Climate Change / Global Warming Discussion

[wcalvin]

Re: Regarding correlating temperature to social impact, believe it or not, I vividly recall my 8th grade social studies text book in India associating large populations and high population densities in South Asia and other parts of South East Asia to the tropical temperatures there. Go figure

With no frost to limit the growing seasons and enough tropical rain, they can get 2-3 crops each year, increasing the carrying capacity, i.e., higher populations.

 

[SwedishAdvocate]

Wonder if a rise of ~9 inches/23 cm in global mean sea level made a difference here...

@ 0:08

 

[montgom626]

Great Lakes ice cover surges, most in 20 years!!!

Great Lakes ice cover plunges and surges, with record still in sight


The amount of the Great Lakes basin covered with ice topped 90% this week, the most in at least 20 years, according to the Great Lakes Environmental Research Laboratory in Ann Arbor, Mich. Freezing temperatures are expected throughout the week, so the lake ice has a fair chance of breaking 1979's record of nearly 95%, according to forecaster Jia Wang

Comment: Does this make any sense????

 

[Doug_G]

Yes, makes perfect sense, in that it has nothing whatsoever to do with global climate.

 

[JRP3]

It might. Climate change may have shifted the flow of the jet stream so that it's pulling colder air lower, and it's moving more slowly so the cold air sticks around longer. Meanwhile Alaska has had one of it's warmest winters ever, as have other parts of the planet. You can't focus on one area and ignore the rest.

 

[Doug_G]

Yes, and a warming climate will result in more extremes, including extreme cold... but you can't pin any single weather event on climate. Weather is weather. Climate is statistics.

It's equally silly to say, "Wow, this was the hottest day on record... must be global warming." That is also just as false.

 

[Dave EV]

Yes, and a warming climate will result in more extremes, including extreme cold...

Somewhat true, but extreme hot temperatures are (and will continue to be) much more common than extreme cold temperatures. The last decade has record hot temperatures exceed record cold temperatures by over a 2-1 ratio. If the climate were not warming, it'd be about equal.

 

[gg_got_a_tesla]

The situation in eastern Australia is getting worse:

BBC News - Cattle prices tumble amid eastern Australia's drought

 

[montgom626]

methane, a potent greenhouse gas,

Methane is a potent greenhouse gas, around 20 times more effective per molecule than carbon dioxide. An increased release from the ocean into the atmosphere could further intensify the greenhouse effect.

Climate change and methane hydrates World Ocean Review


Comment: I am more worried about methane now.

 

[SwedishAdvocate]

Methane is a potent greenhouse gas, around 20 times more effective per molecule than carbon dioxide. An increased release from the ocean into the atmosphere could further intensify the greenhouse effect.

Climate change and methane hydrates World Ocean Review


Comment: I am more worried about methane now.

Oh Montgomery... Don’t you mean you’ve been more worried about methane since 12-18-2013, 05:45 AM?

Six Forgotten Greenhouse Gases Methane is the real problem, not CO2Six Forgotten Greenhouse Gases | Weather Underground

Methane

You can say it as nicely or scientifically as you’d like, but the bottom line is, cows are farting out a lot of methane and it’s pretty bad for the environment. Methane is produced as a byproduct of microbial life, and many of these microbes live in the guts of cattle, which we keep in large numbers, mostly for beef and dairy products. Methane is also emitted in large quantities from rice paddies, as the microbes need moisture, and rice paddies have a significant amount of it. A 2010 study found that paddies in Cambodia alone emitted nearly 380,000 tons of methane from 2005-2006, the equivalent of burning 16.8 million barrels of oil, according to the EPA. For context, the United States consumed 6.8 billion barrels of oil in 2011, according to the U.S. Energy Information Administration.

Just jump back to post #841 for one rebuttal of this little misinformation deja vu…

 

[TheTalkingMule]

Great Lakes ice cover plunges and surges, with record still in sight


The amount of the Great Lakes basin covered with ice topped 90% this week, the most in at least 20 years, according to the Great Lakes Environmental Research Laboratory in Ann Arbor, Mich. Freezing temperatures are expected throughout the week, so the lake ice has a fair chance of breaking 1979's record of nearly 95%, according to forecaster Jia Wang

Comment: Does this make any sense????

