Showing posts with label global warming. Show all posts
Showing posts with label global warming. Show all posts

Feb 23, 2009

Surface Radiation Calculations


Basic system thermodynamics revisited (click image to view full size)
A colleague of mine emailed me an article (pdf link) containing the above figure. The author Ashworth (2008) contends among many things that the radiation energy balance shown in the figure above is wrong, and that it violates 1st and 2nd law of thermodynamics. I am writing this post to show that Ashworth is completely off base on that point and is not even close to interpreting the above figure correctly. I am not able to decipher any 2nd law implications from the figure though.
I don't have clear arguments or time right now for the all graphs of CO2/warming shown subjectively. It could go either way.

But first, imo, the author does not even know how to define a system for performing energy balances. Because of this he does not know how to add the necessary terms to achieve a 1st law energy balance. Clearly, if you look at the total energy balance, the incoming and outgoing solar radiation fluxes at the outer boundary of the atmosphere add up fine (342 coming in and 107+235 going out at the atmosphere level, from space).

This author is forgetting the fact that the earth is round and receives radiation at different times throughout the day and radiates it back. Consequently it is possible to radiate 390 (+ 78+24 also shown in the image) because earth is also getting back radiation of 324 apart from the 168.
Further if you do a surface balance that also adds up fine. See image of my excel calculation below.

The original paper from which they obtain the Fig 8 is here (pdf) where towards the end the authors clearly put forward the errors etc in the model and still clearly show that an energy balance has been achieved. Further the Ashworth "paper" is written like an opinion piece and (gasp) and shows lack of simple mathematical concepts.

But the bigger issue with anthropogenic CO2 related global warming is not the average daily solar fluxes, it is the release of the chemical energy trapped for millions of years in carbon bonds. The resulting CO2 release into the atmosphere is what is being considered as a precursor to global climate changes.

I should add at this point, my personal view on the subject of global warming and climate change is still not firmed up. I am merely an advocate for efficient use of resources, irrespective of whether they are carbon based or not. But what really bothers me sometimes is people pointing fingers at others, but making similar mistakes themselves.

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Dec 18, 2008

Opinion: Are win-win solutions to our energy and environmental problems possible?




Image credits: Apollo Alliance
Folks at the Environmental Economics blog have a great ongoing discussion on whether "green policies" would create additional jobs in the long run. John Whitehead thinks that "Green government fiscal policy doesn't create jobs in the long run", whereas Mark Thoma thinks that green policies would create jobs in the short run and help stabilize the economy. Mark also argues that the lack of empirical evidence for green policies creating additional jobs does not apply to the current state of the economy.

My 2 ¢: I agree with Mark that green policies would create incentives for job creation in the short-run. However, this should be balanced against the job losses from the traditional sectors of the industry in the long-run. Examples include the potential job-losses in the U.S. (& Indian/Chinese) coal mining industry because of CO2 regulations. Various stakeholders (government, industry, workers and the public) should be involved in environmentally and economically-sound policy making.

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Sep 17, 2008

Projected (2030) greenhouse gas abatement potentials and costs



[SVG GHG abatement potentials and prices for clean energy technologies] (Using the link to view the image requires a stand alone SVG viewer and your browser needs to be configured to use this player)

The data are taken from a McKinsey report. I have compared only renewable energy technologies and carbon capture and sequestration (CCS) on this figure. The size of the circle approximately indicates the relative CO2 abatement potential in megatons of CO2 equivalents. (The report indicates that energy conservation, mainly by switching off electronics and computers, switching from incandescents to CFLs constitutes "low-hanging fruit". On the other hand, clean energy technologies such as wind, solar PV etc. require some investment in order to realize CO2 emission reductions. The cheapest among the renewables is producing cellulosic biofuels. Another obvious "low-hanging fruit" is the reduction of industrial non-GHG emissions; 250 MTCO2 equivalents at next to nothing prices represents a huge source of cheap carbon credits.This is my first SVG file (created using Gnuplot).

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Jun 30, 2008

Politics of climate change legislation

Here is an inside view of how the recent Lieberman-Warner climate change bill was debated in the Senate. It is funny (and sad) how some senators talk of cap & trade as a carbon tax. The notion that one can generate revenues and jobs by a cap & trade system completely intrigues me. Meanwhile the Chicago Climate Exchange already has a voluntary trading system for carbon. When is the best time to take action against global warming? NOW. As Senator Boxer points out, waiting to legislate until the gas price comes down will be a fatal mistake.

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Jun 1, 2008

Save the planet by driving a hummer?

NPR has interesting interview with Spencer Reiss on how consumer choices may effect global greenhouse gas concentrations. Find the link here . One central theme that recurs in the discussion is the concept of system-wide analyses to determine whether something is good for the environment or not. This is also what life cycle analyses (LCA) does.

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