Ask me anything on Climate and Energy

[sayak83]

So...
I teach three graduate level courses on Climate Change Physics, Sustainable Energy Technology and Combustion Science and Biofuels. Since there seems to be a lot of politically charged what-aboutery going on in these topics in the forum, I thought it would be a good idea to open a thread for anyone to ask me any question related to climate change science and Energy Technology Transitions going on in the world. Hopefully I can provide science based insightful answers...at least I will try.

So...shoot.

 

[Guitar's Cry]

One of the arguments I often hear is how climate change was predicting catastrophic end-of-the-world scenarios that haven't come to fruition. But from my own education, it appears that many of the predictions have been occurring: droughts, severe weather, sea-level rise, etc.

What have climate change predictions gotten correct or incorrect, and what may still yet occur?

 

[Aštra’el]

As the climate changes, what new kinds of storms might people come to expect?

 

[RestlessSoul]

Are we in fact, already ****ed?

 

[Audie]

So...
I teach three graduate level courses on Climate Change Physics, Sustainable Energy Technology and Combustion Science and Biofuels. Since there seems to be a lot of politically charged what-aboutery going on in these topics in the forum, I thought it would be a good idea to open a thread for anyone to ask me any question related to climate change science and Energy Technology Transitions going on in the world. Hopefully I can provide science based insightful answers...at least I will try.

So...shoot.

Why such wide swings in climate
in past 10k years

 

[Audie]

One of the arguments I often hear is how climate change was predicting catastrophic end-of-the-world scenarios that haven't come to fruition. But from my own education, it appears that many of the predictions have been occurring: droughts, severe weather, sea-level rise, etc.

What have climate change predictions gotten correct or incorrect, and what may still yet occur?

People were able to walk the Bering "land
bridge" which was wider than the state of Alaska is now. Sea level has been rising for some time.

 

[icehorse]

Been looking into this a lot, I have soooooo, many questions

1 - It seems we could make far better use of the fact that once you get about 4-6 feet underground, it's always around 54 degrees. Why aren't we making better use of that geothermal property to heat and cool our homes and greenhouses? Some people are doing it, why isn't it far more common?

2 - What do you think our best non-battery storage technologies will be? Huge cookoo clock thingies? Sand batteries? compressed gasses?

3 - How's algae diesel coming along?

4 - Why aren't we sinking HUNDREDS of BILLIONS of dollars into fusion research?

That's a start.

 

[exchemist]

So...
I teach three graduate level courses on Climate Change Physics, Sustainable Energy Technology and Combustion Science and Biofuels. Since there seems to be a lot of politically charged what-aboutery going on in these topics in the forum, I thought it would be a good idea to open a thread for anyone to ask me any question related to climate change science and Energy Technology Transitions going on in the world. Hopefully I can provide science based insightful answers...at least I will try.

So...shoot.

I am interested in how realistic it is now thought to be for hydrogen to play a role as an energy storage and transfer medium. I am thinking of two applications: motive power for trucks, and home heating (to replace piped natural gas).

I imagine a great depends on the prospects for more efficient large-scale electrolysis (though blue hydrogen could be a useful temporary source, to help hydrogen achieve scale quickly enough to get the truck and heating applications to take off commercially.)

What is the current thinking on this?

 

[Heyo]

Are we in fact, already ****ed?

Depends on what you mean by "being ****ed".
We may or may not have already stepped over some tipping points. I.e. even if we go CO2 neutral in the near future, temperatures will keep on rising due to processes we set into motion that can't be easily reversed. E.g. methane emissions from former permafrost soil.

 

[Subduction Zone]

I am interested in how realistic it is now thought to be for hydrogen to play a role as an energy storage and transfer medium. I am thinking of two applications: motive power for trucks, and home heating (to replace piped natural gas).

I imagine a great depends on the prospects for more efficient large-scale electrolysis (though blue hydrogen could be a useful temporary source, to help hydrogen achieve scale quickly enough to get the truck and heating applications to take off commercially.)

What is the current thinking on this?

I could see hydrogen being used in home heating. But I would worry quite a bit if use to replace natural gas in cooking. It will ignite at about half the concentration of natural gas. Though even that may not be a problem if extra safety features were engineered into the ovens (and wouldn't we hate some people complaining about the "nanny state" when a hydrogen stove refuses to turn on when there is no electricity).

6 Differences between Hydrogen and Natural Gas

 

[exchemist]

I could see hydrogen being used in home heating. But I would worry quite a bit if use to replace natural gas in cooking. It will ignite at about half the concentration of natural gas. Though even that may not be a problem if extra safety features were engineered into the ovens (and wouldn't we hate some people complaining about the "nanny state" when a hydrogen stove refuses to turn on when there is no electricity).

6 Differences between Hydrogen and Natural Gas

In the days of town gas, which I remember from childhood, we managed fine. That was a mixture of H2 and CO. When natural gas came along, all the appliances needed new burners to cope with the different combustion characteristics (chiefly the lower flame speed of CH4, as I recall). But it got done quite smoothly. This would be changing them back, essentially.

I also remember that the type of electric igniter had to change. With town gas you could use a hot filament, but with methane it had to be a spark.

 

[Subduction Zone]

Depends on what you mean by "being ****ed".
We may or may not have already stepped over some tipping points. I.e. even if we go CO2 neutral in the near future, temperatures will keep on rising due to processes we set into motion that can't be easily reversed. E.g. methane emissions from former permafrost soil.