Sure it does. The jet stream relies on the variance between Arctic temperatures and temperatures at the equator. As the Arctic warms faster than the equator, the jet stream loses energy, loses speed and therefore is more likely to meander like a stream would on a flat plain vs. a steep hill. These deeper and slower meanders in the jet stream allow for polar vortexes to drop down where you wouldn't normally find them like they have for the US this year and Europe a few years back.

I'm not even remotely a scientist, but I'd imagine this is a preamble to the truly ice-free summers at the North Pole that have been predicted since back in 2007. In my mind this polar air that keeps diving down to us has to be causing an equal-and-opposite warming up near the pole that's probably affecting the normal winter ice buildup.

Of course I'm completely talking out of my rear-end, but it seems logical to me.

 

[SwedishAdvocate]

Here’s a new one:

I was at a sustainable transportation seminar the other day and one of the presenters put up a slide showing that bicycles contribute more to the CO2 problem than electric vehicles do... unless the cyclist is a vegetarian. I suppose we'll need a carbon tax on bicycles too!

I don’t think I currently possess the skill set necessary to blow that one to pieces. But maybe someone else does…

 

[JRP3]

I guess the argument is that emissions from raising animals and processing and transporting meat to provide calories could be higher than running an EV from a renewable source. Could be true I suppose.

 

[tigerade]

I don’t think I currently possess the skill set necessary to blow that one to pieces. But maybe someone else does…

Let me know if my attempt to blow it to pieces is any good.

 

[SwedishAdvocate]

From that thread:

I was at a sustainable transportation seminar the other day and one of the presenters put up a slide showing that bicycles contribute more to the CO2 problem than electric vehicles do... unless the cyclist is a vegetarian. I suppose we'll need a carbon tax on bicycles too!

That's silly. The problem is the consumption of beef, not using a bicycle. (Full disclosure: I like beef.)

- - - Updated - - -

Let me know if my attempt to blow it to pieces is any good.

Works for me. Thanks. :smile:

 

[Jeff Miller]

Here’s a new one:

I don’t think I currently possess the skill set necessary to blow that one to pieces. But maybe someone else does…

Sounds hard to believe on face value. Here's a back of the envelope calculation.

A 155 lb person running at 5 mph uses about 563 calories per hour.
So 94 calories to run 1 mile. Biking is about 3x more efficient than running so you'd use around 31 calories
in direct energy.
But the embedded energy/carbon cost of our food is extremely high (raising animals, fertilizer, food waste, transport etc).

This site estimates the total carbon footprint of various diets:

The carbon foodprint of 5 diets compared

A typical American diet of 2600 kc per day produces 2.5 t of CO2e per year. That is 13.7 pounds per day, or
.005 lbs per calorie.

So using 31 calories to bike a mile produces 31 * .005 = .16 lbs of CO2e.

The average model S is using 335 wh per mile not including charging and vampire losses. If we assume
20% extra for vampire and charging, it's about 400 wh/mile. The carbon emissions of the US grid are
very roughly what they would be if it were all natural gas (nukes and hydro cancel coal). A kwh of electricty
from natural gas releases 1.2 lbs of CO2. With transmission losses, say 1.3. So the Model S running on this average grid produces
about .4 * 1.3 = .5 lbs of CO2.

So very roughly, I would estimate that biking is 3x more carbon efficient than driving a Model S assuming a typical american diet.

(This isn't even counting the enormous energy cost to build the car compared with building the bike).

 

[JRP3]

Powered from renewables then an EV would indeed have lower CO2 emissions. Throw in methane and total greenhouse emissions of an EV from renewables would be even better. (Obviously not counting construction emissions.)

 

[Jeff Miller]

Yes. But energy construction costs for a car are huge compared to a bike so we shouldn't neglect them.
In "Sustainable Energy without the hot air" Mackay
estimates that it takes 76,000 kwh of energy to build an ICE car:
Ch 15 Page 90: Sustainable Energy - without the hot air | David MacKay
Over a 15 year lifespan of the car, that comes to 14 kwh hours per day.
Assuming again electrical energy from natural gas is used for energy (just to get
a ballpark figure) and assuming it takes about as much energy to build an EV
as it does an ICE, construction costs add another 18 pounds of CO2 per day
over the life of the car. You'd have to biking/driving over a hundred miles a day
on a typical diet for the purely renewable powered EV to be the lower carbon option...
bikes are hard to beat.

 

[gg_got_a_tesla]

BBC News - Malaria spreads to higher altitudes

 

[Robert.Boston]

^^ don't forget to add a discussion point. Remember, no more "here's a link" posts, please.