Emission scenarios and economic impacts of climate change

[socialist]

You could only post these things if you were uninformed about the causes of climate change, which you don't seem to be curious about. The greenhouse effect causes warming, and that's what we're dealing with today. It caused it in the past too.

And you're an expert on what is causing climate change?My point is that humans have very little impact.

[waldo]

My point was that your post had nothing to do with current climate change

or this thread! There's certainly no shortage of GW/AGW/CC related threads to presume to question historical and/or (interpreted) scientific based aspects... obviously, that graphic has nothing to do with 'emission scenarios/economic impacts'.

[Michael Hardner]

My point is that humans have very little impact.

If that's your point, then posting temperatures from millions of years ago doesn't show that. Greenhouse gas levels at those times will still correlate with temperatures, when other factors are controlled for.

[socialist]

Well, I guess you aren't able to understand the intricate details of the graphic I posted. You have wasted enough of my time with your nonsense.

[Michael Hardner]

Well, I guess you aren't able to understand the intricate details of the graphic I posted. You have wasted enough of my time with your nonsense.

Ok. The last fact posted in our discussion was from me: " Greenhouse gas levels at those times will still correlate with temperatures, when other factors are controlled for. "

[-1=e^ipi]

One criticism that I've seen of quantifying the costs associated with climate change is that they generally only look at materialistic benefits, and often don't include that people value preserving the environment. However, quantifying this value and relating to a function of the amount of climate change is difficult.

Fortunately there are happiness surveys, both globally (https://en.wikipedia.org/wiki/World_Happiness_Report) and time series for some countries (http://ftp.iza.org/dp4060.pdf). Using these surveys, it is possible to estimate happiness as a function of the amount of global warming (either locally or globally) as well as other factors (such as consumption). Since happiness is positively correlated with utility, if the coefficient of relative risk aversion is known (say from looking at consumer behaviour under uncertainty) then one can infer utility as a function of global warming, consumption, and other factors.

[-1=e^ipi]

Here's something I haven't considered before.

Human blood pH and intercellular pH is around 7.4. The intercellular pH for most vertebrate species is around 7.4.

Isn't that a indication that life evolved under conditions of Ocean pH around 7.4? Does that mean ocean life is optimized with an ocean pH of 7.4? (Current pH is 8.1).

Even whales, which live in the Ocean, have a blood pH of 7.4. Although most fish species have a blood pH of 7.7-8.0 but an intercellular pH of 7.4. Is this an adaptation by fish to a less acidic ocean?

[-1=e^ipi]

New study out on global warming impacts:

http://www.nature.com/articles/nature15725.epdf?referrer_access_token=eDLT91mmHhpJa7qfX-yrJdRgN0jAjWel9jnR3ZoTv0M9qnfWTywcc-SwmqGd2vK8XXcG_rpXmqhktyHqNDHHQB042l4oAIKPtdqUD_2xZxzW69Gv1Mq5NCF9s7sNPKXqjoXQgAnwxVOfsG0ndJjdKs3BO-F0GDCDzHr98uoOyezxzIzFOPdTEqv7BTcktq8v-9gaDjl3JW7QfW1Wy5GBsw%3D%3D&tracking_referrer=www.cbc.ca

I'll have to look through it later. From what I understand, it suggests GDP per capita is optimized around an average annual temperature of 13 C. Canada, Russia, Northern Europe and Mongolia would benefit from global warming.

Edit: Richard Tol is not a big fan of this paper.

Edited October 22, 2015 by -1=e^ipi

[-1=e^ipi]

My primary criticism of the paper is that it is looking at partial equilibrium effects rather than full equilibrium effects. It looks at annual variation in output by country and compares that to temperature variation. However, obviously it takes time to adapt to climate change. So the results probably overestimate the magnitude of the impacts of climate change, but not the direction. A cross-sectional approach is probably better.

[TimG]

So the results probably overestimate the magnitude of the impacts of climate change, but not the direction. A cross-sectional approach is probably better.

The paper shows graphs with the effect of 10 degree changes on various metrics. The effects are minimal except at the high end when there is a sudden drop off. No one rational is talking about more than 4degC which makes such analysis suspect. This analysis also does not take into account that the effect of GHGs is warmer nights with a lesser effect on days so the real effect of temperature on humans working during the day would be less than suggested.

[On Guard for Thee]

Have a look at the Castle Creek Glacier. Do any of the deniers think some sort of dam is going to alleviate this?

http://www.cbc.ca/news/multimedia/glacier-melt-in-b-c-mountains-reaches-shocking-levels-1.3259647

[-1=e^ipi]

The paper shows graphs with the effect of 10 degree changes on various metrics. The effects are minimal except at the high end when there is a sudden drop off.