Plus the existing CO2 will continue to warm us for quite some time. It is like going to bed and piling on a bunch of extra blankets because it is too cold. It takes a while to get to the new equilibrium temperature. And one may end up throwing off half of the blankets because they are too many. Sadly that is rather difficult to do with the atmosphere. It takes a long time to get excessive CO2 out.

And that leads me to my question for the OP:

If we became carbon neutral today what would be the "new normal" temperature? In other words, how much is the temperature going to go up due to what we have already added?

 

[Subduction Zone]

In the days of town gas, which I remember from childhood, we managed fine. That was a mixture of H2 and CO. When natural gas came along, all the appliances needed new burners to cope with the different combustion characteristics (chiefly the lower flame speed of CH4, as I recall). But it got done quite smoothly. This would be changing them back, essentially.

I also remember that the type of electric igniter had to change. With town gas you could use a hot filament, but with methane it had to be a spark.

Yeah, but maybe without the CO

What I am afraid of is a unit not igniting, but one could probably include a switch of some sort that would shut off the H2 if there was no heat from combustion. I will walk back my worries a bit since it does not appear to be an overwhelming engineering problem. We may not be able to use hydrogen during a power outage, as we can with natural gas. That is about the only drawback that I can see.

 

[exchemist]

Yeah, but maybe without the CO

What I am afraid of is a unit not igniting, but one could probably include a switch of some sort that would shut off the H2 if there was no heat from combustion. I will walk back my worries a bit since it does not appear to be an overwhelming engineering problem. We may not be able to use hydrogen during a power outage, as we can with natural gas. That is about the only drawback that I can see.

Yes. I had a look at your link but from that I didn't see anything insuperable, given that domestic cookers and gas fires worked fine on town gas in the 1960s. Leakage didn't seem to be a major issue - though it's true the local gas holder blew up once, when I was a kid. I never knew the reasons why. As for unlit burners, surely a thermocouple to detect the flame after ignition would deal that, as it already does in every system I've been involved with.

 

[Subduction Zone]

Yes. I had a look at your link but from that I didn't see anything insuperable, given that domestic cookers and gas fires worked fine on town gas in the 1960s. Leakage didn't seem to be a major issue - though it's true the local gas holder blew up once, when I was a kid. I never knew the reasons why. As for unlit burners, surely a thermocouple to detect the flame after ignition would deal that, as it already does in every system I've been involved with.

I know very little about the safety features of modern stoves, but I do have a friend of mine who was not all that familiar with gas and she messed up somehow and was almost overcome by her stove. No explosion, but enough to make her ill.

But as you pointed out it should not be an insurmountable engineering problem. Oh, and my outdoor propane powered grill does not have such safety features. Turn it one and it goes. Definitely not for indoor use.

 

[exchemist]

I know very little about the safety features of modern stoves, but I do have a friend of mine who was not all that familiar with gas and she messed up somehow and was almost overcome by her stove. No explosion, but enough to make her ill.

But as you pointed out it should not be an insurmountable engineering problem. Oh, and my outdoor propane powered grill does not have such safety features. Turn it one and it goes. Definitely not for indoor use.

That sounds like poor combustion, leading to CO fumes accumulating, which you can get with any fuel system. Methane doesn't make you ill. I have a CO alarm fitted in the kitchen, where the boiler (furnace) lives, which is fairly standard practice.

 

[Subduction Zone]

That sounds like poor combustion, leading to CO fumes accumulating, which you can get with any fuel system. Methane doesn't make you ill. I have a CO alarm fitted in the kitchen, where the boiler (furnace) lives, which is fairly standard practice.

Are you sure?

The Critical Dangers Of Methane Gas Poisoning And Exposure

 

[exchemist]

Are you sure?

The Critical Dangers Of Methane Gas Poisoning And Exposure

There is something badly wrong with the information in that link. It says, so far as I know correctly, that the risk from methane is not poisoning but asphyxiation, by displacement of the air. However it says that carbon monoxide is similar, which is appallingly wrong.

CO binds to the iron in haemoglobin in the blood more powerfully than oxygen does, thus preventing uptake of oxygen. CO poisoning is characterised by cherry red lips, due to the deep colour of carboxyhaemoglobin. You only need a fairly low concentration to get poisoned by it.

Methane does not bind chemically in the body so it simply act as a bulk gas taking the place of oxygen, when present in very large quantities. Nitrogen or CO2, do the same of course (A man I knew at a refinery died by putting his head into an open inspection hatch at the top of a column that was being purged with N2. He couldn't smell anything but there was no oxygen so he passed out - and died. Tragic - and of course there was a massive inquest into safety procedures afterwards.)

Commercial methane is adulterated with an added odour ( a mercaptan, I think) to make it smell bad, so that nobody could get into an atmosphere with high concentration of it without being immediately aware of a gas leak.

 

[Heyo]

Nitrogen or CO2, do the same of course

Nope for the CO2. It also binds to haemoglobin, the same as CO and O2. That's the way it gets out of the body, the same way the O2 got in.

 

[Truthseeker]

People were able to walk the Bering "land
bridge" which was wider than the state of Alaska is now. Sea level has been rising for some time.

I can answer that one. The temperature certainly changed then, but it happened much more slowly than now.