  • 981
3 votes
Accepted

Which are the 66 (65?) countries that vowed carbon neutrality by 2050 at the September 2019 UN Climate summit?

THelper did the heavy lifting, but I did some additional digging and found some more info. The official UN closing press release from the climate action summit includes this paragraph: 65 ...
  • 11.4k
2 votes
Accepted

Shortcut carbon emission trading by buying and sinking coal

"Obviously, it would be most ecologic to leave the coal where it is. But since this does not happen..." Actually, there are some who would like to buy the coal in the ground and leave it ...
  • 11.4k
2 votes
Accepted

Which climate change mitigations take longer than 12 years to see a net benefit?

Almost all of the well-known mitigation tools yield fast benefits. PV's payback is around a year. Onshore wind around 3 months, offshore wind around 9 months. The payback time on each of these three ...
  • 14.6k
2 votes

How can I separate carbon monoxide from wood gas?

If you are going to use wood gas to run a generator, don't bother removing the CO. Burn it. https://www.youtube.com/watch?v=X3KipK49v7g is a vid on making a woodgas powered truck. That said: ...
2 votes

How can I separate carbon monoxide from wood gas?

This master's thesis by Dahiru Rufai Ahmed at the university of Oulu provides a comprehensive background into the removal of CO2 from wood gas. On pages 36-37 it mentions the water-gas shift (WGS) ...
2 votes

Would “Guerilla Gardening” help combat climate change and/or be feasible/legal?

Your calculations are way off. One cubic meter of wood harvests about 1 tonne of carbon dioxide. An average tree is 0.6 cubic meters so that's 0.6 tonnes of carbon dioxide per tree. To reduce ...
  • 3,494
2 votes

Which are the 66 (65?) countries that vowed carbon neutrality by 2050 at the September 2019 UN Climate summit?

I have trouble finding that list as well. I know that in the past 19 countries already pledged to be carbon neutral by 2050 (see https://www.carbon-neutrality.global/members/). I did also find this UN ...
  • 14.2k
2 votes

Electric cars and grid power capacity

National Grid supplies the energy for the UK, and also manages the high voltage power transmission system. Each year, they prepare a Future Energy Scenarios report looking at energy needs across the ...
  • 11.4k
2 votes

How "green" is using wood as a material?

The Forest Stewardship Council (FSC) verifies forest management practices and Chain of Custody (CoC) of forest products. Chain of Custody (CoC) certification applies to manufacturers, processors and ...
  • 3,227
2 votes
Accepted

How "green" is using wood as a material?

There are simultaneous calls for not using paper in any form because it causes deforestation, but when it comes to building and making products from wood it is considered environmentally sustainable, ...
  • 3,494
2 votes

Why do most car manufacturers prefer electric batteries over hydrogen fuel cells?

Why do most car manufacturers prefer electric batteries over hydrogen fuel cells? Because it's cheaper today, easy to pack the batteries under the floor, won't decrease the range much and won't have ...
  • 3,494
2 votes
Accepted

When the topic of transport decarbonization comes up, all I hear is batteries and hydrogen. But what about renewable natural gas (RNG)?

Leakage. Hydrogen isn't a greenhouse gas. If it escapes into the atmosphere, no big deal: it'll either combine with oxygen to produce water, or it'll reach the outer atmosphere and escape. Either ...
  • 579
1 vote

How "green" is using wood as a material?

I can't give any precise number here, but using wood for a long lifetime product (housing, some furniture, etc) is actually a form of carbon storage (though maybe not the most efficient). Whereas ...
  • 131
1 vote

Why do most car manufacturers prefer electric batteries over hydrogen fuel cells?

There are a number of issues with hydrogen as an energy source. Firstly, there is a lack of infrastructure for hydrogen. The same can be said for battery charging, but slowly the number of battery ...
  • 3,227
1 vote

Is Hygenic Earth Energy feasible?

I'll answer only the "why not" question because I don't know about the feasibility of their plans. Why nobody else seems to be trying this? Because of two reasons. Firstly, if you extract ...
  • 3,494
1 vote

Is Hygenic Earth Energy feasible?

The proton.energy website is very optimistic, maybe a bit too much. I see a number of (potential) problems: The technology uses "hydrocarbon reservoirs" which is a different word for ...
  • 14.2k
1 vote

Direct Electrical Heating

For a college project, I'm looking to learn about direct electrical and biomass heating as a means of decarbonization of our college campus? Where can I learn about these? Searching for direct ...
  • 3,494
1 vote

Shortcut carbon emission trading by buying and sinking coal

My question is, what good ways are there store/sink coal? Just sinking large quantities of coal in the oceans is probably be a bad idea, and can have disastrous side effects. So what is known in this ...
  • 3,227
1 vote

Optimising crop yields without using fossil-fuel-manufactured fertiliser

Note: the plants need nitrogen (for protein synthesis), not necessarily ammonia. Ammonia however is only one source of nitrogen. So I'm using the general term nitrogen below: In practice this has ...
  • 241

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