I think you are misunderstanding the paper. Those graphs are not of global temperature, but of local temperature. And they are mostly used in the beginning as a discussion about how temperature affects productivity. The primary result of the paper is the estimation of productivity as a function of local temperature using empirical data (and this estimate is quadratic and doesn't have this sudden drop off). They then go on to predict changes in global output due to climate change using RCP 8.5. I don't agree with RCP 8.5, but that doesn't affect the validity of the estimate of how temperature affects productivity.

This analysis also does not take into account that the effect of GHGs is warmer nights with a lesser effect on days so the real effect of temperature on humans working during the day would be less than suggested.

Yes, that is true. Though I think not taking into account that adaptation takes time is of a bigger concern.

Edited October 22, 2015 by -1=e^ipi

[On Guard for Thee]

2015...hottest year on record. So much for the GW hiatus idea.

[Michael Hardner]

Cite:

https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/10/21/after-record-shattering-september-2015-in-commanding-lead-for-earths-hottest-year-on-record/

"Planet Earth is on a high temperature record-breaking tear this year, which shows no sign of relenting. 2015 is, by far, on track to become the warmest year in recorded history.

NOAA reports today the globally-averaged temperature for September 2015 was the warmest of all previous Septembers on record, dating back to 1880, and by an unprecedented margin of 0.19 degrees."

[TimG]

Planet Earth is on a high temperature record-breaking tear this year, which shows no sign of relenting. 2015 is, by far, on track to become the warmest year in recorded history.

And why should we care about it?

[Michael Hardner]

And why should we care about it?

Care as much as you would like to. Most will find it interesting, if not concerning.

[Michael Hardner]

And since this is on-topic:

http://www.cbc.ca/news/technology/climate-change-economy-1.3282446

Compared to what it would be without more global warming, the average global income will shrivel 23 per cent at the end of the century if heat-trapping carbon dioxide pollution continues to grow at its current trajectory, according to a study published Wednesday in the scientific journal Nature.

Some countries, like Russia, Mongolia and Canada, would see large economic benefits from global warming, the study projects.

[TimG]

Compared to what it would be without more global warming, the average global income will shrivel 23 per cent at the end of the century if heat-trapping carbon dioxide pollution continues to grow at its current trajectory, according to a study published Wednesday

Assuming countries don't develop and don't adapt and assuming the assumptions built into the analysis have any connection to the real world.

Lastly: how much would global growth be reduced if the cost of energy is doubled or tripled over the no-CO2 policy baseline? The difference between that number and the 23% is the only number that matters.

[Michael Hardner]

The difference between that number and the 23% is the only number that matters.

Not if you're Canadian. If you're against the TPP, ostensibly because it hurt's Canada's economy, then you may be in favour of Climate Change. Not "you" specifically, but "one".

[-1=e^ipi]

2015...hottest year on record. So much for the GW hiatus idea.

The slow down still occurred. 2015 won't change that.

[-1=e^ipi]

@ Michael - That's the paper I was referencing a few posts ago...

But yeah, it's looking like Canada has to justify mitigation policy on the basis of charity, not on self interest. Which is fine, but I doubt politicians will be honest.

Assuming countries don't develop and don't adapt and assuming the assumptions built into the analysis have any connection to the real world.

No, the paper accounts for development. Though it probably underestimates adaptation since it's a partial equilibrium analysis as I said earlier.

[-1=e^ipi]

Lastly: how much would global growth be reduced if the cost of energy is doubled or tripled over the no-CO2 policy baseline? The difference between that number and the 23% is the only number that matters.

Suppose the production is roughly Cobb-Douglas and energy's share of income is roughly 5%.

http://www.eia.gov/todayinenergy/detail.cfm?id=18471

This means that doubling energy prices would reduce GDP per capita by 1 - (1/2)^0.05 = 3.4%.

Tripling of energy prices would reduce GDP per capita by 1 - (1/3)^0.05 = 5.3%.

Edited October 22, 2015 by -1=e^ipi

[TimG]

Suppose the production is roughly Cobb-Douglas and energy's share of income is roughly 5%.

Energy costs permeate the economy. The indirect energy costs baked into every good or service sold are a much greater concern than the direct purchases of energy by consumers. Also, the cost of energy is a more important factor in developing economies. Edited October 22, 2015 by TimG

[-1=e^ipi]

Energy costs permeate the economy. The indirect energy costs baked into every good or service sold are a much greater concern than the direct purchases of energy by consumers.

This doesn't refute what I wrote.

Also, the cost of energy is a more important factor in developing economies.

This might. The Cobb-Douglas approximation probably doesn't hold exactly. But it isn't that bad. Energy's share of income in developing countries is like 10% or so. So at worst you can just double the earlier numbers.

[TimG]

This doesn't refute what I wrote.

Well it does because what you wrote is only fraction of the costs and that makes it a misleading figure to quote.